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1
Bond, Daniel R., and Derek R. Lovley. "Electricity Production by Geobacter sulfurreducens Attached to Electrodes." Applied and Environmental Microbiology 69, no. 3 (March 2003): 1548–55. http://dx.doi.org/10.1128/aem.69.3.1548-1555.2003.
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ABSTRACT Previous studies have suggested that members of the Geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. In order to better understand this electron transfer process for energy production, Geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate or hydrogen was the electron donor. The electron-accepting electrodes were maintained at oxidizing potentials by connecting them to similar electrodes in oxygenated medium (fuel cells) or to potentiostats that poised electrodes at +0.2 V versus an Ag/AgCl reference electrode (poised potential). When a small inoculum of G. sulfurreducens was introduced into electrode-containing chambers, electrical current production was dependent upon oxidation of acetate to carbon dioxide and increased exponentially, indicating for the first time that electrode reduction supported the growth of this organism. When the medium was replaced with an anaerobic buffer lacking nutrients required for growth, acetate-dependent electrical current production was unaffected and cells attached to these electrodes continued to generate electrical current for weeks. This represents the first report of microbial electricity production solely by cells attached to an electrode. Electrode-attached cells completely oxidized acetate to levels below detection (<10 μM), and hydrogen was metabolized to a threshold of 3 Pa. The rates of electron transfer to electrodes (0.21 to 1.2 μmol of electrons/mg of protein/min) were similar to those observed for respiration with Fe(III) citrate as the electron acceptor (Eo′ =+0.37 V). The production of current in microbial fuel cell (65 mA/m2 of electrode surface) or poised-potential (163 to 1,143 mA/m2) mode was greater than what has been reported for other microbial systems, even those that employed higher cell densities and electron-shuttling compounds. Since acetate was completely oxidized, the efficiency of conversion of organic electron donor to electricity was significantly higher than in previously described microbial fuel cells. These results suggest that the effectiveness of microbial fuel cells can be increased with organisms such as G. sulfurreducens that can attach to electrodes and remain viable for long periods of time while completely oxidizing organic substrates with quantitative transfer of electrons to an electrode.
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Fang, Xin, Shafeer Kalathil, Giorgio Divitini, Qian Wang, and Erwin Reisner. "A three-dimensional hybrid electrode with electroactive microbes for efficient electrogenesis and chemical synthesis." Proceedings of the National Academy of Sciences 117, no. 9 (February 12, 2020): 5074–80. http://dx.doi.org/10.1073/pnas.1913463117.
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Integration of electroactive bacteria into electrodes combines strengths of intracellular biochemistry with electrochemistry for energy conversion and chemical synthesis. However, such biohybrid systems are often plagued with suboptimal electrodes, which limits the incorporation and productivity of the bacterial colony. Here, we show that an inverse opal-indium tin oxide electrode hosts a large population of current-producingGeobacterand attains a current density of 3 mA cm−2stemming from bacterial respiration. Differential gene expression analysis revealedGeobacter’s transcriptional regulations to express more electron-relaying proteins when interfaced with electrodes. The electrode also allows coculturing withShewanellafor syntrophic electrogenesis, which grants the system additional flexibility in converting electron donors. The biohybrid electrode containingGeobactercan also catalyze the reduction of soluble fumarate and heterogenous graphene oxide, with electrons from an external power source or an irradiated photoanode. This biohybrid electrode represents a platform to employ live cells for sustainable power generation and biosynthesis.
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Hasan, Kamrul, Sunil A. Patil, Dónal Leech, Cecilia Hägerhäll, and Lo Gorton. "Electrochemical communication between microbial cells and electrodes via osmium redox systems." Biochemical Society Transactions 40, no. 6 (November 21, 2012): 1330–35. http://dx.doi.org/10.1042/bst20120120.
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Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.
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Buzzetti, Paulo Henrique M., Pierre-Yves Blanchard, Emerson Marcelo Girotto, Yuta Nishina, Serge Cosnier, Alan Le Goff, and Michael Holzinger. "Insights into carbon nanotube-assisted electro-oxidation of polycyclic aromatic hydrocarbons for mediated bioelectrocatalysis." Chemical Communications 57, no. 71 (2021): 8957–60. http://dx.doi.org/10.1039/d1cc02958d.
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Polyaromatic hydrocarbons were electro-oxidized on CNT electrodes and studied towards their capacity to transfer electrons from the enzyme FAD-GDH to the electrode. A mixture of electro-oxidized pyrene and pyrene NHS gave high performing biocathodes.
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Kuang, Peijing, Yubo Cui, Chuanping Feng, and Yasuaki Einaga. "Study of nitrate contaminants removal from groundwater on copper modified BDD electrode." E3S Web of Conferences 194 (2020): 04024. http://dx.doi.org/10.1051/e3sconf/202019404024.
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The electrochemical nitrate reduction by using boron-doped diamond (BDD) and copper modified boron-doped diamond (Cu-BDD) electrodes was investigated at various potentials. Nitrate reduction efficiency and the products distribution was strongly dependent on the applied potential for both electrodes. The highest nitrate reduction efficiency of 77% was obtained at −2.0 V (vs. Ag/AgCl) by using Cu-BDD. Compared with BDD electrode, nitrate reduction on Cu-BDD electrode occurred at more positive potential. Copper oxides formed on BDD surface efficiently promoted enhanced conductivity of electrode to promote electrons transfer during nitrate reduction process. Meanwhile, the catalytic ability of copper was also conductive to the nitrate transformation. Therefore, the developed Cu-BDD would be a promising approach for efficient nitrate removal from groundwater.
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Liu, Guan-Yu, Wei-Feng Sun, and Qing-Quan Lei. "Charge Injection and Dielectric Characteristics of Polyethylene Terephthalate Based on Semiconductor Electrodes." Materials 14, no. 6 (March 10, 2021): 1344. http://dx.doi.org/10.3390/ma14061344.
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Employing a novel semiconductor electrode in comparison with the traditional semiconductor electrode made of polyethylene/ethylene-vinyl-acetate copolymer/carbon-black (PE/EVA/CB) composite, characteristic charge carriers are injected into polyethylene terephthalate (PET) as a polymer dielectric paradigm, which will be captured by specific deep traps of electrons and holes. Combined with thermal stimulation current (TSC) experiments and first-principles electronic-state calculations, the injected charges from the novel electrode are characterized, and the corresponding dielectric behavior is elucidated through DC conductance, electrical breakdown and dielectric spectrum tests. TSC experiments with novel and traditional semiconductor electrodes can distinguish the trapping characteristics between hole and electron traps in polymer dielectrics. The observable discrepancy in space charge-limited conductance and the stable dielectric breakdown strength demonstrate that the electron injection into PET film specimen is restricted by using the novel semiconductor electrode. Attributed to the favorable suppression on the inevitable electron injections from metal electrodes, adopting novel i-electrode can avoid the evident abatement of dipole orientation polarization caused by space charge clamp, but will engender the accessional high-frequency dielectric loss from dielectric relaxations of interface charges at i-electrodes.
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Medhisuwakul, M., Thiraphat Vilaithong, and Jürgen Engemann. "A New Design and Computer Simulation of a 5-Electrode Ion Extraction/Focusing System." Solid State Phenomena 107 (October 2005): 21–24. http://dx.doi.org/10.4028/www.scientific.net/ssp.107.21.
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A 13.56 MHz radio-frequency (rf) driven multicusp ion source has been constructed [1] to produce a high argon ion current density. Milliampere-range argon ion current can be extracted from the source. An in-waveguide microwave plasma source has been utilized as the ion beam neutralizer [2]. The neutralization source was placed 20 cm downstream from the extraction system. With the former extraction system, comprised of extraction electrodes and an Einzel lens, the electrons from the neutralizer were attracted to the high positive potential of the lens. Consequently, the potential of the lens drops and the beam is diverged. To suppress electrons from being accelerated to the Einzel lens a negatively biased electrode was placed before the last electrode, which is grounded, to produce a retarding electric field for electrons. The hole of the electrode was made small to make sure that the potential at the center is negative enough to suppress electrons. All simulations have been performed with the KOBRA3-INP simulation software. The results of the beam shape from the simulation will be presented.
8
Strycharz, Sarah M., Trevor L. Woodard, Jessica P. Johnson, Kelly P. Nevin, Robert A. Sanford, Frank E. L�ffler, and Derek R. Lovley. "Graphite Electrode as a Sole Electron Donor for Reductive Dechlorination of Tetrachlorethene by Geobacter lovleyi." Applied and Environmental Microbiology 74, no. 19 (July 25, 2008): 5943–47. http://dx.doi.org/10.1128/aem.00961-08.
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ABSTRACT The possibility that graphite electrodes can serve as the direct electron donor for microbially catalyzed reductive dechlorination was investigated with Geobacter lovleyi. In an initial evaluation of whether G. lovleyi could interact electronically with graphite electrodes, cells were provided with acetate as the electron donor and an electrode as the sole electron acceptor. Current was produced at levels that were ca. 10-fold lower than those previously reported for Geobacter sulfurreducens under similar conditions, and G. lovleyi anode biofilms were correspondingly thinner. When an electrode poised at −300 mV (versus a standard hydrogen electrode) was provided as the electron donor, G. lovleyi effectively reduced fumarate to succinate. The stoichiometry of electrons consumed to succinate produced was 2:1, the ratio expected if the electrode served as the sole electron donor for fumarate reduction. G. lovleyi effectively reduced tetrachloroethene (PCE) to cis-dichloroethene with a poised electrode as the sole electron donor at rates comparable to those obtained when acetate serves as the electron donor. Cells were less abundant on the electrodes when the electrodes served as an electron donor than when they served as an electron acceptor. PCE was not reduced in controls without cells or when the current supply to cells was interrupted. These results demonstrate that G. lovleyi can use a poised electrode as a direct electron donor for reductive dechlorination of PCE. The ability to colocalize dechlorinating microorganisms with electrodes has several potential advantages for bioremediation of subsurface chlorinated contaminants, especially in source zones where electron donor delivery is challenging and often limits dechlorination.
9
Suciyati, Sri Wahyu, Gurum Ahmad Pauzi, Junaidi Junaidi, and L. Kamalia. "Proteksi Katodik pada Elektrode Zn Metode Sacrificial Anode untuk Peningkatan Kinerja Sistem Akumulator Air Laut." Jurnal Teori dan Aplikasi Fisika 8, no. 2 (July 31, 2020): 127–34. http://dx.doi.org/10.23960/jtaf.v8i2.2557.
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Corrosion to the Zn electrode in the seawater accumulator system can be controlled by the cathodic protection of the sacrificial anode system. The mechanism is via anode sacrifice such as Al which has a negative potential connected to the Zn structure to provide extra electrons. The Zn electrode design is protected by an Al offering anode to form Cu-ZnAl electrode pairs arranged in series to form a seawater accumulator. Testing of electrodes with sacrificial anode system cathodic protection (Cu-ZnAl) compared to unprotected electrodes (Cu-Zn) for 48 hours showed no-load voltages of 10.19 V (Cu-Zn) and 12.89 V while the power generated was 48.36 mW and 49.37 mW. The average power after 3 watt LED loading was obtained 12.03 mW (day 1) and 12.56 mW (day 2) for the Cu-ZnAl electrode, while the Cu-Zn electrode obtained an average power of 6, 68 mW (day 1) and 10.09 mW (day 2). The corrosion rates after two days of using the Cu-Zn and Cu-ZnAl electrode pairs were obtained 0.008136 mm/year (Zn) and 0.0749626 mm/year (ZnAl).
10
Gnapowski, Sebastian, Elżbieta Kalinowska-Ozgowicz, Mariusz Śniadkowski, and Aleksandra Pietraszek. "Investigation of the Condition of the Gold Electrodes Surface in a Plasma Reactor." Materials 12, no. 13 (July 3, 2019): 2137. http://dx.doi.org/10.3390/ma12132137.
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During the long-term operation of a plasma reactor, decreases in plasma concentration were noticed despite the constant maintenance of all parameters. One of the factors was the decrease in the nitrogen content on the electrode surface; in order to eliminate it, the supply voltage was increased up to 11 kV. Another decisive factor in the plasma concentration decrease was the oxidation of the electrode surface. These effects were studied using two electrodes: a gold one and a copper one coated with a 10 μm thick layer of galvanized gold. In the experiment with the gold coated electrode, a large decrease in plasma concentration was observed. High-energy electrons knocked out the gold atoms from the electrode; as a result, the gold atoms evaporated and the raids layers formed. After the electrodes had been in operation for a month, metallographic analyzes were carried out, the results of which are described in this paper.
11
Alekseenko, Kira, and Valentina N. Batalova. "Study of Phenol Oxidation Products over Glassy Carbon Electrode in Alkaline Solutions by Photoluminescence Spectroscopy." Advanced Materials Research 1085 (February 2015): 23–28. http://dx.doi.org/10.4028/www.scientific.net/amr.1085.23.
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In this research, a new approach is used to identify the products of electrochemical oxidation of UV visible substances over solid electrodes. In order to determine the product of phenol electrooxidation over glassy carbon electrode, the results obtained using voltammetric method and photoluminescence spectroscopy have been compared. It was proved that in an alkaline solution phenol is present in form of phenolate-ion, adsorbing on the surface of glassy carbon electrode, and oxidized to hydroquinone with transfer of two electrons.
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Malki, Moustafa, Antonio L. De Lacey, Nuria Rodríguez, Ricardo Amils, and Victor M. Fernandez. "Preferential Use of an Anode as an Electron Acceptor by an Acidophilic Bacterium in the Presence of Oxygen." Applied and Environmental Microbiology 74, no. 14 (May 16, 2008): 4472–76. http://dx.doi.org/10.1128/aem.00209-08.
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ABSTRACT Several anaerobic metal-reducing bacteria have been shown to be able to donate electrons directly to an electrode. This property is of great interest for microbial fuel cell development. To date, microbial fuel cell design requires avoiding O2 diffusion from the cathodic compartment to the sensitive anodic compartment. Here, we show that Acidiphilium sp. strain 3.2 Sup 5 cells that were isolated from an extreme acidic environment are able to colonize graphite felt electrodes. These bacterial electrodes were able to produce high-density electrocatalytic currents, up to 3 A/m2 at a poised potential of +0.15 V (compared to the value for the reference standard calomel electrode) in the absence of redox mediators, by oxidizing glucose even at saturating air concentrations and very low pHs.
13
Marugán, Javier, Rafael van Grieken, Cristina Pablos, Cristina Adán, and Ruud Timmers. "Determination of Photochemical, Electrochemical and Photoelectrochemical Efficiencies in a Photoelectrocatalytic Reactor." International Journal of Chemical Reactor Engineering 11, no. 2 (June 20, 2013): 787–97. http://dx.doi.org/10.1515/ijcre-2012-0014.
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Abstract The relation between the amount of incident photons, absorbed photons, oxidant species, reaction products and electrons in the external circuit should be analyzed individually to determine the step limiting the efficiency of the global photoelectrocatalytic processes. This work discusses the evaluation of three different titania electrodes for the oxidation of methanol in a photoelectrocatalytic reactor. The electrode prepared with three titania coating cycles shows a high efficiency in terms of photochemical (photons to product molecules), electrochemical (product molecules to electrons) and photoelectrochemical (photons to electrons) what explain its high activity for the photoelectrocatalytic oxidation of methanol.
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Yuangkaew, Tienthong, Chotiros Prasansaeng, Papot Jaroenapibal, and Napat Triroj. "Investigation of Photoelectrochemical Parameters of Electrospun TiO2 Nanofiber Electrode." Advanced Materials Research 931-932 (May 2014): 266–70. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.266.
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This work reports the fabrication and photoelectrochemical response of titanium dioxide (TiO2) nanofiber photoelectrode prepared by an electrospinning technique. Transmission electron microscopy (TEM) images reveal that the electropun nanofibers are composed of TiO2 nanoparticles with the average diameter size of 25 nm. The scanning electron microscopy (SEM) image of the photoelectrode confirms the existence of TiO2 nanofiber networks on Ti/Si substrate after the electrode preparation using a doctor-blade technique. The photoelectrochemical performance of TiO2 nanofiber electrode is investigated in comparison with that of TiO2 (Aeroxide P25) nanoparticle electrode. When the TiO2 electrodes are subjected to light illumination at 100 mW/cm2, the maximum photoconversion efficiency (PCE) of 0.95% is obtained at the TiO2 nanofiber electrode while reduced PCE of 0.75% is obtained at the TiO2 nanoparticle electrode.
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Davydova, Marina, Pavel Kulha, Alexandr Laposa, Karel Hruska, Pavel Demo, and Alexander Kromka. "Gas sensing properties of nanocrystalline diamond at room temperature." Beilstein Journal of Nanotechnology 5 (December 4, 2014): 2339–45. http://dx.doi.org/10.3762/bjnano.5.243.
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This study describes an integrated NH3 sensor based on a hydrogenated nanocrystalline diamond (NCD)-sensitive layer coated on an interdigitated electrode structure. The gas sensing properties of the sensor structure were examined using a reducing gas (NH3) at room temperature and were found to be dependent on the electrode arrangement. A pronounced response of the sensor, which was comprised of dense electrode arrays (of 50 µm separation distance), was observed. The sensor functionality was explained by the surface transfer doping effect. Moreover, the three-dimensional model of the current density distribution of the hydrogenated NCD describes the transient flow of electrons between interdigitated electrodes and the hydrogenated NCD surface, that is, the formation of a closed current loop.
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Matsunaga, Yuki, and Takahide Oya. "Development of Paint-Type Dye-Sensitized Solar Cell Using Carbon Nanotube Paint." Journal of Nanotechnology 2019 (April 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/5081034.
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This paper proposes paint-type dye-sensitized solar cells (DSCs). DSCs, one type of solar cell, generally consist of a dye-attached semiconducting electrode, a metallic electrode, and an electrolyte. The DSC generates power through the excitation of the electrons in the dyes and the oxidation-reduction reaction between the dyes and the electrolyte. For our paint-type DSC, we made two electrodes by painting two types of paint on substrates. We used carbon nanotubes (CNTs) as the paint material because they have both semiconducting and metallic properties. This enabled us to prepare semiconducting and metallic electrodes easily by simply painting with the CNT paint. As a result of testing, we determined that our DSCs were capable of power generation. Our paint-type DSCs have the potential to provide power as a unique and useful device for daily life in the near future.
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Stenzel, Reiner L., Johannes Grünwald, Codrina Ionita, Roman Schrittwieser, and Manuel Urrutia. "Sheaths and Double Layers with Instabilities." Journal of Technological and Space Plasmas 2, no. 1 (March 24, 2021): 70–92. http://dx.doi.org/10.31281/jtsp.v2i1.16.
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The properties of sheaths and associated potential structures and instabilities cover a broad field which even a review cannot cover everything. Thus, the focus will be on about a dozen examples, describe their observations and focus on the basic physical explanations for the effects, while further details are found in the references. Due to familiarity the review focuses mainly on the authors work but compared and referenced related work. The topics start with a high frequency oscillations near the electron plasma frequency. Low frequency instabilities also occur at the ion plasma frequency.The injection of ions into an electron-rich sheath widens the sheath and forms a double layer. Likewise, the injection of electrons into an ion rich sheath widens and establishes a double layer which occurs in free plasma injection into vacuum. The sheath widens and forms a double layer by ionization in an electron rich sheath. When particle fluxes in "fireballs" gets out of balance the double layer performs relaxation instabilities which has been studied extensively. Fireballs inside spherical electrodes create a new instability due to the transit time of trapped electrons. On cylindrical and spherical electrodes the electron rich sheath rotates in magnetized plasmas. Electrons rotate due to $\mathbf E \times \mathbf B_0$ which excites electron drift waves with azimuthal eigenmodes. Conversely a permanent magnetic dipole has been used as a negative electrode. The impact of energetic ions produces secondary electron emission, forming a ring of plasma around the magnetic equator. Such "magnetrons" are subject to various instabilities. Finally, the current to a positively biased electrode in a uniformly magnetized plasma is unstable to relaxation oscillations, which shows an example of global effects. The sheath at the electrode raises the potential in the flux tube of the electrode thereby creating a radial sheath which moves unmagnetized ions radially. The ion motion creates a density perturbation which affects the electrode current. If the electrode draws large currents the current disruptions create large inductive voltages on the electrode, which again produce double layers. This phenomenon has been seen in reconnection currents. Many examples of sheath properties will be explained. Although the focus is on the physics some examples of applications will be suggested such as neutral gas heating and accelerating, sputtering of plasma magnetrons and rf oscillators.
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Kim, Eunhwan, Juyeon Han, Seokgyu Ryu, Youngkyu Choi, and Jeeyoung Yoo. "Ionic Liquid Electrolytes for Electrochemical Energy Storage Devices." Materials 14, no. 14 (July 16, 2021): 4000. http://dx.doi.org/10.3390/ma14144000.
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For decades, improvements in electrolytes and electrodes have driven the development of electrochemical energy storage devices. Generally, electrodes and electrolytes should not be developed separately due to the importance of the interaction at their interface. The energy storage ability and safety of energy storage devices are in fact determined by the arrangement of ions and electrons between the electrode and the electrolyte. In this paper, the physicochemical and electrochemical properties of lithium-ion batteries and supercapacitors using ionic liquids (ILs) as an electrolyte are reviewed. Additionally, the energy storage device ILs developed over the last decade are introduced.
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Ma, Chun An, Nan Nan You, and Li Mei Chao. "Studies on Electrochemical Dechlorination Reaction of 2,4-Dichlorobenzoic Acid on Pd/Ti Electrode." Advanced Materials Research 356-360 (October 2011): 178–81. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.178.
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Abstract: Pd/Ti electrode was prepared on Ti substrate electrode in hydrochloric acid containing PdCl2 using cyclic voltammetry. The electrocatalytic performance toward electrochemical reduction reactivity of 2,4-dichlorobenzoic acid (2,4-DCBA) on Cu, Ag, Ti and Pd/Ti was investigated. Compared with Cu, Ag and Ti electrodes, Pd/Ti electrode exhibited a high electrochemical activity for the reduction process of 2,4-DCBA in NaOH solution. In situ FTIR was applied to analyze the electrochemical dechlorination mechanism of 2,4-DCBA systematically. The results showed that 2,4-DCBA was electroreduced to its free radical ion after receiving an electron. Then the 2,4-DCBA free radical took off two chloride ions and produced the benzoic acid free radical. After receiving another two electrons and two protons, the final product benzoic acid was obtained.
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Hong, Hyeonaug, Jang Mee Lee, JaeHyoung Yun, Yong Jae Kim, Seon Il Kim, HyeIn Shin, Hyun S. Ahn, Seong-Ju Hwang, and WonHyoung Ryu. "Enhanced interfacial electron transfer between thylakoids and RuO2 nanosheets for photosynthetic energy harvesting." Science Advances 7, no. 20 (May 2021): eabf2543. http://dx.doi.org/10.1126/sciadv.abf2543.
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The harvesting of photosynthetic electrons (PEs) directly from photosynthetic complexes has been demonstrated over the past decade. However, their limited efficiency and stability have hampered further practical development. For example, despite its importance, the interfacial electron transfer between the photosynthetic apparatus and the electrode has received little attention. In this study, we modified electrodes with RuO2 nanosheets to enhance the extraction of PEs from thylakoids, and the PE transfer was promoted by proton adsorption and surface polarity characteristics. The adsorbed protons maintained the potential of an electrode more positive, and the surface polarity enhanced thylakoid attachment to the electrode in addition to promoting ensemble docking between the redox species and the electrode. The RuO2 bioanode exhibited a five times larger current density and a four times larger power density than the Au bioanode. Last, the electric calculators were successfully powered by photosynthetic energy using a RuO2 bioanode.
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Zhang, Huijie, Rosa Catania, and Lars J. C. Jeuken. "Membrane Protein Modified Electrodes in Bioelectrocatalysis." Catalysts 10, no. 12 (December 6, 2020): 1427. http://dx.doi.org/10.3390/catal10121427.
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Transmembrane proteins involved in metabolic redox reactions and photosynthesis catalyse a plethora of key energy-conversion processes and are thus of great interest for bioelectrocatalysis-based applications. The development of membrane protein modified electrodes has made it possible to efficiently exchange electrons between proteins and electrodes, allowing mechanistic studies and potentially applications in biofuels generation and energy conversion. Here, we summarise the most common electrode modification and their characterisation techniques for membrane proteins involved in biofuels conversion and semi-artificial photosynthesis. We discuss the challenges of applications of membrane protein modified electrodes for bioelectrocatalysis and comment on emerging methods and future directions, including recent advances in membrane protein reconstitution strategies and the development of microbial electrosynthesis and whole-cell semi-artificial photosynthesis.
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Polat, Kamran, Mustafa Uçar, M. Levent Aksu, and Hüseyin Ünver. "Electrochemical behaviour of 1-{[(3-halophenyl)imino]methyl}-2-naphthol Schiff bases on graphite electrodes." Canadian Journal of Chemistry 82, no. 7 (July 1, 2004): 1150–56. http://dx.doi.org/10.1139/v04-021.
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An electrochemical study of the reduction of 1-{[(3-halophenyl)imino]methyl}-2-naphthol compounds on graphite electrodes was carried out. All the compounds were dissolved in a 1:4 (volume fraction) mixture of tetrahydrofuran (THF) and methanol. NaClO4 (0.1 mol L1) was used as the supporting electrolyte. Cyclic voltammetry, chronoamperometry, constant-potential coulometry (bulk electrolysis), and constant-potential preparative electrolysis were employed. The cyclic voltammetric data revealed that the reduction on graphite was irreversible and followed an EC mechanism. The diffusion coefficients and the number of electrons transferred were determined using the chronoamperometric Cottrell slope and the ultramicro electrode steady-state current. The number of electrons was also determined by bulk electrolysis. The products of the electroreduction were synthesized in milligram quantities by the use of constant-potential preparative electrolysis. These products were purified and characterized by spectroscopic methods. Based on these findings, a mechanism for the electroreduction process is proposed.Key words: electrochemical reduction, hydroxynaphthylideneaniline Schiff bases, cyclic voltammetry, ultramicro electrode.
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HERTSYK, Oksana, Myroslava KOVBUZ, Tetiana HULA, and Nataliia PANDIAK. "ELECTROCATALYSIS INVOLVING AMORPHOUS METAL ELECTRODES." Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2020, no. 60 (February 25, 2020): 118–26. http://dx.doi.org/10.37827/ntsh.chem.2020.60.118.
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The effect of chemical composition of amorphous metal electrodes with different elemental composition (i.e. Al87.0Y5.0Ni8.0, Fe80.0Si6.0B14.0, Fe78,5Ni1.0Mo0.5Si6.0B14.0, Fe81,0Ni1.0Nb0.5Mo0.5Si3.0B14.0, Fe73,1Cu1.0Nb3.0Si15.5B7.4) on their electrocatalytic activity in the reactions of the decomposition of peroxide –O–O– bonds in hydrogen peroxide H2O2 and organic oligoperoxide compounds based on vinyl acetate, 2-tert-butyl peroxy-2-methyl-5-hexen-3-yne and maleic anhydride was studied. The electrochemical reduction of H2O2 and organic oligoperoxsde on AMA-electrodes by cyclic voltammetry is investigated. The dependencies of the rate of electrocatalytic processes on the concentration of supporting electrolyte, the rate of scanning of potential, the concentration of depolarizer and the duration of the initial spontaneous (in the absence of external potential) interaction of the peroxides compounds with the electrode surface were investigated. The rate constants of the decomposition of –O–O– bonds in peroxides of different structure were determined. In the case of the electrocatalytic AMA electrode Al87.0Y5.0Ni8.0, the process of dissociation of –O–O– bonding by the reductive mechanism is the most probable: In the case of AMA electrodes based on Fe (especially Fe73,1Cu1.0Nb3.0Si15.5B7.4) the decomposition of –O–O– bonds follows preferential oxidation mechanism: . Due to their high absorption ability, oligoperoxide molecules can undergo conformational changes on the surface of the electrode. This affects the stability of the peroxide bond significantly. The functional groups of oligoperxides show affinity to localized electrons on the electrode surface. This leads to the elongation of the –O–O– bond and facilitates the fragmentation of the oligomers. The amorphous alloys Fe73,1Cu1.0Nb3.0Si15.5B7.4 and Fe81,0Ni1.0Nb0.5Mo0.5Si3.0B14.0 have a higher catalytical activity in decomposition of H2O2.
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Cen, Chao, and Xinhua Chen. "The Electrode Modality Development in Pulsed Electric Field Treatment Facilitates Biocellular Mechanism Study and Improves Cancer Ablation Efficacy." Journal of Healthcare Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/3624613.
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Pulsed electric field treatment is now widely used in diverse biological and medical applications: gene delivery, electrochemotherapy, and cancer therapy. This minimally invasive technique has several advantages over traditional ablation techniques, such as nonthermal elimination and blood vessel spare effect. Different electrodes are subsequently developed for a specific treatment purpose. Here, we provide a systematic review of electrode modality development in pulsed electric field treatment. For electrodes invented for experiment in vitro, sheet electrode and electrode cuvette, electrodes with high-speed fluorescence imaging system, electrodes with patch-clamp, and electrodes with confocal laser scanning microscopy are introduced. For electrodes invented for experiment in vivo, monopolar electrodes, five-needle array electrodes, single-needle bipolar electrode, parallel plate electrodes, and suction electrode are introduced. The pulsed electric field provides a promising treatment for cancer.
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Kumar, Amit, Krishna Katuri, Piet Lens, and Dónal Leech. "Does bioelectrochemical cell configuration and anode potential affect biofilm response?" Biochemical Society Transactions 40, no. 6 (November 21, 2012): 1308–14. http://dx.doi.org/10.1042/bst20120130.
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Electrochemical gradients are the backbone of basic cellular functions, including chemo-osmotic transport and ATP synthesis. Microbial growth, terminal respiratory proteins and external electron transfer are major pathways competing for electrons. In BESs (bioelectrochemical systems), such as MFCs (microbial fuel cells), the electron flow can be via soluble inorganic/organic molecules or to a solid surface. The flow of electrons towards a solid surface can be via outer-membrane cytochromes or electron-shuttle molecules, mediated by conductive protein nanowires or extracellular matrices. In MECs (microbial electrolysis cells), the anode potential can vary over a wide range, which alters the thermodynamic energy available for bacteria capable of donating electrons to the electrode [termed EAB (electroactive bacteria)]. Thus the anode potential is an important electrochemical parameter determining the growth, electron distribution/transfer and electrical activity of films of these bacteria on electrodes. Different optimal applied potentials to anodes have been suggested in the literature, for selection for microbial growth, diversity and performance in biofilms on electrodes. In the present paper, we review the effects of anode potentials on electron-transfer properties of such biofilms, and report on the effect that electrochemical cell configuration may have on performance.
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Karnik, Madhuri, Amitabha Ghosh, and Rajiv Shekhar. "The Mechanism of Electrochemical Discharge (ECD)." Key Engineering Materials 572 (September 2013): 295–99. http://dx.doi.org/10.4028/www.scientific.net/kem.572.295.
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The paper proposes mechanism of electrochemical discharge ECD based on the results of experiments in stagnant electrolyte cell (SEC). The experiments conducted in SEC have demonstrated that the physical characteristics of ECD, instantaneous current wave form (ICWF) in the cell at the time of discharge and voltage gradient developed near the tip of the discharging electrode are polarity dependant. It has been also observed that the formation of gas-vapour sheath round the tip of electrode is the benchmark leading to the discharge. Hence, an attempt has been made to suggest the polarity dependant ionization processes that can take place in the gas-vapour sheath near the discharging electrode, assuming that the ionic processes taking place at the electrodes in an electrochemical cell do not change at the time of discharge. The emission of electrons can take place from the surface of cathode due to either the field emission or thermionic emission (since the temperature of cathode shoots up in the film boiling regime) or by positive ion impact. The field ionization of gas molecules in the sheath formed around the anode tip can take place leading to tunneling of electrons from neutral gas molecules under the action of high electric field (2-51010V/m) [1] into the surface of the anode.
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Saddique, Jaffer, Xiaopeng Cheng, Huifeng Shi, Rui Wu, and Yuefei Zhang. "High-Performance Ni-Co Sulfide Nanosheet-Nanotubes Grown on Ni Foam as a Binder Free Electrode for Supercapacitors." Applied Sciences 9, no. 15 (July 31, 2019): 3082. http://dx.doi.org/10.3390/app9153082.
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The novel hierarchical Ni-Co sulfide nanosheet-nanotubes arrays were directly grown on Ni foam, as binder-free electrodes, have been successfully synthesized following a one-step facile hydrothermal method combined with a sulfide treatment. The initial value of the area capacitance achieved 2.28 F cm−2 at a current density of 1 mA cm−2. A high areal capacitance retention of 95.2% compared to activation-induced peak value is achieved after 3000 charge-discharge cycles, which is much better than counter Ni-Co oxide electrode (1.75 F cm−2 at 1 mA cm−2, 93.2% retention compared to activation induced peak value). The outstanding and excellent super capacitive performance is ascribed to ion-exchange reaction, which induces a flexible hollow nanotube feature and show higher conductivity, compared with Ni-Co oxide NWs. Cyclic voltammetry (CV) and Electrochemical impedance spectra (EIS) results confirmed that the synthesized electrode contains the lowest resistance at high, and at lower frequency, leading to easy penetration of electrolytes and fast transportation of electrons inside the electrode. In this proposed work, a one-step hydrothermal method has been followed, and provided for the sulfide-induced, with a noticeable electrochemical performance of nickel cobaltite compounds and supplying a promising route for high-performance supercapacitor electrodes.
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Shi, Zhaoliang, Wei Zhou, and Yiran Ma. "Nickel nanocrystals grown on sparse hierarchical CuS microflowers as high-performance counter electrodes for dye-sensitized solar cells." Functional Materials Letters 09, no. 05 (October 2016): 1650056. http://dx.doi.org/10.1142/s1793604716500569.
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Three kinds of hierarchical CuS microflowers composed of thin nanosheets have been synthesized by a simple wet chemical method. It is shown that the CuS microflowers provide suitable substrates to grow nickel nanocrystals. The prepared Ni@CuS hybrids combined with conductive glass (FTO) have been used as counter electrodes for dye-sensitized solar cells (DSSCs). The electrode made of the active material of Ni@CuS microflowers with sparsest petals show an optimal photoelectric conversion efficiency of 4.89%, better than those made of single component of Ni (3.39%) or CuS (1.65%), and other two Ni@CuS composites. The improved performances could be ascribed to the synergetic effect of the catalytic effect towards I[Formula: see text]/I[Formula: see text] from sparse CuS hierarchical structure and uniformly grown Ni nanocrystals. Besides, the introduced Ni nanocrystals could increase the conductivity of the hybrid and facilitate the transport of electrons. The hybrid Ni@CuS composites serving as counter electrodes have much enhanced electrochemical properties, which provide a feasible route to develop high-active non-noble hybrid counter electrode materials.
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ZHANG, C. "EFFECT OF INELASTIC SCATTERING OF HOT ELECTRONS ON THERMIONIC COOLING IN A SINGLE-BARRIER STRUCTURE." International Journal of Modern Physics B 14, no. 14 (June 10, 2000): 1451–57. http://dx.doi.org/10.1142/s0217979200001503.
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One of the important problems in thermionics using layered structures is the inelastic scattering of hot electrons in the electrodes and in the barrier region. Scattering in these systems is mainly via the electron–phonon interaction, or indirectly via the electron–electron interaction. In semiconductor heterostructures at room temperature, the LO-phonon plays a crucial role in thermalising electrons. In this work we study the effect of electron–phonon scattering on thermionic cooling in a single-barrier structure. Because of the asymmetry of the barrier under a bias, a larger fraction of the total energy loss will be dissipated in the hot electrode. As a result, we find that the theoretical thermal efficiency can increase due to limited electron–phonon scattering.
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Canales, Camila, Leyla Gidi, Roxana Arce, Francisco Armijo, María Aguirre, and Galo Ramírez. "Electro-Reduction of Molecular Oxygen Mediated by a Cobalt(II)octaethylporphyrin System onto Oxidized Glassy Carbon/Oxidized Graphene Substrate." Catalysts 8, no. 12 (December 6, 2018): 629. http://dx.doi.org/10.3390/catal8120629.
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The oxygen reduction reaction (ORR) is the most important reaction in life processes and in energy transformation. The following work presents the design of a new electrode which is composed by deposited cobalt octaethylporphyrin onto glassy carbon and graphene, where both carbonaceous materials have been electrochemically oxidized prior to the porphyrin deposition. The novel generated system is stable and has an electrocatalytic effect towards the oxygen reduction reaction, as a result of the significant overpotential shift in comparison to the unmodified electrode and to the electrodes used as target. Kinetic studies corroborate that the system is capable of reducing molecular oxygen via four electrons, with a Tafel slope value of 60 mV per decade. The systems were morphologically characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) Electrochemical impedance spectroscopy studies showed that the electrode previously oxidized and modified with cobalt porphyrin is the system that possesses lower resistance to charge transfer and higher capacitance.
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Shen, Jia Nian, Mou Cheng Li, Dong Liu, Xian Rong Sun, Ekoko Bakambo Gracien, Shu Dian Yao, and Bin Wan. "Effects of Applied Bias and Dopants on the Photocatalytic Degradation of Aqueous Dye Solution by TiO2/Ti Electrode." Materials Science Forum 539-543 (March 2007): 2240–45. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.2240.
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The photocatalytic degradation of organics in aqueous solution is an active research field. Currently, the relatively low degradation efficiency is the key problem to be solved that caused by the simple recombination of the photo-generated electrons and holes. The electrode was prepared by anodic oxidation on titanium thin plate and produced multiporous nano-crystalline titanium dioxide film with anatase structure on titanium substrate. In order to inhibit the simple recombination of the electrons and holes, the electric potential bias was applied to the electrode to drive away the chargers. The change of the photocurrent and the discolouration of the dye solution containing either methylene blue or acid red G with different magnitude of the applied bias were measured. It shows that the photocurrent increased by three orders of magnitude from μA to mA level by the applied bias. Correspondingly, the discolouration rate of the methylene blue in dye solution was increased greatly with the increasing applied bias up to 3.5V. The different kinds of transitional metal ions dopants of Mn2+, Cr3+, Fe3+, and Ni2+ to the electrodes was done by anodic oxidation method. The effects of different types of dopants on the photocatalytic activity were revealed by measuring the degradation of an organics aqueous solution containing a dye using a combination of ultraviolet light energy in the presence of these electrodes. The photocatalytic efficiency, which was remarkably enhanced by the incorporation of Mn2+、 Cr3+.、 Mn2+, showed the largest enhancement. However, Fe3+ changed only slightly, and Ni2+ showed no enhancement. These effects were related to the difference of these transitional metal dopants electron work function values and also to the difference of their ionic radii in respect to that of Ti4+. The configuration of the reactor for water treatment with the rotating electrode and 365nm wavelength UV radiation was described.
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Zhang, Wenguang, Xuele Yin, and Xuhui Zhou. "Optimal design and evaluation of a multi-shank structure based neural probe." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 1373–80. http://dx.doi.org/10.3233/jae-209456.
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In order to develop long-lifetime neural electrodes, the insertion tissue injury caused by two optimized neural electrode (convex streamline electrode and vibration attenuation electrode) models were evaluated compared with a reference electrode. Based on the experimental evaluation system for testing tissue injury, the effects of insertion speeds on tissue injury of the two optimized electrodes with different insertion depths were studied. The maximum tissue strain caused by the two optimized neural electrodes firstly increased and then decreased with the increase of insertion speed at the depths of 3 mm and 4.5 mm. The insertion forces caused by vibration attenuation electrode are steady with the change of insertion speed. The convex streamline neural electrode caused less tissue injury compared with the other two electrodes. The higher or lower insertion speed causes smaller tissue strain for the two optimized electrodes, which is conductive to set implantation parameters to minimize tissue injury.
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Zhang, Wenguang, Xuele Yin, Jie Xie, Yakun Ma, and Zhengwei Li. "Experimental evaluation of optimal-designed neural electrodes based on simulated implantation system." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 1401–9. http://dx.doi.org/10.3233/jae-209459.
Full textAbstract:
In order to develop long-lifetime neural electrodes, the insertion tissue injury caused by two optimized neural electrode (convex streamline electrode and vibration attenuation electrode) models were evaluated compared with a reference electrode. Based on the experimental evaluation system for testing tissue injury, the effects of insertion speeds on tissue injury of the two optimized electrodes with different insertion depths were studied. The maximum tissue strain caused by the two optimized neural electrodes firstly increased and then decreased with the increase of insertion speed at the depths of 3 mm and 4.5 mm. The insertion forces caused by vibration attenuation electrode are steady with the change of insertion speed. The convex streamline neural electrode caused less tissue injury compared with the other two electrodes. The higher or lower insertion speed causes smaller tissue strain for the two optimized electrodes, which is conductive to set implantation parameters to minimize tissue injury.
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BASTANINEJAD, M., A. A. ELMUSTAFA, C. M. ANKENBRANDT, A. MORETTI, M. POPOVIC, K. YONEHARA, D. M. KAPLAN, et al. "STUDIES OF BREAKDOWN IN A PRESSURIZED RF CAVITY." International Journal of Modern Physics A 26, no. 10n11 (April 30, 2011): 1753–60. http://dx.doi.org/10.1142/s0217751x11053158.
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Microscopic images of the surfaces of metallic electrodes used in high-pressure gas-filled 805 MHz RF cavity experiments1 have been used to investigate the mechanism of RF breakdown.2 The images show evidence for melting and boiling in small regions of ~10 micron diameter on tungsten, molybdenum, and beryllium electrode surfaces. In these experiments, the dense hydrogen gas in the cavity prevents electrons or ions from being accelerated to high enough energy to participate in the breakdown process so that the only important variables are the fields and the metallic surfaces. The distributions of breakdown remnants on the electrode surfaces are compared to the maximum surface gradient E predicted by an ANSYS model of the cavity. The local surface density of spark remnants, proportional to the probability of breakdown, shows a strong exponential dependence on the maximum gradient, which is reminiscent of Fowler-Nordheim behavior of electron emission from a cold cathode. New simulation results have shown good agreement with the breakdown behavior of the hydrogen gas in the Paschen region and have suggested improved behavior with the addition of trace dopants such as SF 6.3 Present efforts are to extend the computer model to include electrode breakdown phenomena and to use scanning tunneling microscopy to search for work function differences between the conditioned and unconditioned parts of the electrodes.
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Stewart, IM. "The Distribution of Electrons in a Uniform Electric Field." Australian Journal of Physics 48, no. 1 (1995): 89. http://dx.doi.org/10.1071/ph950089.
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Experiments are under way at the University of New England to measure the optical absorption of excited gas particles in a pre-breakdown discharge. Such measurements can be used to deduce the number density of electrons in the discharge. By comparing this experimental density map with the predictions of theory, electron transport parameters may be determined. In this paper, new theoretical expressions are derived for the number density distributions of electrons in a uniform electric field. These are found by solving the electron diffusion equation in a plane parallel electrode geometry with a radially symmetric cathodic current source. The contribution of ion-induced secondary current is included, and problems posed by non-equilibrium conditions near the electrodes are addressed. Techniques of data reduction are discussed with a particular emphasis on the avoidance of these problems.
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Scandurra, Antonino, Francesco Ruffino, Maria Censabella, Antonio Terrasi, and Maria Grazia Grimaldi. "Dewetted Gold Nanostructures onto Exfoliated Graphene Paper as High Efficient Glucose Sensor." Nanomaterials 9, no. 12 (December 16, 2019): 1794. http://dx.doi.org/10.3390/nano9121794.
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Non-enzymatic electrochemical glucose sensing was obtained by gold nanostructures on graphene paper, produced by laser or thermal dewetting of 1.6 and 8 nm-thick Au layers, respectively. Nanosecond laser annealing produces spherical nanoparticles (AuNPs) through the molten-phase dewetting of the gold layer and simultaneous exfoliation of the graphene paper. The resulting composite electrodes were characterized by X-ray photoelectron spectroscopy, cyclic voltammetry, scanning electron microscopy, micro Raman spectroscopy and Rutherford back-scattering spectrometry. Laser dewetted electrode presents graphene nanoplatelets covered by spherical AuNPs. The sizes of AuNPs are in the range of 10–150 nm. A chemical shift in the XPS Au4f core-level of 0.25–0.3 eV suggests the occurrence of AuNPs oxidation, which are characterized by high stability under the electrochemical test. Thermal dewetting leads to electrodes characterized by faceted not oxidized gold structures. Glucose was detected in alkali media at potential of 0.15–0.17 V vs. saturated calomel electrode (SCE), in the concentration range of 2.5μM−30 mM, exploiting the peak corresponding to the oxidation of two electrons. Sensitivity of 1240 µA mM−1 cm−2, detection limit of 2.5 μM and quantifications limit of 20 μM were obtained with 8 nm gold equivalent thickness. The analytical performances are very promising and comparable to the actual state of art concerning gold based electrodes.
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Huang, Yiping, Yatong Song, Li Gou, and Yuanwen Zou. "A Novel Wearable Flexible Dry Electrode Based on Cowhide for ECG Measurement." Biosensors 11, no. 4 (April 1, 2021): 101. http://dx.doi.org/10.3390/bios11040101.
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The electrocardiogram (ECG) electrode, as a sensor, is an important part of the wearable ECG monitoring device. Natural leather is rarely used as the electrode substrate. In this paper, wearable flexible silver electrodes based on cowhide were prepared by sputtering and brush-painting. A signal generator, oscilloscope, impedance test instrument, and ECG monitor were used to build the test platform evaluating the performance of electrodes with six subjects. The lossless waveform transmission can be achieved with our electrodes. Therefore, the Pearson’s correlation coefficient calculated with input waveform and output waveform of the electrodes based on the top grain layer (GLE) and the split layer (SLE) of cowhide were 0.997 and 0.998 at 0.1 Hz respectively. The skin electrode impedance (Z) was tested, and the parameters of the equivalent circuit model of the skin electrode interface were calculated by a fitting method, indicating that the Z of the prepared electrodes was comparable with the standard gel electrode when the skin is moist enough. The signal-to-noise ratio of the ECG of the GLE and the SLE were 1.148 and 1.205 times that of the standard electrode in the standing posture, which meant the ECG measured by our electrodes was basically consistent with that measured by the standard electrode.
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Han, Qing, Ge Ming Liu, Niu Sheng Peng, Tao Feng, Jin Feng Xia, and Jin Xia. "Preparation and Characterization of Pt/YSZ Electrode of Zirconia Oxygen Sensor." Key Engineering Materials 544 (March 2013): 72–75. http://dx.doi.org/10.4028/www.scientific.net/kem.544.72.
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Electrode slurry made of Pt powder was brushed on both surfaces of the sintered ZrO2 substrate. And then the Pt electrodes were sintered under various temperatures. The microstructure of the surface of the electrodes was characterized by scanning electronic microscope. The electrochemical properties of the electrodes were investigated by electrochemical impedance spectroscopy (EIS). The results show that the sintered temperature of the electrode has a remarkable effect on the microstructure of the electrode and the Pt electrode show favorable electrochemical catalysis performance.
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Song, Jinzhong, Tianshu Zhou, Zhonggang Liang, Ruoxi Liu, Jianping Guo, Xinming Yu, Zhongping Cao, Chuang Yu, Qingjun Liu, and Jingsong Li. "Electrochemical Characteristics Based on Skin-Electrode Contact Pressure for Dry Biomedical Electrodes and the Application to Wearable ECG Signal Acquisition." Journal of Sensors 2021 (September 15, 2021): 1–9. http://dx.doi.org/10.1155/2021/7741881.
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Based on one simulated skin-electrode electrochemical interface, some electrochemical characteristics based on skin-electrode contact pressure (SECP) for dry biomedical electrodes were analysed and applied in this research. First, 14 electrochemical characteristics including 2 static impedance (SI) characteristics, 11 alternating current impedance (ACI) characteristics and one polarization voltage (PV), and 4 SECP characteristics were extracted in one electrochemical evaluation platform, and their correlation trends were statistically analysed. Second, dry biomedical electrode samples developed by the company and the laboratory, including textile electrodes, Apple watch, AMAZFIT rice health bracelet 1S, and stainless steel electrodes, were placed horizontally and vertically on the “skin” surface of the electrochemical evaluation platform, whose polarization voltages were quantitatively analysed. Third, electrocardiogram (ECG) collection circuits based on an impedance transformation (IT) circuit for textile electrodes were designed, and a wearable ECG acquisition device was designed, which could obtain complete ECG signals. Experimental results showed SECP characteristics for dry electrodes had good correlations with static impedance and ACI characteristics and the better correlation values among 2-10 Hz. In addition, polarization voltages in vertical state were smaller in horizontal state for dry biomedical electrodes, and polarization voltage of electrode pair (PVEP) values for Apple watch bottom was always smaller than ones for Apple watch crown and LMF-2 textile electrode. And the skin-electrode contact impedance of IT textile electrodes was less than the traditional textile electrodes.
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Chen, Yan, and Li Bao An. "Simulation of Electric Field for Carbon Nanotube Assembly by Dielectrophoresis." Advanced Materials Research 941-944 (June 2014): 421–24. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.421.
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In the process of carbon nanotube assembly by dielectrophoresis, the geometry and spacing of electrodes are significantly affecting the assembly precision. In the simulation process, we showed the geometrical shape of conical, round and rectangular electrode and compared the electric field distribution with these electrodes. Compared with single electrode pairs, comb electrodes can achieve high-yield manipulation. Simulation results show that when the distance between adjacent electrode pairs is larger than twice electrode width, it will avoid electric field superimposition. A method of using floating metal posts within the electrode gap can realize precise positioning of assembled carbon nanotubes.
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Jaffe, Debra M., Nancy P. Solomon, Robert A. Robinson, Henry T. Hoffman, and Erich S. Luschei. "Comparison of Concentric Needle Versus Hooked-Wire Electrodes in the Canine Larynx." Otolaryngology–Head and Neck Surgery 118, no. 5 (May 1998): 655–62. http://dx.doi.org/10.1177/019459989811800515.
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BACKGROUND: The use of a specific electrode type in laryngeal electromyography has not been standardized. Laryngeal electromyography is usually performed with hooked-wire electrodes or concentric needle electrodes. Hooked-wire electrodes have the advantage of allowing laryngeal movement with ease and comfort, whereas the concentric needle electrodes have benefits from a technical aspect and may be advanced, withdrawn, or redirected during attempts to appropriately place the electrode. OBJECTIVES: This study examines whether hooked-wire electrodes permit more stable recordings than standard concentric needle electrodes at rest and after large-scale movements of the larynx and surrounding structures. A histologic comparison of tissue injury resulting from placement and removal of the two electrode types is also made by evaluation of the vocal folds. METHODS: Electrodes were percutaneously placed into the thyroarytenoid muscles of 10 adult canines. Amplitude of electromyographic activity was measured and compared during vagal stimulation before and after large-scale laryngeal movements. Signal consistency over time was examined. Animals were killed and vocal fold injury was graded and compared histologically. RESULTS: Waveform morphology did not consistently differ between electrode types. The variability of electromyographic amplitude was greater for the hooked-wire electrode ( p < 0.05), whereas the mean amplitude measures before and after large-scale laryngeal movements did not differ ( p > 0.05). Inflammatory responses and hematoma formation were also similar. CONCLUSIONS: Waveform morphology of electromyographic signals registered from both electrode types show similar complex action potentials. There is no difference between the hooked-wire electrode and the concentric needle electrode in terms of electrode stability or vocal fold injury in the thyroarytenoid muscle after large-scale laryngeal movements. (Otolaryngol Head Neck Surg 1998;118:655–62.)
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Zhen, Shao Hua, Li Bao An, and Chun Rui Chang. "Simulation on the Dielectrophoretic Assembly of Carbon Nanotubes." Advanced Materials Research 750-752 (August 2013): 328–31. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.328.
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Dielectrophoresis (DEP) has been verified to be an efficient means of assembling carbon nanotubes (CNTs) for various applications. This paper simulates the electric field distribution of the quadruple electrode structure when the external AC voltage is applied between a pair of opposite electrodes. There exist induced electric potentials between high voltage electrodes and floating electrodes and thus floating electrodes seriously change the field distribution. For a pair of wide parallel electrodes, the deposition of one CNT bridging the electrode pair will greatly alter the local electric field and repel the further deposition of CNTs in the vicinity. The screening distance is relevant with the width of the electrode gap, which provides a way to estimate the density of assembled CNTs between the electrode pair.
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Wójcik, Szymon, and Małgorzata Jakubowska. "Optimization of anethole determination using differential pulse voltammetry on glassy carbon electrode, boron doped diamond electrode and carbon paste electrode." Science, Technology and Innovation 3, no. 2 (December 27, 2018): 21–26. http://dx.doi.org/10.5604/01.3001.0012.8152.
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Voltammetry is the general term for all techniques in which the current is measured as a function of electrode potential. The voltammetric techniques can be applied for the quantitative analysis of inorganic and organic species and are best suited for substances which can be either oxidized or reduced on electrodes. These techniques are characterized by high sensitivity which results in the possibility of performing determinations at a low concentration level. In voltammetry, many different types of working electrodes are applied. One of the important groups are solid electrodes, among which carbon electrodes play an important role. They represent a good alternative to mercury electrodes, however, surface preparation before the usage is required. In this work anethole determination will be presented using three types of carbon electrodes: glassy carbon electrode, boron doped diamond electrode and carbon paste electrode. Optimization process will be also described.
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Cong, Ruye, Hyun-Ho Park, Minsang Jo, Hochun Lee, and Chang-Seop Lee. "Synthesis and Electrochemical Performance of Electrostatic Self-Assembled Nano-Silicon@N-Doped Reduced Graphene Oxide/Carbon Nanofibers Composite as Anode Material for Lithium-Ion Batteries." Molecules 26, no. 16 (August 10, 2021): 4831. http://dx.doi.org/10.3390/molecules26164831.
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Silicon-carbon nanocomposite materials are widely adopted in the anode of lithium-ion batteries (LIB). However, the lithium ion (Li+) transportation is hampered due to the significant accumulation of silicon nanoparticles (Si) and the change in their volume, which leads to decreased battery performance. In an attempt to optimize the electrode structure, we report on a self-assembly synthesis of silicon nanoparticles@nitrogen-doped reduced graphene oxide/carbon nanofiber (Si@N-doped rGO/CNF) composites as potential high-performance anodes for LIB through electrostatic attraction. A large number of vacancies or defects on the graphite plane are generated by N atoms, thus providing transmission channels for Li+ and improving the conductivity of the electrode. CNF can maintain the stability of the electrode structure and prevent Si from falling off the electrode. The three-dimensional composite structure of Si, N-doped rGO, and CNF can effectively buffer the volume changes of Si, form a stable solid electrolyte interface (SEI), and shorten the transmission distance of Li+ and the electrons, while also providing high conductivity and mechanical stability to the electrode. The Si@N-doped rGO/CNF electrode outperforms the Si@N-doped rGO and Si/rGO/CNF electrodes in cycle performance and rate capability, with a reversible specific capacity reaching 1276.8 mAh/g after 100 cycles and a Coulomb efficiency of 99%.
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Xu, Qiang, Yiyi She, and Li Li. "Model-based analysis of geometrical effects in microfluidic fuel cell with flow-through porous electrodes." International Journal of Modern Physics B 34, no. 01n03 (November 11, 2019): 2040022. http://dx.doi.org/10.1142/s0217979220400226.
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Porous electrodes in microfluidic fuel cell (MFC) operate with nonuniform reaction rate. It is intriguing to improve the utilization degree of the porous electrodes. In this work, a three-dimensional computational model is developed for MFC with flow-through porous electrodes. Characteristics of the reaction rate distributions under different electrode geometries are examined. The results show that reaction rate varies noticeably along the electrode width direction, but minimally along the electrode length direction. High reaction rate region locates in the vicinity of the interface between the porous electrode and the middle channel. A relatively high aspect ratio, defined as the ratio of the electrode length to width, is beneficial to improve the utilization degree of the porous electrodes. Yet, concentration losses increase due to the decreased fluid velocity. Considering the cell performance, optimal electrode aspect ratios are derived for the anode and cathode, respectively.
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Ding, Xue-Feng, Yan Gao, Hui Zhang, Yuan Zhang, Shao-Xia Wang, Yong-Qi Zhao, Yi-Zheng Wang, and Ming Fan. "A novel low-cost electrode for recording the local field potential of freely moving rat’s brain." Translational Neuroscience 11, no. 1 (June 5, 2020): 96–104. http://dx.doi.org/10.1515/tnsci-2020-0104.
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AbstractLocal field potentials (LFPs) are involved in almost all cognitive activities of animals. Several kinds of recording electrodes are used for recording LFPs in freely moving animals, including commercial and homemade electrodes. However, commercial recording electrodes are expensive, and their relatively fixed size often causes a steric hindrance effect, especially when combining deep brain stimulation (DBS) with LFP recording, which may not always satisfy the aim of researchers. Currently, an increasing number of researchers are designing their own recording electrodes to lower research costs. Nevertheless, there is no simple universal method to produce low-cost recording electrodes with a specific size according to the target brain area. Thus, we developed a simple method for quickly producing low-cost multiple-channel recording electrodes. To inspect the effectiveness of our self-designed electrode, LFPs were recorded in a Parkinson’s disease (PD) rat model, and an electrical stimulation electrode was implanted into the subthalamic nucleus to verify the space-saving ability of the self-designed recording electrode. The results showed that <30 min was needed to prepare an electrode and that the electrode materials cost <5 dollars. Further investigations showed that our electrode successfully recorded the beta oscillations (12–40 Hz) in the PD rat model. Thus, this method will greatly reduce the cost of recording electrodes and save time for researchers. Additionally, the small size of the electrode will further facilitate DBS research.
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LaViolette, Peter S., Scott D. Rand, Manoj Raghavan, Benjamin M. Ellingson, Kathleen M. Schmainda, and Wade Mueller. "Three-Dimensional Visualization of Subdural Electrodes for Presurgical Planning." Operative Neurosurgery 68, suppl_1 (March 1, 2011): ons152—ons161. http://dx.doi.org/10.1227/neu.0b013e31820783ba.
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Abstract BACKGROUND: Accurate localization and visualization of subdural electrodes implanted for intracranial electroencephalography in cases of medically refractory epilepsy remains a challenging clinical problem. OBJECTIVE: We introduce a technique for creating accurate 3-dimensional (3D) brain models with electrode overlays, ideal for resective surgical planning. METHODS: Our procedure uses postimplantation magnetic resonance imaging (MRI) and computed tomographic (CT) imaging to create 3D models of compression-affected brain combined with intensity-thresholded CT-derived electrode models using freely available software. Footprints, or “shadows,” beneath electrodes are also described for better visualization of sulcus-straddling electrodes. Electrode models were compared with intraoperative photography for validation. RESULTS: Realistic representations of intracranial electrode positions on patient-specific postimplantation MRI brain renderings were reliably created and proved accurate when compared with photographs. Electrodes placed interhemispherically were also visible with our rendering technique. Electrode shadows were useful in locating electrodes that straddle sulci. CONCLUSION: We present an accurate method for visualizing subdural electrodes on brain compression effected 3D models that serves as an ideal platform for surgical planning.
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Rücker, Carsten, and Thomas Günther. "The simulation of finite ERT electrodes using the complete electrode model." GEOPHYSICS 76, no. 4 (July 2011): F227—F238. http://dx.doi.org/10.1190/1.3581356.
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Direct-current resistivity surveys usually are performed using steel rods of finite extent and grounding resistance. However, in modeling, electrodes are commonly treated as ideal point sources. We present an approach for numerical computation applying the complete electrode model (CEM), which is known from medical imaging. The electrode surface was discretized, and the partial-differential equations were extended by additional relations incorporating a contact impedance and a condition for the current flow through the electrode surface. We verified the modeling of the electrical potential using an analytical solution for a perfectly coupled half-ellipsoid current source. To quantify the influence of a finite electrode, we computed the electrode effect as the ratio between CEM and point-source solution and investigated its dependence on geometry and contact impedance. Surface measurements using rods of typical spatial extent showed electrode effects on the order of the measuring accuracy for an electrode length/spacing ratio lower than 0.2. However, the effects are more significant for closed geometries such as experimental tanks. A comparison with a point approximation for finite electrodes using point-source locations along the electrode axis showed the best agreement, with points at about 60% of the electrode extension. The contact impedance played a minor role for four-point measurements, contributing only a few percent to the electrode effect. In addition to penetrating electrodes, we investigated surface electrodes with galvanic or capacitive coupling, showing electrode effects on the same order as for penetrating electrodes. An inhomogeneous resistivity distribution clearly increased the size of the effects. We also investigate the use of CEM to simulate current injected through steel-cased boreholes. Finally, we applied the approach with buried ring electrodes to calculate effects caused mainly by geometric disturbances from the borehole.
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McGehee, Michael D. "Nanostructured Organic–Inorganic Hybrid Solar Cells." MRS Bulletin 34, no. 2 (February 2009): 95–100. http://dx.doi.org/10.1557/mrs2009.27.
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AbstractWhen light is absorbed in organic semiconductors, bound electron–hole pairs known as excitons are generated. The electrons and holes separate from each other at an interface between two semiconductors by electron transfer. It is advantageous to form well-ordered nanostructures so that all of the excitons can reach the interface between the two semiconductors and all of the charge carriers have a pathway to the appropriate electrode. This article discusses charge and exciton transport in organic semiconductors, as well as the opportunities for making highly efficient solar cells and for using carbon nanotubes to replace metal oxide electrodes.
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Wu, Jia Jia, Yi Wang, and Dun Zhang. "Reduced Graphene Sheets as Catalysts for Oxygen Reduction Reaction in Alkaline Media." Advanced Materials Research 197-198 (February 2011): 667–71. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.667.
Full textAbstract:
Reduced graphene sheets (RGSs) were prepared via hydrazine reduction of exfoliated graphite oxide and their morphology was characterized by atomic force microscopy. The electrocatalytic reduction of oxygen (O2) with RGSs was studied by cyclic and rotating risk electrode voltammetry using RGSs-modified glassy carbon electrodes in alkaline media. The results show that this modification with RGSs makes the peak potential shift in the positive direction and increases the peak current. The kinetics study shows that the numbers of electrons transferred for the oxygen reduction reaction are ca. 3 at potentials of the first reduction wave, indicating the peroxide produced can transfer into OH–.