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Journal articles on the topic 'Conjugated Polymer; Nanocomposites; Photo Catalysts'
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Kakarla, Raghava Reddy, Benaka Prasad S.B., Mo Jeong Han, and V. Raghu Anjanapura. "PHOTOCATALYTIC ACTIVITY OF TITANIUM DIOXIDECONJUGATED POLYMER COMPOSITE NANOPARTICLES SYNTHESIZED BY CHEMICAL OXIDATIVE POLYMERIZATION." INTERNATIONAL JOURNAL OF RESEARCH- GRANTHAALAYAH 5, no. 4 RAST (2017): 1–6. https://doi.org/10.5281/zenodo.803410.
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An organo-inorganic photocatalytic nanocomposite material based on conjugated polymer, polyaniline (PANI) with TiO2 nanoparticles has been synthesized by performing in situ chemical oxidative polymerization of aniline with ammoniumpersulfate (APS) oxidant in the presence of TiO2 nanoparticles. Morphological and structural properties of TiO2-PANI nanocomposites were analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), respectively. FT-IR spectra show that the nanocomposites are almost identical to the structure of PANI alone. The photocatalytic activities of the nanocomposites were evaluated by photocatalytic degradation of Rhodamine B (RhB) under UV-light. The composites exhibited higher photocatalytic activity for the degradation of RhB than unmodified TiO2 nanoparticles, which is due to sensitizing effect of PANI.
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Das, Suma, and Avijit Chowdhury. "Recent advancements of g-C3N4-based magnetic photocatalysts towards the degradation of organic pollutants: a review." Nanotechnology 33, no. 7 (2021): 072004. http://dx.doi.org/10.1088/1361-6528/ac3614.
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Abstract Heterogeneous photocatalysis premised on advanced oxidation processes has witnessed a broad application perspective, including water purification and environmental remediation. In particular, the graphitic carbon nitride (g-C3N4), an earth-abundant metal-free conjugated polymer, has acquired extensive application scope and interdisciplinary consideration owing to its outstanding structural and physicochemical properties. However, several issues such as the high recombination rate of the photo-generated electron–hole pairs, smaller specific surface area, and lower electrical conductivity curtail the catalytic efficacy of bulk g-C3N4. Another challenging task is separating the catalyst from the reaction medium, limiting their reusability and practical applications. Therefore, several methodologies are adopted strategically to tackle these issues. Attention is being paid, especially to the magnetic nanocomposites (NCs) based catalysts to enhance efficiency and proficient reusability property. This review summarizes the latest progress related to the design and development of magnetic g-C3N4-based NCs and their utilization in photocatalytic systems. The usefulness of the semiconductor heterojunctions on the catalytic activity, working mechanism, and degradation of pollutants are discussed in detail. The major challenges and prospects of using magnetic g-C3N4-based NCs for photocatalytic applications are highlighted in this report.
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Aharon, Eyal, Michael Kalina, and Gitti L. Frey. "Inhibition of Energy Transfer between Conjugated Polymer Chains in Host/Guest Nanocomposites Generates White Photo- and Electroluminescence." Journal of the American Chemical Society 128, no. 50 (2006): 15968–69. http://dx.doi.org/10.1021/ja066290m.
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Ma, Xingfa, Caiwei Li, Xintao Zhang, Mingjun Gao, and Guang Li. "Broadband Spectrum Light-Driven PANI/Au/Beta-Cyclodextrin Nanocomposite and Its Light-Triggered Interfacial Carrier Transfer." Coatings 12, no. 10 (2022): 1401. http://dx.doi.org/10.3390/coatings12101401.
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Polyaniline/Au nanocomposites were synthesized by a novel method. Aniline monomers were loaded in the hydrophobic cavities of beta-cyclodextrin, and a polymerization reaction occurred at the interface of the beta-cyclodextrin cavities and the liquid phase of chloroauric acid. UV-vis absorbance indicated that the nanocomposite covered the range of visible light and NIR (near infrared). The photo-excitation experiment was carried out with typical wavelengths in the visible light (405 nm, 532 nm, and 650 nm) and NIR (780 nm, 808 nm, 980 nm, and 1064 nm) regions (10–200 mW) based on Au inter-digital electrodes on flexible polymer substrates casting a thick film. The nanocomposites exhibited photo-current switching behavior in visible light and NIR. The ratio of on/off was enormously dependent on the power and wavelength of incident light. The robust interface coupling between Au and PANi of the nanocomposite promoted the separation and transfer of electron/hole. The mechanism of carrier generation, separation, and transfer at interfaces of Au/conjugated polymer/non-conjugated small organic molecules by light inducement was discussed at the electron level. The results illustrate that the nanocomposites quickly produced free electrons and holes by low-power incident light, could prevent the recombination of electron/hole pairs to a certain extent, and could overcome the interface barriers between metal, conjugated polymer, and small organic molecules for transfer. This provides a simple and practical approach for developing multi-functional nanocomposites that have the potential act as intelligent nano-carriers, photo-current switches, NIR detectors, and for information storage.
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Taik Lim, Yong, Tae-Woo Lee, Ho-Chul Lee, and O. Ok Park. "Enhanced photo-stability of conjugated polymer nanocomposites doped with functionalized nanoparticles." Optical Materials 21, no. 1-3 (2003): 585–89. http://dx.doi.org/10.1016/s0925-3467(02)00205-7.
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Fortin, Patrick, Subash Rajasekar, Pankaj Chowdhury, and Steven Holdcroft. "Hydrogen evolution at conjugated polymer nanoparticle electrodes." Canadian Journal of Chemistry 96, no. 2 (2018): 148–57. http://dx.doi.org/10.1139/cjc-2017-0329.
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Organic polymer nanoparticles have been gaining attention in photovoltaics as a means to control the morphology of polymer composite films for the purpose of studying bulk heterojunction, photoactive layers. This work investigates the preparation of nanostructured organic thin films from P3HT:PC61BM nanoparticles and their characterization as photoelectrodes for the photoelectrochemical reduction of hydrogen in acidic solutions. The morphology and optoelectronic properties of the nanostructured photocathodes are compared with conventional, solution-cast thin films of P3HT:PC61BM. The nanostructured photoelectrodes provide increased surface area compared with solution-cast films through control of the nanoscale morphology within each nanoparticle, leading to enhanced P3HT:PC61BM phase segregation. The photo-assisted deposition of platinum nanoparticles as hydrogen evolution reaction (HER) catalysts onto the nanostructured P3HT:PC61BM photocathodes facilitates the photoreduction of protons to H2.
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Ma, Xingfa, Caiwei Li, Mingjun Gao, Xintao Zhang, You Wang, and Guang Li. "Interface Optimization of Metal Quantum Dots/Polymer Nanocomposites and their Properties: Studies of Multi-Functional Organic/Inorganic Hybrid." Materials 16, no. 1 (2022): 150. http://dx.doi.org/10.3390/ma16010150.
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Nanomaterials filled polymers system is a simple method to produce organic/inorganic hybrid with synergistic or complementary effects. The properties of nanocomposites strongly depend on the dispersion effects of nanomaterials in the polymer and their interfaces. The optimized interface of nanocomposites would decrease the barrier height between filler and polymer for charge transfer. To avoid aggregation of metal nanoparticles and improve interfacial charge transfer, Pt nanodots filled in the non-conjugated polymer was synthesized with an in situ method. The results exhibited that the absorbance of nanocomposite covered from the visible light region to NIR (near infrared). The photo-current responses to typical visible light and 808 nm NIR were studied based on Au gap electrodes on a flexible substrate. The results showed that the size of Pt nanoparticles was about 1–2 nm and had uniformly dispersed in the polymer matrix. The resulting nanocomposite exhibited photo-current switching behavior to weak visible light and NIR. Simultaneously, the nanocomposite also showed electrical switching responses to strain applied to a certain extent. Well-dispersion of Pt nanodots in the polymer is attributable to the in situ synthesis of metal nanodots, and photo-current switching behavior is due to interface optimization to decrease barrier height between metal filler and polymer. It provided a simple way to obtain organic/inorganic hybrid with external stimuli responses and multi-functionalities.
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Fortin, Patrick, and Steven Holdcroft. "Hydrogen Evolution at Conjugated Polymer Nanoparticle Electrodes." ECS Meeting Abstracts MA2018-01, no. 31 (2018): 1909. http://dx.doi.org/10.1149/ma2018-01/31/1909.
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Currently, there is a global effort being made to reduce greenhouse gas emissions through the implementation of renewable energies. An attractive alternative to fossil fuels is hydrogen, as it can be stored, transported and used as on demand as a liquid fuel while producing only water vapor as a by-product. The production of hydrogen can be attained through the photoelectrochemical splitting of water into hydrogen and oxygen, representing a sustainable, carbon neutral method of hydrogen generation. Our research focuses on the use of conjugated polymers, namely poly(3-hexylthiophene) (P3HT), as photocathode materials to convert solar energy into hydrogen. Using phenyl-C61-butryic acid methyl ester (PCBM) as an electron acceptor to effectively separate the photogenerated electron-hole pair within the semiconducting polymer, we can take advantage of these separated charges to perform electrochemical reactions at the polymer/electrolyte interface. This work investigates the preparation of nanostructured organic thin films from P3HT:PCBM nanoparticles and their characterization as photoelectrodes for photoelectrochemical hydrogen evolution. The morphology and optoelectronic properties of the nanostructured photocathodes are compared with conventional, solution-cast thin films of P3HT:PCBM. The nanostructured photoelectrodes provide increased surface area compared with solution-cast films, as well as greater control of the nanoscale morphology within each nanoparticle, leading to enhanced P3HT:PCBM phase segregation. The photo-assisted deposition of platinum nanoparticles as hydrogen evolution reaction (HER) catalysts onto the nanostructured P3HT:PCBM photocathodes facilitates the photoreduction of protons to H2.
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Li, Caifang, Xianliang Wu, Junyue Shan, Jing Liu, and Xianfei Huang. "Preparation, Characterization of Graphitic Carbon Nitride Photo-Catalytic Nanocomposites and Their Application in Wastewater Remediation: A Review." Crystals 11, no. 7 (2021): 723. http://dx.doi.org/10.3390/cryst11070723.
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Energy crisis and environmental pollution are the major problems of human survival and development. Photocatalytic technology can effectively use solar energy and is prospective to solve the above-mentioned problems. Carbon nitride is a two-dimensional polymer material with a graphite-like structure. It has good physical and chemical stabilities, unique chemical and electronic energy band structures, and is widely used in the field of photocatalysis. Graphitic carbon nitride has a conjugated large π bond structure, which is easier to be modified with other compounds. thereby the surface area and visible light absorption range of carbon nitride-based photocatalytic composites can be insignificantly increased, and interface electron transmission and corresponding photogenerated carriers separation of streams are simultaneously promoted. Therefore, the present study systematically introduced the basic catalytic principles, preparation and modification methods, characterization and calculation simulation of carbon nitride-based photocatalytic composite materials, and their application in wastewater treatment. We also summarized their application in wastewater treatment with the aid of artificial intelligence tools. This review summarized the frontier technology and future development prospects of graphite phase carbon nitride photocatalytic composites, which provide a theoretical reference for wastewater purification.
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Zhang, Linzhu, Lu Chen, Yuzhou Xia, et al. "Modification of Polymeric Carbon Nitride with Au–CeO2 Hybrids to Improve Photocatalytic Activity for Hydrogen Evolution." Molecules 27, no. 21 (2022): 7489. http://dx.doi.org/10.3390/molecules27217489.
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The construction of a multi-component heterostructure for promoting the exciton splitting and charge separation of conjugated polymer semiconductors has attracted increasing attention in view of improving their photocatalytic activity. Here, we integrated Au nanoparticles (NPs) decorated CeO2 (Au–CeO2) with polymeric carbon nitride (PCN) via a modified thermal polymerization method. The combination of the interfacial interaction between PCN and CeO2 via N-O or C-O bonds, with the interior electronic transmission channel built by the decoration of Au NPs at the interface between CeO2 and PCN, endows CeAu–CN with excellent efficiency in the transfer and separation of photo-induced carriers, leading to the enhancement of photochemical activity. The amount-optimized CeAu–CN nanocomposites are capable of producing ca. 80 μmol· H2 per hour under visible light irradiation, which is higher than that of pristine CN, Ce–CN and physical mixed CeAu and PCN systems. In addition, the photocatalytic activity of CeAu–CN remains unchanged for four runs in 4 h. The present work not only provides a sample and feasible strategy to synthesize highly efficient organic polymer composites containing metal-assisted heterojunction photocatalysts, but also opens up a new avenue for the rational design and synthesis of potentially efficient PCN-based materials for efficient hydrogen evolution.
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Riberi, Kevin, Silvestre Bongiovanni Abel, María V. Martinez, et al. "Smart Thermomechanochemical Composite Materials Driven by Different Forms of Electromagnetic Radiation." Journal of Composites Science 4, no. 1 (2020): 3. http://dx.doi.org/10.3390/jcs4010003.
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Photo-thermo-mechanochemical (P-T-MCh) nanocomposites provide a mechanical and/or chemical output (MCh) in response to a photonic (P) input, with the thermal (T) flux being the coupling factor. The nanocomposite combines a photon absorbing nanomaterial with a thermosensitive hydrogel matrix. Conjugated (absorbing in the near infrared (NIR, 750–850 nm) wavelength range) polymer (polyaniline, PANI) nanostructures are dispersed in cross-linked thermosensitive (poly(N-isopropylacrylamide), PNIPAM) hydrogel matrices, giving the nanocomposite P-T-MCh properties. Since PANI is a conductive polymer, electromagnetic radiation (ER) such as radiofrequency (30 kHz) and microwaves (2.4 GHz) could also be used as an input. The alternating electromagnetic field creates eddy currents in the PANI, which produces heat through the Joule effect. A new kind of “product” nanocomposite is then produced, where ER drives the mechanochemical properties of the material through thermal coupling (electromagnetic radiation thermomechanochemical, ER-T-MCh). Both optical absorption and conductivity of PANI depend on its oxidation and protonation state. Therefore, the ER-T-MCh materials are able to react to the surroundings properties (pH, redox potential) becoming a smart (electromagnetic radiation thermomechanochemical) (sER-T-MCh) material. The volume changes of the sER-T-MCh materials are reversible since the size and shape is recovered by cooling. No noticeable damage was observed after several cycles. The mechanical properties of the composite materials can be set by changing the hydrogel matrix. Four methods of material fabrication are described.
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Allen, Norman S. "Book Review: Light Harvesting NanoMaterials, Bentham e-Books, ISBN: 978-1-60805-959-1; e-ISBN: 978-1-60805-958-4." Open Materials Science Journal 9, no. 1 (2015): 49. http://dx.doi.org/10.2174/1874088x01509010049.
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Light Harvesting NanoMaterials, Bentham e-Books, ISBN: 978-1-60805-959-1;e- ISBN: 978-1-60805-958-4 Edited by Surya Prakash Singh The harvesting, capture and efficient conversion of solar light energy into electrical and heat energy through chemical and structural materials is now a rapid and exciting field of significant advancement and investigation in the scientific world. Many of these novel and often complex materials can attain important developments for many industrial outlets in energy transformation from solar power. This book targets a number of key newly developed nano-materials and consists in total of five chapters each one compiled by authors who are experts in that particular field and is edited by Surya Prakash Singh. The book consists of a number of important topics many developmental in the fields of organic/polymeric nano-materials which brings the reader up-to-date on many important features. The first chapter covers recent investigations covering the inter-locking and embedding of inorganic transistion metal compound based nano-particles onto solar panel surfaces as anti-reflective coatings in order to enhance light absorption characteristics for effective energy conversion. Silicon, titanium and silver compounds in various nano-formats are highlighted. Here the properties of the particles in harvesting light energy as a support and their photochemistry provides many important answers to questions in relation to the efficiencies of energy harnessing. The efficiencies of these processes is examined practically and theoretically in some depth with many very well illustrated devices. Silver nano-particles were particularly valuable and effective in this regard for enhancing solar energy absorption. Nano-crystalline titanium dioxide is a widely investigated material for solar energy harnessing but its inefficiency in absorption like many materials is a major deficiency. In chapter two, the use of doped titanias utilising tetrapyrolic sensitisers and various metal complexes for overcoming this problem is reviewed. Here, the deficiencies of usual ruthenium complexes is superseded via more effective porphyrins, phthalocyanines and corroles and with enhanced coupling i.e. via zinc significant energy conversions may be achieved. The next chapter explores the behavior and properties of polymeric materials as matrices for nano-composites where again energy efficiency conversion is crucial in determining the role of the light induced physic-chemicalprocesses. In this case the design of polymer based nanocomposites is widely assessed and is proving to be one of the most interesting and upcoming fields in solar energy harnessing. Of course, one major setback in this area with organo-materials is durability. In chapter four, one rather interesting area of growing interest in utilising solar energy is that dealing with gold and titania nanoparticles called “plasmonic photocatalysts”. This important field has direct relevance to photo-induced electrical and semiconductor processes aswell as significance in the manufacture of photoelectrochemical catalysts due to their broad visible absorption characteristics and hence high efficiency. In this context, the formulation and properties of the various catalysts can result in the production of novel highly active material complexes with high efficacy for oxidation of organic compounds. In the last chapter C60-based solar cells with copper oxides, CuInS2, phthalocyanines, diamond, porphyrin and exciton-diffusion blocking layers have been fabricated and characterized for use in energy efficient solar cell construction. High efficiencies are observed in all these devices when utilized with C60. To summarize, this important edited text provides the reader with a highly useful and valuable source of scientific information which focuses on many important aspects of development in light energy harvesting processes in both fields of photochemistry and photophysics thus providing many valuable ways forward for further scientific development for the future in solar energy conversion and photocatalysis. It makes interesting reading coupled with many new ideas and is very well illustrated and certainly provides a valuable reference source for chemists, physicists, biologists and engineers working in the field in both academia, government and industry, alike.
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Chen, Guanying, Xiaoyu Guo, Bo Hu, and Lin Lei. "Heterogeneous Catalysts Catalyzed Photo‐Atom Transfer Radical Polymerization (Photo‐ATRP)." Macromolecular Chemistry and Physics, September 28, 2024. http://dx.doi.org/10.1002/macp.202400249.
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AbstractPhoto‐ATRP technique has garnered significant attention due to its multitude of advantages, including its ability to be conducted under mild reaction conditions, user‐friendly nature, and exceptional efficiency in polymerization. The heterogeneous photocatalysts not only exhibit exceptional quantum efficiency, but also possess a versatile bandgap that can be finely adjusted to accommodate a wide range of absorption wavelengths within the visible light spectrum, thereby emphasizing their potential for efficient recovery and reuse. The utilization of a variety of heterogeneous photocatalysts in photo‐ATRP presents notable benefits for numerous applications, such as the lack of any remaining substances, simplicity in usage, and potential for reuse. This review focuses on recent progress in photo‐ATRP utilizing a wide variety of heterogeneous photocatalysts, encompassing metal semiconductor nanoparticles, quantum dot, upconversion nanoparticles, metal–organic frameworks, covalent–organic frameworks, conjugated microporous polymers, hypercrosslinked polymer, and carbon‐based materials.
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"TiO2 Supported in Polymethyl methacrylate (PMMA) Properties, Preparation, and Photocatalytic Activity for the Degradation of Synthetic Dyes." Letters in Applied NanoBioScience 13, no. 1 (2024): 13. https://doi.org/10.33263/lianbs131.013.
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The immobilization of titanium dioxide (TiO2), a prominent photo-catalyst, on various substrates has received a lot of interest over the last two decades since it avoids the need for costly post-treatment separation methods. Among the many substrates tested for supporting TiO2 photo-catalysts, polymer substrate appears to be the most promising due to multiple advantages such as its flexible nature, low cost, chemical resistance, mechanical stability, low density, high durability, and ease of availability. The proximity of photo-catalysis and the support system significantly increased the transfer step between adsorption and the total oxidative decolorization process. A comparison of photodecolorization with many synthetic dyes was made, and it was found that the structural and surface features of the photo-catalyst influenced the photocatalytic activities. This review focuses on TiO2-PMMA nanocomposites and thoroughly investigates the synthesis, photocatalytic activity, and reuse of TiO2/PMMA photo-catalysts. Finally, the future study scope and commercialization problems of PMMA-supported TiO2 photo-catalysts in visible and/or solar light have been highlighted.
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Bayarkhuu, Bolormaa, Hyekyung Cho, Gaeun Cho, et al. "Engineering Single‐Atom Catalysts on Conjugated Porphyrin Polymer Photocatalysts via E‐Waste for Sustainable Photocatalysis." Advanced Functional Materials, July 28, 2024. http://dx.doi.org/10.1002/adfm.202411661.
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AbstractThis study presents a surface engineering strategy utilizing electronic waste (e‐waste) to incorporate single‐atom catalysts on conjugated polymers. Employing a conjugated porphyrin polymeric photocatalyst, gold single‐atom‐site catalysts are successfully introduced using the acidic metal leachates from e‐waste, where metal speciation and composition are regulated during the metal loading processes. The resulting photocatalyst with gold single atoms demonstrates a remarkable hydrogen peroxide (H2O2) selectivity of up to 97.56%, yielding a pure H2O2 solution at 73.3 µm h−1 under white LED illumination. The produced H2O2 is activated to •OH radicals on the same polymer with mixed gold and iron atoms, enabling a photo‐Fenton reaction and the complete degradation of toxic microcystin‐LR within 10 min under visible light. This study highlights the universal applicability of the metal mining strategy in various photoreactions. It is believed that this discovery pioneers sustainable photocatalysis, allowing the tuning of reactivity and selectivity on photocatalytic surfaces using metal waste.
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Hu, Zhuang, Feng Gao, Haiyan Qin, et al. "Bright Nanocomposites based on Quantum Dot‐Initiated Photocatalysis." Angewandte Chemie, October 2024. http://dx.doi.org/10.1002/ange.202415645.
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Integrating quantum dots (QDs) into polymer matrix to form nanocomposites without compromising the QD photoluminescence (PL) is crucial to emerging QD light‐emitting and solar energy conversion fields. However, the most widely‐used bulk polymerization technique, where monomers serve as the QD solvent, usually leads to QD PL quenching caused by radical initiators. Here we demonstrate high‐brightness nanocomposites with near‐unity PL quantum yield (QY), through a novel QDs‐catalyzed (‐initiated) bulk polymerization without using any radical initiators. Different from previous reports where QDs were designed as photo‐sensitizers/catalysts (always with cocatalysts) and hence non‐emissive in catalytic conditions, our QDs combine high brightness with highly effective catalysis, a combination that was previously considered to be hardly possible. In our case, apart from emitting light (at a large probability), the photoexcited QDs act as ‘overall reaction’ catalysts by simultaneously employing photoexcited electrons and holes to produce active radicals without the need of any sacrificial agents. These active radicals, though with a small amount, are sufficient to initiate effective chain reaction‐dominated bulk polymerization, eliminating the requirement of extra radical initiators. This study provides new insights for understanding and development of QDs for energy applications.
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Hu, Zhuang, Feng Gao, Haiyan Qin, et al. "Bright Nanocomposites based on Quantum Dot‐Initiated Photocatalysis." Angewandte Chemie International Edition, October 2024. http://dx.doi.org/10.1002/anie.202415645.
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Integrating quantum dots (QDs) into polymer matrix to form nanocomposites without compromising the QD photoluminescence (PL) is crucial to emerging QD light‐emitting and solar energy conversion fields. However, the most widely‐used bulk polymerization technique, where monomers serve as the QD solvent, usually leads to QD PL quenching caused by radical initiators. Here we demonstrate high‐brightness nanocomposites with near‐unity PL quantum yield (QY), through a novel QDs‐catalyzed (‐initiated) bulk polymerization without using any radical initiators. Different from previous reports where QDs were designed as photo‐sensitizers/catalysts (always with cocatalysts) and hence non‐emissive in catalytic conditions, our QDs combine high brightness with highly effective catalysis, a combination that was previously considered to be hardly possible. In our case, apart from emitting light (at a large probability), the photoexcited QDs act as ‘overall reaction’ catalysts by simultaneously employing photoexcited electrons and holes to produce active radicals without the need of any sacrificial agents. These active radicals, though with a small amount, are sufficient to initiate effective chain reaction‐dominated bulk polymerization, eliminating the requirement of extra radical initiators. This study provides new insights for understanding and development of QDs for energy applications.
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Xiao, Yang, Zhinan Xia, Wanchao Hu, Bei Liu, and Changli Lü. "Phenanthroline Derived N‐Doped Carbon Dots as Robust Metal‐Free Photocatalysts for PET‐RAFT Polymerization and Polymerization‐Induced Self‐Assembly." Small, March 22, 2024. http://dx.doi.org/10.1002/smll.202309893.
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AbstractMetal‐free organic photocatalysts for photo‐mediated reversible deactivation radical polymerization (photo‐RDRP) are witnessed to make increasing advancement in the precise synthesis of polymers. However, challenges still exist in the development of high‐efficiency and environmentally sustainable carbon dots (CDs)‐based organocatalysts. Herein, N‐doped CDs derived from phenanthroline derivative (Aphen) are prepared as metal‐free photocatalysts for photoinduced electron transfer reversible addition‐fragmentation chain transfer (PET‐RAFT) polymerization. The introduction of phenanthroline structure enhances the excited state lifetime of CDs and expands the conjugated length of their internal structure to enable the light‐absorption to reach green light region, thereby enhancing photocatalytic activity. The as‐designed CDs exhibit unprecedented photocatalytic capacity in photopolymerization even in large‐volume reaction (100 mL) with high monomer conversion and narrow polymer dispersity (Mw/Mn < 1.20) under green light. The photocatalytic system is compatible with PET‐RAFT polymerization of numerous monomers and the production of high molecular weight polyacrylate (Mn >250 000) with exquisite spatiotemporal control. Above results confirm the potential of CDs as photocatalyst, which has not been achieved with other CDs catalysts used in photo‐RDRP. In addition, the construction of fluorescent polymer nanoparticles using CDs as both photocatalyst and phosphor through photoinitiated polymerization‐induced self‐assembly (Photo‐PISA) technology is successfully demonstrated for the first time.
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Zhong, Linfeng, Dongmei Han, and Dingshan Yu. "Research advances on conjugated microporous polymer-derived photocatalysts toward solar-to-hydrogen production." Energy Lab 2 (2024). https://doi.org/10.54227/elab.20240013.
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Photocatalytic hydrogen evolution (PHE) is a sustainable energy technology that directly produces green and renewable hydrogen fuel from water under the drive of solar energy, achieving the conversion from solar energy to hydrogen energy, while the critical mission toward highly efficient PHE is to develop efficient and durable semiconductor catalysts. In this context, the newly-emerged conjugated microporous polymers (CMPs) have been considered as prospective candidates for efficient PHE due to their low density, good light absorption, high surface area, permanent microporous, and wide availability of synthesis methods. In particular, their molecular customizability and modifiability enable the effective encoding of desirable light-harvesting moieties and photo-catalytically active units into the conjugated polymer backbone for high-performance PHE. Herein, this review provides a brief summary on the latest advancements based on CMP-derived photocatalysts for PHE. First, the synthesis methods, reaction routes, and photoactive units of CMP photocatalysts are elucidated. Subsequently, the feasible methods regarding how to improve the PHE performance of CMPs by expanding light absorption, improving the separation and transport of photogenerated carriers, and promoting surface reactions are put forward. Finally, potential challenges and future prospects for CMP-derived photocatalysts are also discussed.
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Tsai, Cheng‐Hang, Wei‐Cheng Chen, Yan‐Cheng Lin, et al. "Ultralow‐Energy‐Consumption Photosynaptic Transistor Utilizing Conjugated Polymers/Perovskite Quantum Dots Nanocomposites With Ligand Density Optimization." Small, August 12, 2024. http://dx.doi.org/10.1002/smll.202402567.
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AbstractThe photosynaptic transistor stands as a promising contender for overcoming the von Neumann bottleneck in the realm of photo‐communication. In this context, photonic synaptic transistors is developed through a straightforward solution process, employing an organic semiconducting polymer with pendant‐naphthalene‐containing side chains (PDPPNA) in combination with ligand‐density‐engineered CsPbBr3 perovskite quantum dots (PQDs). This fabrication approach allows the devices to emulate fundamental synaptic behaviors, encompassing excitatory postsynaptic current, paired‐pulse facilitation, the transition from short‐to‐long‐term memory, and the concept of “learning experience.” Notably, the phototransistor, incorporating the blend of the PDPPNA and CsPbBr3 PQDs washed with ethyl acetate, achieved an exceptional memory ratio of 104. Simultaneously, the same device exhibited an impressive paired‐pulse facilitation ratio of 223% at a moderate operating voltage of −4 V and an extraordinarily low energy consumption of 0.215 aJ at an ultralow operating voltage of −0.1 mV. Consequently, these low‐voltage synaptic devices, constructed with a pendant side‐chain engineering of organic semiconductors and a ligand density engineering of PQDs through a simple fabrication process, exhibit substantial potential for replicating the visual memory capabilities of the human brain.
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Tsai, Cheng‐Yu, Hsu‐Sheng Li, Kumasser Kusse Kuchayita, Hsin‐Chih Huang, Wei‐Nien Su, and Chih‐Chia Cheng. "Exfoliated 2D Nanosheet‐Based Conjugated Polymer Composites with P‐N Heterojunction Interfaces for Highly Efficient Electrocatalytic Hydrogen Evolution." Advanced Science, July 31, 2024. http://dx.doi.org/10.1002/advs.202407061.
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AbstractThey have achieved a significant breakthrough in the preparation and development of two‐dimensional nanocomposites with P‐N heterojunction interfaces as efficient cathode catalysts for electrochemical hydrogen evolution reaction (HER) and iodide oxidation reaction (IOR). P‐type acid‐doped polyaniline (PANI) and N‐type exfoliated molybdenum disulfide (MoS2) nanosheets can form structurally stable composites due to formation of P‐N heterojunction structures at their interfaces. These P‐N heterojunctions facilitate charge transfer from PANI to MoS2 structures and thus significantly enhance the catalytic efficiency of MoS2 in the HER and IOR. Herein, by combining efficient sodium‐functionalized chitosan‐assisted MoS2 exfoliation, electropolymerization of PANI on nickel foam (NF) substrate, and electrochemical activation, controllable and scalable Na‐Chitosan/MoS2/PANI/NF electrodes are successfully constructed as non‐noble metal‐based electrochemical catalysts. Compared to a commercial platinum/carbon (Pt/C) catalyst, the Na‐Chitosan/MoS2/PANI/NF electrode exhibits significantly lower resistance and overpotential, a similar Tafel slope, and excellent catalytic stability at high current densities, demonstrating excellent catalytic performance in the HER under acidic conditions. More importantly, results obtained from proton exchange membrane fuel cell devices confirm the Na‐Chitosan/MoS2/PANI/NF electrode exhibits a low turn‐on voltage, high current density, and stable operation at 2 V. Thus, this system holds potential as a replacement for Pt/C with feasibility for applications in energy‐related fields.
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Li, Yaqi, Sijie Wan, Weichen Liang, et al. "D–A Conjugated Polymer/CdS S‐Scheme Heterojunction with Enhanced Interfacial Charge Transfer for Efficient Photocatalytic Hydrogen Generation." Small, March 5, 2024. http://dx.doi.org/10.1002/smll.202312104.
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AbstractOwing to the improved charge separation and maximized redox capability of the system, Step‐scheme (S‐scheme) heterojunctions have garnered significant research attention for efficient photocatalysis of H2 evolution. In this work, an innovative linear donor–acceptor (D–A) conjugated polymer fluorene‐alt‐(benzo‐thiophene‐dione) (PFBTD) is coupled with the CdS nanosheets, forming the organic–inorganic S‐scheme heterojunction. The CdS/PFBTD (CP) composite exhibits an impressed hydrogen production rate of 7.62 mmol g−1 h−1 without any co‐catalysts, which is ≈14 times higher than pristine CdS. It is revealed that the outstanding photocatalytic performance is attributed to the formation of rapid electron transfer channels through the interfacial Cd─O bonding as evidenced by the density functional theory (DFT) calculations and in situ X‐ray photoelectron spectroscopy (XPS) analysis. The charge transfer mechanism involved in S‐scheme heterojunctions is further investigated through the photo‐irradiated Kelvin probe force microscopy (KPFM) analysis. This work provides a new point of view on the mechanism of interfacial charge transfer and points out the direction of designing superior organic–inorganic S‐scheme heterojunction photocatalysts.
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Vensaus, Priscila, Rolando M. Caraballo, Emiliano Tritto, et al. "Electroactive Prussian Blue Analogues/TiO2 Nanocomposites Obtained through SILAR Assembly in Mesoporous Nanoarchitectures." European Journal of Inorganic Chemistry, November 15, 2023. http://dx.doi.org/10.1002/ejic.202300576.
Full textAbstract:
The preparation of nanomaterials for energy applications such as intercalation batteries and materials that can act as substrates for water oxidation is a subject of major interest nowadays. In this work, we report the deposition of Prussian blue (PB) and its cobalt analogue (CoPBA) on mesoporous titania thin films (MTTF) using the successive ionic layer adsorption reaction (SILAR) technique under soft conditions. A bifunctional ligand, 1,10‐phenanthroline‐5,6‐dione (pd), was used to functionalize the titania surface and promote the growth of PB and CoPBA. The resulting PB@MTTF and CoPBA@MTTF nanocomposites were characterized using several techniques and it was determined that PB and CoPBA grow in a controlled and sequential manner, maintaining the mesoporous architecture. Both PB@MTTF and CoPBA@MTTF demonstrated very good electroactive properties, while CoPBA@MTTF exhibited water oxidation capabilities. The flexibility of this PBA@MTTF platform allows the incorporation of any labile transition metal ion or fragment into the structure of the coordination polymer embedded into a mesoporous matrix, opening the door for (photo)electrochemical devices and catalysts.