Academic literature on the topic 'Graphitic carbon nitride (g-C3N4)'
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Journal articles on the topic "Graphitic carbon nitride (g-C3N4)"
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Idris, Azeez O., Ekemena O. Oseghe, Titus A. M. Msagati, Alex T. Kuvarega, Usisipho Feleni, and Bhekie Mamba. "Graphitic Carbon Nitride: A Highly Electroactive Nanomaterial for Environmental and Clinical Sensing." Sensors 20, no. 20 (October 10, 2020): 5743. http://dx.doi.org/10.3390/s20205743.
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Graphitic carbon nitride (g-C3N4) is a two-dimensional conjugated polymer that has attracted the interest of researchers and industrial communities owing to its outstanding analytical merits such as low-cost synthesis, high stability, unique electronic properties, catalytic ability, high quantum yield, nontoxicity, metal-free, low bandgap energy, and electron-rich properties. Notably, graphitic carbon nitride (g-C3N4) is the most stable allotrope of carbon nitrides. It has been explored in various analytical fields due to its excellent biocompatibility properties, including ease of surface functionalization and hydrogen-bonding. Graphitic carbon nitride (g-C3N4) acts as a nanomediator and serves as an immobilization layer to detect various biomolecules. Numerous reports have been presented in the literature on applying graphitic carbon nitride (g-C3N4) for the construction of electrochemical sensors and biosensors. Different electrochemical techniques such as cyclic voltammetry, electrochemiluminescence, electrochemical impedance spectroscopy, square wave anodic stripping voltammetry, and amperometry techniques have been extensively used for the detection of biologic molecules and heavy metals, with high sensitivity and good selectivity. For this reason, the leading drive of this review is to stress the importance of employing graphitic carbon nitride (g-C3N4) for the fabrication of electrochemical sensors and biosensors.
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Baudys, Michal, Šárka Paušová, Petr Praus, Vlasta Brezová, Dana Dvoranová, Zuzana Barbieriková, and Josef Krýsa. "Graphitic Carbon Nitride for Photocatalytic Air Treatment." Materials 13, no. 13 (July 7, 2020): 3038. http://dx.doi.org/10.3390/ma13133038.
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Graphitic carbon nitride (g-C3N4) is a conjugated polymer, which recently drew a lot of attention as a metal-free and UV and visible light responsive photocatalyst in the field of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability and earth-abundant nature. In the present work, bulk g-C3N4 was synthesized by thermal decomposition of melamine. This material was further exfoliated by thermal treatment. S-doped samples were prepared from thiourea or further treatment of exfoliated g-C3N4 by mesylchloride. Synthesized materials were applied for photocatalytic removal of air pollutants (acetaldehyde and NOx) according to the ISO 22197 and ISO 22197-1 methodology. The efficiency of acetaldehyde removal under UV irradiation was negligible for all g-C3N4 samples. This can be explained by the fact that g-C3N4 under irradiation does not directly form hydroxyl radicals, which are the primary oxidation species in acetaldehyde oxidation. It was proved by electron paramagnetic resonance (EPR) spectroscopy that the dominant species formed on the irradiated surface of g-C3N4 was the superoxide radical. Its production was responsible for a very high NOx removal efficiency not only under UV irradiation (which was comparable with that of TiO2), but also under visible irradiation.
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Bai, Kaifei, Zhen Cui, Enling Li, Yingchun Ding, Jiangshan Zheng, Yanpeng Zheng, and Chang Liu. "Adsorption of alkali metals on graphitic carbon nitride: A first-principles study." Modern Physics Letters B 34, no. 32 (August 3, 2020): 2050361. http://dx.doi.org/10.1142/s0217984920503613.
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The electronic and optical properties of the adsorption of alkali metals (Li, Na, K, Rb, Cs) on graphitic carbon nitride (g-C3N[Formula: see text] were calculated and studied based on the first principles of density functional theory. The results investigate that alkali metals adsorbed g-C3N4 has metallic properties, while intrinsic g-C3N4 was semiconducting. Importantly, the charge density differential investigated the charge transfer discovered between the alkali metal and the g-C3N4 monolayer. Meanwhile, the charges (electrons) transfer from the alkali metals to the g-C3N4 system leading to the increase of most carriers in the g-C3N4 system, reducing the resistance of sensors, which is conducive to sensor detection applications. The work function of g-C3N4 decreased from 4.82 eV to 4.09 eV. Especially, the work function of Cs-adsorbed g-C3N4 is the lowest at 4.09 eV, and the reduction rate is 15.15 %, indicating it easier to emit electrons from an external electric field. Moreover, the absorption spectrum of the alkali metal adsorbed on g-C3N4 in the visible light range shows absorption peaks at 380 nm, 412 nm, 420 nm and 476 nm, which cover the visible light area. Thus, the alkali metals adsorbed g-C3N4 system can be used for visible light catalytic. Adsorption of alkali metals can expand the application of g-C3N4 in optoelectronic devices.
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Tang, Rong, Renli Ding, and Xianchuan Xie. "Preparation of oxygen-doped graphitic carbon nitride and its visible-light photocatalytic performance on bisphenol A degradation." Water Science and Technology 78, no. 5 (August 20, 2018): 1023–33. http://dx.doi.org/10.2166/wst.2018.361.
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Abstract A novel metal-free oxygen-doped graphitic carbon nitride (O-g-C3N4) was synthesized by the pre-treatment of bulk graphitic carbon nitride (g-C3N4) with hydrogen peroxide (H2O2), and combined with high-temperature calcination treatment. The obtained 2-O-g-C3N4 catalyst exhibits high activity in visible light photocatalytic degradation of bisphenol A (BPA) with a mineralization rate as high as 62.3%. According to the characterization results of X-ray diffraction, transmission electron microscopy, UV-visible spectroscopy, Brunauer-Emmett-Teller and photoluminescence spectroscopy analyses, the markedly higher visible-light-driven oxidation activity of 2-O-g-C3N4 is attributed to the larger specific surface area, wider range of light responses and low charge recombination rate. Moreover, the trapping experiment shows that superoxide radicals (•O2−) are the dominant active species in the BPA decomposition process over 2-O-g-C3N4. This study presents a simple and environment-friendly method to synthesise oxygen-doped graphitic carbon nitride.
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Saxena, Mukul, Anuj Kumar Sharma, Ashish Kumar Srivastava, Rabesh Kumar Singh, Amit Rai Dixit, Akash Nag, and Sergej Hloch. "Microwave-Assisted Synthesis, Characterization and Tribological Properties of a g-C3N4/MoS2 Nanocomposite for Low Friction Coatings." Coatings 12, no. 12 (November 28, 2022): 1840. http://dx.doi.org/10.3390/coatings12121840.
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This study explores the tribological performance of microwave-assisted synthesized g-C3N4/MoS2 coatings. The two-dimensional transition metal dichalcogenide (TMD) nanosheet is getting prominence in the study of tribology due to its layered structure. The graphitic carbon nitride (g-C3N4) nanosheet was made using the calcination method and its nanocomposite with molybdenum disulfide (MoS2) was produced using a microwave-assisted method. The structure and morphology of the samples were characterized by some well-known methods, and tribological properties were studied by a pin-on-disc (POD) apparatus. Morphological analysis revealed that graphitic carbon nitride and molybdenum disulfide coexisted, and the layer structured MoS2 was well dispersed on graphitic carbon nitride nanosheets. BET analysis was used to determine the pore volume and specific surface area of the synthesized materials. The inclusion of MoS2 nanoparticles caused the composite’s pore volume and specific surface area to decrease. The reduction in g-C3N4 pore volume and specific surface area confirmed that the pores of calcinated graphitic carbon nitride were filled with MoS2 nanoparticles. The tribological property of g-C3N4/MoS2 nanocomposite was systematically investigated under different factors such as applied loads (5N to 15N), sliding speed (500 to 1000 mm/s) and material composition (uncoated, MoS2-coated, 9 wt.% of g-C3N4 and 20 wt.% of g-C3N4 in the composite). The optimal composite material ratio was taken 9%, by weight of g-C3N4 in the g-C3N4/MoS2 composite for a variety of levels of loads and sliding speeds. The results indicates that the incorporation of g-C3N4 in nanocomposites could reduce friction and improve wear life, which were better than the results with single MoS2. This study demonstrates a solution to broaden the possible uses of g-C3N4 and MoS2-based materials in the field of tribology.
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Jiang, Zhiqiang, Yirui Shen, and Yujing You. "Synthesis of Porous Carbon Nitride Nanobelts for Efficient Photocatalytic Reduction of CO2." Molecules 27, no. 18 (September 16, 2022): 6054. http://dx.doi.org/10.3390/molecules27186054.
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Sustainable conversion of CO2 to fuels using solar energy is highly attractive for fuel production. This work focuses on the synthesis of porous graphitic carbon nitride nanobelt catalyst (PN-g-C3N4) and its capability of photocatalytic CO2 reduction. The surface area increased from 6.5 m2·g−1 (graphitic carbon nitride, g-C3N4) to 32.94 m2·g−1 (PN-g-C3N4). C≡N groups and vacant N2C were introduced on the surface. PN-g-C3N4 possessed higher absorbability of visible light and excellent photocatalytic activity, which was 5.7 and 6.3 times of g-C3N4 under visible light and simulated sunlight illumination, respectively. The enhanced photocatalytic activity may be owing to the porous nanobelt structure, enhanced absorbability of visible light, and surface vacant N-sites. It is expected that PN-g-C3N4 would be a promising candidate for CO2 photocatalytic conversion.
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Starukh, Halyna, and Petr Praus. "Doping of Graphitic Carbon Nitride with Non-Metal Elements and Its Applications in Photocatalysis." Catalysts 10, no. 10 (September 28, 2020): 1119. http://dx.doi.org/10.3390/catal10101119.
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This review outlines the latest research into the design of graphitic carbon nitride (g-C3N4) with non-metal elements. The emphasis is put on modulation of composition and morphology of g-C3N4 doped with oxygen, sulfur, phosphor, nitrogen, carbon as well as nitrogen and carbon vacancies. Typically, the various methods of non-metal elements introducing in g-C3N4 have been explored to simultaneously tune the textural and electronic properties of g-C3N4 for improving its response to the entire visible light range, facilitating a charge separation, and prolonging a charge carrier lifetime. The application fields of such doped graphitic carbon nitride are summarized into three categories: CO2 reduction, H2-evolution, and organic contaminants degradation. This review shows some main directions and affords to design the g-C3N4 doping with non-metal elements for real photocatalytic applications.
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Rodmuang, Sirirat, Raweewan Plairaharn, Kanokwan Teingtum, Suntree Sangjan, and Orawan Chunhachart. "Effect of Ag/ZnO-Graphitic Carbon Nitride on Antimicrobial Activity under Visible Light." Key Engineering Materials 858 (August 2020): 116–21. http://dx.doi.org/10.4028/www.scientific.net/kem.858.116.
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Zinc oxide-graphitic carbon nitride (ZnO/g-C3N4) composites were synthesized by precipitation method in order to improve photocatalytic activity under visible light. To enhance antimicrobial activity, silver was added into zinc oxide-graphitic carbon nitride (Ag/ZnO/g-C3N4). Ultrastructures of the composite were analyzed by X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Photocatalytic activity of the composites was carried out by degradation of methylene blue solution as a function of contact time. The results revealed that ZnO/g-C3N4 was capable of dye degradation at 96.65%. Addition of Ag into ZnO/g-C3N4 resulted in increase of dye reduction rate. For antibacterial test, Ag/ZnO/g-C3N4 exhibited bactericidal activity against Pseudomonas aeruginosa and Bacillus cereus. For antifungal test, Ag/ZnO/g-C3N4 showed resistance to Aspergillusniger for 7 days. Ag/ZnO-g-C3N4 composite exhibited better photocatalytic and antimicrobial activities compare to ZnO and g-C3N4. These results indicate that precipitation method is a cheap, rapid and efficient method that can be used to synthesize Ag/ZnO-g-C3N4 composites. For further studies, applications of this Ag/ZnO-g-C3N4 composites in microbiological and agricultural fields will be carried out.
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Wang, Shun, Dongdong Lou, Zhaojie Wang, Nuo Yu, Haifeng Wang, Zhigang Chen, and Lisha Zhang. "Synthesis of ultrathin g-C3N4/graphene nanocomposites with excellent visible-light photocatalytic performances." Functional Materials Letters 12, no. 03 (May 16, 2019): 1950025. http://dx.doi.org/10.1142/s1793604719500255.
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Graphitic carbon nitride (g-C3N[Formula: see text] has drawn increasing interest as an efficient photocatalyst. To further improve its photocatalytic activity, herein we coupled g-C3N4 with graphene to construct ultrathin g-C3N4/graphene (g-C3N4/G) nanocomposites by a pyrolysis-sonication-hydrothermal method. Under the illumination of visible-light, g-C3N4/G nanocomposites with 10[Formula: see text]wt.%G can degrade 92% Rhodamine B (RhB) in 120[Formula: see text]min, which is higher than that (57%) from pure g-C3N4. Moreover, the recycling experiment indicates that the nanocomposite still remains excellent photocatalytic stability. Therefore, g-C3N4/G nanocomposites exhibit excellent photocatalytic activity and stability, resulting in a promising application in water purification.
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Zabielaite, Ausrine, Aldona Balciunaite, Daina Upskuviene, Jurate Vaiciuniene, Vitalija Jasulaitiene, Loreta Tamasauskaite-Tamasiunaite, and Eugenijus Norkus. "Cobalt Nanoparticles Supported Graphitic Carbon Nitride Electrocatalyst for Oxygen Reduction." ECS Meeting Abstracts MA2022-01, no. 35 (July 7, 2022): 1493. http://dx.doi.org/10.1149/ma2022-01351493mtgabs.
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This study is focused on the fabrication of cobalt nanoparticles supported graphitic carbon nitride (CoNPs-g-C3N4) by microwave synthesis and their application for oxygen reduction reaction (ORR). X-ray photoelectron spectroscopy (XPS), Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) were employed to characterize the prepared catalysts. The electrocatalytic activity of CoNPs-g-C3N4 for ORR was investigated using the rotating disk electrode technique in 0.1 M KOH solution. It has been determined that the g-C3N4, prepared by annealing melamine at a temperature of 520 oC for two h, had a high nitrogen content of 67.92 at.%. The data of the oxygen reduction on the CoNPs-g-C3N4 catalysts with different Co loadings and under various conditions are presented. Compared to the metal-free g-C3N4, the doping of g-C3N4 with CoNPs enhances the electrocatalytic activity and the selectivity towards the 4e- reduction reaction of O2 to H2O. Acknowledgment This project has received funding from European Social Fund (project No. 09.3.3-LMT-K-712-23-0188) under a grant agreement with the Research Council of Lithuania (LMTLT).
Dissertations / Theses on the topic "Graphitic carbon nitride (g-C3N4)"
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Adekoya, Oluwatobi. "Design and Synthesis of Graphitic Carbon Nitride (g-C3N4) Based Materials for Rechargeable Batteries." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/401444.
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Carbon nitrides are a unique family of nitrogen-rich carbon materials with multiple beneficial properties for effective alkali metal ion transport/storage. Graphitic carbon nitride (g-C3N4) is considered the most viable member of the carbon nitride family because of its high nitrogen content, wide structure with several nitrogen-defect pore sites, ease of synthesis, affordability, and scalability. Also, g-C3N4 delivers a lithium ion battery (LIBs) theoretical capacity of 524 mAh/g unlike graphite which records only 327 mAh/g. However, due to the ineffective intercalation/deintercalation reaction of Li+ with C3N4 it suffers low capacity, poor conductivity and structural deformation when applied as an anode material for battery application. Due to this problem, the application of g-C3N4 for LIBs has slowed down, and the prospects of g-C3N4 for emerging battery systems such as potassium ion batteries (KIBs) have not been explored. In this thesis, we present unique strategies to resolve the problems of irreversible Li+ intercalation, poor conductivity, and structural destruction, and explore g-C3N4-based composites for KIB system.
In the first study, one-dimensional carbon nitride nanofibers were designed and proved to be a more effective and better performing anode material for LIBs than bulk g-C3N4. This work was accomplished by combining theoretical computing and experimental techniques, Density functional theory calculation showed that the edges of the 1D-g- C3N4 nanofibers exhibited a suitable Li adsorption energy for stress-free adsorption and desorption of adsorbed Li-atoms. Moreover, our synthesized 1D-g-C3N4 nanofiber possessed edges and pores, as well as higher pyridinic nitrogen content unlike the bulk g-C3N4. The 1D-g-C3N4 nanofiber delivered a superior specific capacity of 181.7 mAh/g, a specific capacity of 138.6 mAh/g after 5000 cycles when cycled at 10C along with excellent stability and power density. This performance remains the highest amongst reported C3N4 anode materials in literature.
Carbon nitride/graphene (C3N4/graphene) heterostructure is commonly reported for lithium ion batteries and this heterostructure design occurs in different configurations of 1D/2D or 2D/2D. However, a clear theoretical understanding of how the configuration of such heterostructure affects battery performance is not established. By using a first principle theory approach we studied the 1D/2D and 2D/2D C3N4/graphene heterostructures with a focus on their conductivity, charge transfer, bond structure and rearrangement/breakage and theoretical reversible capacity. In all our study, the DFT results showed that 1D/2D C3N4/graphene delivers superior charge transfer, electronic conductivity, theoretical capacity, and structural integrity compared to 2D/2D configuration. This work expanded upon the relationship between the heterostructure configuration and the electrochemical performance, this work will encourage the design of effective heterostructures for rechargeable batteries.
Motivated by the result of the 1D/2D C3N4/graphene heterostructure for LIBs, we employed it for potassium ion battery application. When the fabricated 1D-g-C3N4 nanofiber was employed in potassium ion batteries, the high nitrogen content facilitated K+ adsorption; however, the K-atom diffusion barrier was too high for effective adsorption/desorption. Therefore, we combined the 1D-g-C3N4 nanofiber with 2D reduced graphene oxide (rGO) to design a 1D/2D C3N4/rGO composite for stable and effective potassium storage. In this work, we also combined the use of Density Functional Theory calculations and experimental battery testing along with high powered characterization techniques to study the storage mechanism of the composite electrode material for potassium ion battery. The 1D/2D composite benefitted from the larger surface area and conductivity of 2D reduced graphene oxide and the nitrogen rich active sites of the 1D-g-C3N4 nanofiber. Additionally, DFT calculations showed that the graphene structure from 2D rGO possessed lower K-atom diffusion barrier and superior conductivity which provided shorter ionic transport distances and boosted electronic conductivity in the composite. Thanks to the synergistic interaction between the 1D-g-C3N4 nanofiber and 2D rGO, the electrode delivered a remarkable specific capacity of 464.9 mAh/g after 200 cycles at 1 A/g and 228.6 mAh/g after 1000 cycles at 10 A/g, which is one of the best potassium ion battery anode material performance reported so far.
Another approach to exploring the benefits of the 1D-g-C3N4 nanofiber is to use it as a source of N-doped carbon. Metal oxides such as cobalt oxide (Co3O4) have been widely applied as anode materials in rechargeable LIBs but the small d-spacing limits their application for large-sized metal ion batteries such as potassium ion batteries. Moreover, through DFT calculations we proved that the poor performance of Co3O4 for KIBs is due to poor conductivity, high diffusion barrier, and weak potassium interaction. Thanks to the concept of interfacial engineering, we fabricated a hierarchical composite of Co3O4@N-doped carbon in which the N-doped carbon is derived from 1D-g-C3N4. The material design approach for the composite involved coating the surface of Co3O4 with N-doped carbon such K+ can be effectively transported through the that at the interface both materials via multiple ionic pathways. Furthermore, the structural design of the composite enabled increased Co3O4 spacing for effective K+ diffusion, improved conductivity, and protection of the core structure from damage. Based on the entire composite, a capacity of 448.7 mAh/g was delivered after 40 cycles, and 213 mAh/g was retained after 740 cycles when cycled at 500 mA/g. This work combined the principle of material boundary engineering with theoretical computation to design a composite anode material whose performance exceeded that of most metal-oxide-based KIB anodes reported in literature.
In summary, the strategies presented in this thesis show that the morphology and electronic properties of g-C3N4 can be manipulated to resolve the problems of irreversible intercalation/deintercalation, poor conductivity, and structural deformation. Moreover, the application of g-C3N4 has been extended to potassium ion batteries and we are the first research group to demonstrate this in literature. Also, the electrochemical performances recorded from experimental battery testing and theoretical computation (DFT simulation) shows that g-C3N4 and g-C3N4-based materials are promising advanced anode materials for LIBs and KIBs. These strategies can be extended to other members of the carbon nitride family such as CN, C2N, C3N etc. for different metal-ion batteries.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Li, Yibing. "Graphitic Carbon-Based Functional Nanomaterials for Environmental Remediation and Energy Conversion Applications." Thesis, Griffith University, 2015. http://hdl.handle.net/10072/366091.
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Carbon-based nanomaterials have attracted significant attention due to their unique optical, electrical, thermal and mechanical properties. In recent years, a large number of carbon-based nanomaterials have been investigated including carbon nanotubes, graphitic carbon nitride (g-C3N4), graphene, carbon nanofibers, carbon nanodots (CNDs), heteroatom-doped carbon, and carbon-based materials obtained from biomass etc. The unique and superior properties of such carbon-based materials make them useful for a wide range of applications in the fields such as environmental remediation and energy conversions. Although significant progress has been made over the past decade or so, few drawbacks of carbon-based materials still remain unresolved. For example, as a photocatalyst, the weak van der Waals interactions between adjacent conjugated planes of g-C3N4 and poor electronic properties affect negatively on the photocatalytic activity. Despite a variety of synthetic methods have been investigated, to fabricate undoped and doped carbon-based materials, the efficiency and level of control on the resultant products are far from satisfactory. Majority of these approaches either involve tedious and complex experimental procedures or require using harsh reaction conditions, or possessing low yield production. Furthermore, to achieve heteroatom-doped carbon-based materials, the reported approaches almost exclusively require the use of synthetic chemicals as carbon and heteroatom sources, respectively. The large-scale application of fuel cells and dye-sensitized solar cells (DSSCs) using Pt-based catalysts is hindered by the inherent disadvantages of Pt such as high cost, scarcity and low resistance to crossover effect of methanol molecule. It is therefore highly desirable to realize heteroatom doping by simple, low-cost, high yield and environmentally benign synthesis methods for fabrication of commercially viable carbon-based materials for applications in solar cells and fuel cells.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
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Liu, Mengdi. "Ta₃N₅/Polymeric g-C₃N₄ as Hybrid Photoanode for Solar Water Splitting:." Thesis, Boston College, 2018. http://hdl.handle.net/2345/bc-ir:108366.
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Thesis advisor: Dunwei WangWater splitting has been recognized as a promising solution to challenges associated with the intermittent nature of solar energy for over four decades. A great deal of research has been done to develop high efficient and cost-effective catalysts for this process. Among which tantalum nitride (Ta₃N₅) has been considered as a promising candidate to serve as a good catalyst for solar water splitting based on its suitable band structure, chemical stability and high theoretical efficiency. However, this semiconductor is suffered from its special self-oxidation problem under photoelectrochemical water splitting conditions. Several key unique properties of graphitic carbon nitride (g-C₃N₄) render it an ideal choice for the protection of Ta₃N₅. In this work, Ta₃N₅/g-C₃N₄ hybrid photoanode was successfully synthesized. After addition of co-catalyst, the solar water splitting performance of this hybrid photoanode was enhanced. And this protection method could also act as a potential general protection strategy for other unstable semiconductors
Thesis (MS) — Boston College, 2018
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
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Fina, Federica. "Metal loaded g-C₃N₄ for visible light-driven H₂ production." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6322.
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The need for green and renewable fuels has led to the investigation of ways to exploit renewable resources. Solar among all the renewables is the most powerful and its conversion into usable energy would help in solving the energy problem our society is facing. Photocatalytic water splitting for hydrogen production is an example of solar energy storage into chemical bonds. The hydrogen produced in this way can then be employed as carbon free fuel creating the “Hydrogen Cycle”. This work investigates the structure and the activity of graphitic carbon nitride (g-C₃N₄), an organic semiconductor that proved a suitable photocatalyst for hydrogen production from water. Synthesised by thermal polycondensation of melamine it is a graphitic like material with a band gap of 2.7 eV which makes it a visible light active catalyst. In a first instance the effect of the synthesis conditions on its structure and morphology are investigated to find the optimum parameters. The temperature of condensation is varied from 450°C up to 650°C and the length from 2.5 h to 15 h. The structural changes are monitored via X-ray diffraction (XRD) and elemental analysis while the effect on the morphology and the band gap of g-C₃N₄ are investigated by mean of scanning electron microscopy and UV-Vis absorption. Subsequently, a study of the crystal structure of the catalyst is carried out. Using structures proposed in the literature, X-ray diffraction and neutron scattering simulations are used to narrow down the number of possible 3D structures. After structural characterisation, the activity of g-C₃N₄ for photocatalytic hydrogen evolution is evaluated. It is confirmed that loading 1 wt.% Pt on its surface significantly increases the hydrogen evolution rate. The attention then focuses on the loading procedures, the reduction pre treatments of the co-catalyst and the reasons of the different performances when different procedures are employed. The catalytic system is characterised by mean of X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and XRD. By investigating the composition and the morphology of the platinum nanoparticles under different conditions, the main factors responsible for the changes in activity of g-C₃N₄ for hydrogen evolution are identified. Additionally, the role of the co catalyst and its interaction with g-C₃N₄ is also elucidated. Finally, taking forward the knowledge acquired on the Pt-g-C₃N₄ system, the effect on the hydrogen evolution rate of alloying platinum with a second metal (Cu, Ag, Ni and Co) is studied. The nanoparticles are characterised by XRD and TEM. A screening of the loading procedures and bimetallic systems is performed to identify the most promising for photocatalytic hydrogen evolution with the aim of bringing them towards further investigation.
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Lan, Phung Thi, and Nguyen Thi Kim Giang. "Study on synthesis of MoS2modified g-C3N4materials for treatment of Direct black 38 dye." Caprice Thomas, Abt. 3.3.3 Qucosa, 2018. https://tud.qucosa.de/id/qucosa%3A33074.
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Pure g-C3N4 and MoS2 modified g-C3N4 materials were synthesized using a facile heating method and a low-temperature hydrothermal method, respectively. The obtained samples were characterized by XRD pattern and N2 adsorption-desorption technique at 77K. The adsorption and photocatalytic performance of all obtained samples were investigated by discoloration of direct black 38 dye in the dark and under visible light irradiation. The results showed that all obtained samples exhibited good discoloration efficiency of direct black 38 dye. The two factors including pH values and Mo loading effected mainly on elimination efficiency of direct black 38 dye. MoS2 modified g-C3N4 materials possessed the more enhanced adsorption and photocatalytic performance in comparison to pure g-C3N4 at pH value of 3.5, with adsorbent dosage of 0.1 g/L. Furthermore, it was found that the adsorption process and photo-catalysis simultaneously occurred under visible light irradiation and followed up a pseudo-second-order kinetic reaction of Langmuir - Hinshelwood model.g-C3N4 và g-C3N4 biến tính bởi MoS2 đã được tổng hợp theo phương pháp nung đơn giản và phương pháp thủy nhiệt ở nhiệt độ thấp tương ứng. Các mẫu tổng hợp đã được đánh giá đặc trưng bởi các phương pháp hiện đại như giản đồ nhiễu xạ tia X, phương pháp hấp phụ-khử hấp phụ N2 ở 77K. Khả năng hấp phụ và quang hóa xúc tác của các vật liệu tổng hợp đã được nghiên cứu bởi quá trình phân hủy màu thuốc nhuộm direct black 38 trong điều kiện bóng tối và chiếu sáng bởi ảnh sáng nhìn thấy của đèn chiếu sáng sợi đốt wolfram (220V-100W). Các kết quả nghiên cứu chỉ ra rằng các mẫu tổng hợp đều có hiệu suất xử lý màu cao đối với thuốc nhuộm direct black 38. Hai yếu tố gồm pH dung dịch và hàm lượng MoS2 ảnh hưởng chính đến hiệu suất xử lý màu direct black 38. g-C3N4 biến tính bởi MoS2 luôn thể hiện hiệu suất hấp phụ và quang hóa cao hơn so với g-C3N4 tinh khiết. Hơn nữa, khi được chiếu sáng bởi ánh sáng nhìn thấy thì quá trình hấp phụ và quá trình quang hóa thuốc nhuộm direct black 38 trên các vật liệu tổng hợp đã xảy ra đồng thời và mô hình Langmuir - Hinshelwood động học bậc 2 đã được đề xuất cho quá trình này.
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Chu, Yi-Ching, and 朱怡親. "Photoelectrochemical Analysis of Multi-ion Doped Graphite Carbon Nitride (g-C3N4) and Its Application on Hydrogel Formation." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/7crvvu.
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碩士中原大學
化學工程研究所
107
Graphitic carbon nitride (g-C3N4) is a promising visible light-driven photocatalyst with a band gap energy of 2.70 eV. However, abundant surface defects and unwanted carbon or nitrogen vacancies may lead to high charge recombination that results in a decrease of photocatalytic activity. In this study, P and S were co-doped on oxygenated g-C3N4(PSOCN) using a thermal condensation method with different weight ratio of P and S (PxSyOCN, x, y =5,10,15). Photoelectrochemical properties including impedance spectroscopy, Mott-Schottky analysis, and photocurrent density, and the degradation of organic pollutants under visible light irradiation were investigated. XRD diffraction peaks of PSOCN located at 13.1° and 27.1° were assigned to (100) and (002) crystal plane of graphite-type carbon nitride (CN). The SEM images showed that both CN and PSOCN had irregular stacked shape and plate-like morphologies, indicated that doping were not affect the surface morphologies. In the UV-vis spectra, the absorption wavelength of PSOCN exhibited a shoulder at approximately 440-500 nm, and its band gap is a little smaller than that of CN. In Mott-Schottky test, PSOCN and CN samples are n-type semiconductors, and Fermi level of PSOCN all move to negative potential, indicating electronic of PSOCN are more easily moved to conduction band. Especially, P10S5OCN had the most large photocurrent density. In addition, PSOCN hydrogel was fabricated using photoinduced polymerization method. PSOCN hydrogel enables not only to decompose a commonly seen dye, methyl blue, but also to be recycled easily. In summary, P10S5OCN is the best weight ratio in PSOCN. Its photocurrent density is larger than others, and P10S5OCN hydrogel also has better degradation efficiency of methyl blue.
Book chapters on the topic "Graphitic carbon nitride (g-C3N4)"
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Razali, Nur Aqilah Mohd, Wan Norharyati Wan Salleh, Farhana Aziz, Ahmad Fauzi Ismail, and Wan Mohd Asyraf Wan Mahmood. "Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Wastewater Treatment." In Advanced Materials for Wastewater Treatment and Desalination, 3–23. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003167327-2.
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Mishra, Prashant Kumar, Ritu Malik, Vijay K. Tomer, and Nirav Joshi. "Hybridized Graphitic Carbon Nitride (g-CN) as High Performance VOCs Sensor." In Materials Horizons: From Nature to Nanomaterials, 285–302. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4810-9_11.
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Kharlamov, O., M. Bondarenko, G. Kharlamova, P. Silenko, O. Khyzhun, and N. Gubareni. "Carbon Nitride Oxide (g-C3N4)O and Heteroatomic N-Graphene (Azagraphene) as Perspective New Materials in CBRN Defense." In NATO Science for Peace and Security Series A: Chemistry and Biology, 279–92. Dordrecht: Springer Netherlands, 2018. http://dx.doi.org/10.1007/978-94-024-1304-5_20.
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Ezhumalai, Yamuna, Prabakaran Kumaresan, and Tirupathy Jayapalan. "Graphite Carbon Nitride." In Photocatalysts - New Perspectives [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.104976.
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Graphitic carbon nitride (g-C3N4), is a synthetic polymer made up of carbon, nitrogen, and some impurity hydrogen that is linked together using tris-triazine-based patterns. Because of the inclusion of N and H atoms, it has electron-rich characteristics, basic surface functions, and H-bonding motifs, compared to the bulk of carbon materials. Consequently, it’s seen as a possible replacement for carbon in material applications. A brief introduction to g-C3N4 is included in this chapter, as are the methods for synthesizing this material with various textural structures and surface morphologies, as well as its physicochemical properties. Furthermore, four parts of g-C3N4 applications are discussed. We anticipate that this work will motivate readers to look for new applications for this material in catalysis and other domains.
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Xavier, Marilyn Mary, and Suresh Mathew. "g-C3N4-based sensors." In Synthesis, Characterization, and Applications of Graphitic Carbon Nitride, 225–48. Elsevier, 2023. http://dx.doi.org/10.1016/b978-0-12-823038-1.00004-0.
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Ismael, Mohammed. "1 Hydrogen production via water splitting over graphitic carbon nitride (g-C3N4)-based photocatalysis." In Process Systems Engineering, 1–40. De Gruyter, 2022. http://dx.doi.org/10.1515/9783110705201-001.
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Sharma, S. "Graphitic Carbon Nitride based Photocatalytic Systems for High Performance Hydrogen Production: A Review." In Materials Research Foundations, 161–92. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901359-5.
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Pectin cerium(IV) iodate (PcCeI) and cerium(IV) iodate (CeI) cation ion exchange materials were synthesized via sol–gel methods. The materials were characterized by using Fourier transform infrared spectroscopy, X-ray diffractometer, thermogravimetric analysis, and scanning electron microscopy. The ion exchange capacity (IEC), thermal stability, distribution coefficient (Kd), and pH titrations were investigated to recognize the cation exchange behavior of the materials. The IEC of pectin-cerium(IV) iodate (PcCeI and cerium(IV) iodate CeI were reported as 1.80 meq/g and 0.92 meq/g, respectively. The higher distribution coefficient values of 250.01 and 219.14 mg/L confirmed the selectivity of pectin-cerium(IV) iodate hybrid ion exchanger for As3+ and Zn2+. The antibacterial activity of synthesized ion exchangers was explored for E. coli bacteria and observed relatively higher for PcCeI as compared to CeI.
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Kumar, A. "Structural Modifications of Carbon Nitride for Photocatalytic Applications." In Materials Research Foundations, 299–331. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901359-10.
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The current research on photocatalysis is totally focused on the designing and innovation of various low cost materials. For an efficient photocatalyst, there are some aspects which are to be assessed before practical use, such as optical activity, thermal and chemical stability, easy and availability of raw material, biocompatibility, etc. Fortunately, g-C3N4 offers most of these qualities to behave as a star photocatalyst. g-C3N4 could be easily prepared from low cost precursor materials such as urea, melamine, cyanimide and dicyandiamide by simple thermal treatment. Furthermore, larger surface area and two-dimensional planar conjugation structure of g-C3N4 can provide a large platform for anchoring various substrates. Various researchers have utilized g-C3N4 for varieties of applications such as green energy production, energy storage devices, biomedical application, wastewater treatment via photocatalysis and adsorption, photo sensors, etc. Although there are some disadvantages associated with use of g-C3N4 when utilized for various applications. To overcome such hitches various structural modifications have been applied to g-C3N4. The current chapter summarizes a wide mode of applications of g-C3N4 along with various structural modifications which were recently applied to improve the photocatalytic efficacy.
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Luo, Jingpeng, Weiying Pang, Qingying Ye, and Dong Fu. "Fe-Cu Bimetallic Oxide Quantum Dots Coupled with g-C3N4 Nanosheets for Efficient Photo-Fenton Degradation of Phenol." In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220343.
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Graphitized carbon nitride (g-C3N4), as a simple and green photocatalytic material, has been widely used in photocatalytic degradation. However, the photocatalytic activity of g-C3N4 was inhibited by poor visible light absorption and high photocarrier recombination rate. Metal quantum dots (Qds)/g-C3N4 nanosheets coupled catalysts have attracted more and more attention in the Fenton advanced oxidation process due to their high charge mobility and more active sites. In this work, heterogeneous photocatalysts of Fe-Cu bimetallic oxide quantum coupled with g-C3N4 nanosheets were prepared. It shows high activity in Fenton and photocatalytic system. Under the optimal conditions, the removal efficiency of 50 ppm phenol reached 99% after 60 min. The removal efficiency of the catalyst for phenol did not decrease significantly after four cycles of experiments, and the catalyst had good stability. The experimental results show that the synergy between g-C3N4 semiconductor photocatalytic oxidation technology and heterogeneous Fenton advanced oxidation technology has great practical significance.
Conference papers on the topic "Graphitic carbon nitride (g-C3N4)"
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Ola, Oluwafunmilola, and Yanqiu Zhu. "Two-Dimensional WS2/g-C3N4 Layered Heterostructures With Enhanced Pseudocapacitive and Electrocatalytic Properties." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23137.
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Abstract In this work, tungsten-based hybrid nanocomposites were grown on interconnected, macroscopic graphitic carbon nitride scaffold after solvothermal treatment followed by sulfidation to attain multifunctional composite electrocatalysts. The physicochemical properties of the obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The tungsten-based composites were tested as electrodes for pseudocapacitors and as electrocatalysts for hydrogen evolution reaction, to take advantage of their porous graphitic carbon nitride features which would be beneficial for optimal ion transport to tungsten-based nanoparticles. These unique physicochemical features endow these composites with excellent electrochemical performances to reach a current density of 10 mA/cm2 for the hydrogen evolution reaction. In addition to demonstrating excellent specific capacitance, these hybrid nanocomposites also possess good stability after 8 hours of testing.
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"Production of thermally stable alloyed carbon composite materials containing g-C3N4, β-Si3N4 and Si2N2O phases." In II All-Russian Scientific Conference "Science, Technology, Society". Krasnoyarsk Science and Technology City Hall, 2022. http://dx.doi.org/10.47813/nto.2.2022.5.14-25.
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The article proposes a technology for alloying nanostructured carbon material with Taunite nitrogen and silicon, combining mechanochemical synthesis in a spherical planetary mill and multistage heat treatment up to 1100°C. Mechanochemical methods of processing carbon material make it possible to obtain structural-phase states in it containing metastable phases and amorphous (non-crystalline) structures that cannot be realized by other methods. The selected processing parameters contribute to achieving a uniform phase distribution in the synthesized carbon composite material. The combination of mechanochemical methods and subsequent annealing becomes an alternative basis for the technology of obtaining alloyed carbon composite materials containing phases of silicon nitride and oxynitride. The main technological task in creating such a material is to achieve the necessary balance to maintain a certain balance between the phases: carbon - silicon nitride - silicon oxynitride - phases of alloying elements. The phase composition of the obtained samples was investigated by X-ray diffractometry, the porosity and distribution of chemical elements in the samples of the obtained material was estimated using X-ray tomography and scanning electron microscopy. Based on the results obtained, conclusions are formulated about the formation of phases of graphite-like carbonitride, nitride and oxynitride of silicon in a thermally stable nanocarbon material.
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Ong, Wee-Jun. "Graphitic Carbon Nitride (g-C3N4)-Based Nanocomposites for Artificial Photosynthesis toward Renewable Energy Production." In The 7th International Multidisciplinary Conference on Optofluidics 2017. Basel, Switzerland: MDPI, 2017. http://dx.doi.org/10.3390/optofluidics2017-04265.
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Acquaviva, S., E. D’Anna, M. L. De Giorgi, G. Leggieri, A. Luches, M. Martino, A. Perrone, and A. Zocco. "Carbon Nitride Films Synthesis and Deposition by Excimer Laser Ablation of Graphite Targets in Nitrogen Atmosphere." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.cmf3.
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The prediction of a covalently bound carbon nitride solid β-C3N4 [1], with characteristics comparable to or even better than those of diamond, stimulated many attempts to synthesize and deposit thin carbon nitride films. In spite of almost a decade of search, this material has not yet been synthesized in stoichiometric phase. Nevertheless, it poses interesting issues about formation processes, C-N bonding states and CNx film properties. Ion/atomic beam assisted depositions are most frequently used. We are obtaining good results by using the simple technique of reactive laser ablation [2].