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PVP assisted hydrothermal synthesis of CuCoO2 nanoplates with enhanced oxygen evolution reaction performance
摘要： Tuning size and morphology and exploiting new catalytic materials are several important strategies commonly used to develop highly efficient oxygen evolution reaction (OER) electrocatalysts. In this work, we report the synthesis of CuCoO2 (CCO) nanoplates through a facile one-step PVP assisted hydrothermal process. The influence of hydrothermal reaction parameters, including the precursor composition, reaction temperature and duration, on the morphology, size and crystal phase of CCO crystals has been investigated in detail. In addition, X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have been used to comprehensively characterize CCO’s crystal structure, morphology, composition and chemical states of elements. Furthermore, the electrocatalytic performance of CCO nanoplates towards the OER is studied and compared to that of CCO micrometer-sized crystals. The CCO nanoplates only require a low overpotential of 390 mV to attain an anodic current density 10 mA cm-2 in alkaline solution, and show comparatively fast OER kinetics with a Tafel slope of 70 mV dec-1 and reasonably good long-term catalytic stability, substantially outperforming CCO micro-crystals, which highlights the importance of size and morphology of CCO for use in OER electrocatalysis.
关键词： Water splitting,Oxygen evolution reaction,CuCoO2,Delafossite,Electrocatalyst
更新于2025-09-10 09:29:36
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Enhanced Oxygen Evolution Reaction Activity of Nanoporous SnO <sub/>2</sub> /Fe <sub/>2</sub> O <sub/>3</sub> /IrO <sub/>2</sub> Thin Film Composite Electrodes with Ultralow Noble Metal Loading
摘要： A conductive SnO2 layer and small quantities of IrO2 surface cocatalyst enhance the catalytic efficiency of nanoporous Fe2O3 electrodes in the oxygen evolution reaction at neutral pH. Anodic alumina templates are therefore coated with thin layers of SnO2, Fe2O3, and IrO2 by atomic layer deposition. In the first step, the Fe2O3 electrode is modified with a conductive SnO2 layer and submitted to different postdeposition thermal treatments in order to maximize its catalytic performance. The combination of steady-state electrolysis, electrochemical impedance spectroscopy, X-ray crystallography, and X-ray photoelectron spectroscopy demonstrates that catalytic turnover and e? extraction are most efficient if both layers are amorphous in nature. In the second step, small quantities of IrO2 with extremely low iridium loading of 7.5 μg cm?2 are coated on the electrode surface. These electrodes reveal favorable long-term stability over at least 15 h and achieve maximized steady-state current densities of 0.57 ± 0.05 mA cm?2 at η = 0.38 V and pH 7 (1.36 ± 0.10 mA cm?2 at η = 0.48 V) in dark conditions. This architecture enables charge carrier separation and reduces the photoelectrochemical water oxidation onset by 300 mV with respect to pure Fe2O3 electrodes of identical geometry.
关键词： iridium oxide,water splitting,nanostructures,iron oxide,atomic layer deposition
更新于2025-09-10 09:29:36
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Recent development of g-C3N4-based hydrogels as photocatalysts: A minireview
摘要： Solar-driven photocatalysis using graphitic carbon nitride (g-C3N4) is considered the most promising approach for the generation of H2 from water, degradation of organic pollutants, and reduction of CO2. However, bulk g-C3N4 exhibits several drawbacks, such as low specific surface area, high defect density, and fast charge recombination, which result in low photocatalytic performance. Construction of 3D porous hydrogels for g-C3N4 through nanostructural engineering is a rapid, feasible, and cost-effective technique to improve the adsorption capability, stability, and separability of the hydrogel composite; to increase the number of active sites; and to create an internal conductive path for facile charge transfer and high photocatalytic activity. This minireview summarizes the recent progresses in photocatalytic water splitting and dye degradation using g-C3N4-based hydrogels with respect to the state-of-the-art methods of synthesis, preparation, modification, and multicomponent coupling. Furthermore, comprehensive outlooks, future challenges, and concluding remarks regarding using g-C3N4-based hydrogels as highly efficient photocatalysts are presented.
关键词： water splitting,hydrogels,photocatalysts,dye degradation,g-C3N4
更新于2025-09-10 09:29:36
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Rationally Designed Copper-Modified Polymeric Carbon Nitride as a Photocathode for Solar Water Splitting
摘要： Polymeric carbon nitride has been considered an active photocathode for catalyzing H2 generation via water splitting. However, the application of the material in photoelectrochemical cells remains a challenge owing to the intrinsically sluggish kinetics of charge separation. Here, we developed a facile salt melt method for fabricating Cu-modified polymeric carbon nitride as an effective photocathode material for solar water splitting. Various characterization data confirm that Cu-modified polymeric carbon nitride contains both free CuCl derived from precursors and coordinated Cu species incorporated into the polymeric carbon nitride, which can generate type-II heterojunctions. This special heterojunction energy structure could contribute to significantly enhanced photocurrent density for hydrogen evolution. The proposed strategy for synthesizing of the Cu-modified polymeric carbon nitride can stimulate research into developing highly efficient visible-light active photocathodes.
关键词： photoelectrochemical,solar,water splitting,photocathode,coordination effect
更新于2025-09-10 09:29:36
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Fabrication of photoactive CaTiO3–TiO2 composite thin film electrodes via facile single step aerosol assisted chemical vapor deposition route
摘要： CaTiO3–TiO2 composite oxide films have been employed, for the first time, as photoelectrodes in photoelectrochemical (PEC) splitting of water. The transparent methanol solutions of Ti(Pro)4 and newly synthesized calcium complex [Ca2(TFA)3(OAc)(PrOH)(H2O)(THF)3] (1) (where TFA stands for trifluoroacetato; OAc stands for acetate; and PrOH stands for isopropanol) were utilized for aerosol assisted chemical vapor deposition (AACVD) of the target films. The composite electrodes were deposited on fluorine doped tin oxide (FTO) coated conducting glass substrates at varying deposition temperatures of 500–600 °C. The resulting films were extensively characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis and scanning electron microscopy. PEC responses of all the composite electrodes were studied under simulated solar irradiation of AM 1.5 G (100 mW cm?2). The CaTiO3–TiO2 photoanode formed at 600 °C showed higher photocurrent density of 610 μA cm?2 at 0.7 V versus Ag/AgCl/3 M KCl reference electrode as compared to the other two electrodes fabricated similarly with only difference of fabrication temperature (i.e., 500 and 550 °C).
关键词： photoelectrodes,photoelectrochemical water splitting,aerosol assisted chemical vapor deposition,CaTiO3–TiO2 composite
更新于2025-09-10 09:29:36
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Study on the visible-light photocatalytic performance of Ag3PO4/Cu2O composite
摘要： Ag3PO4/Cu2O composites were prepared by a facile wet chemical method. The specimens were examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and UV–Vis diffuse reflectance spectroscopy. The specimens exhibited an excellent photocatalytic activity on the degradation of RhB than pure Ag3PO4 and Cu2O. Furthermore, the photocatalyst specimen was found to exhibit higher efficiency in hydrogen conversion. It was found that a 30? wt% Ag3PO4-loaded specimen showed an excellent hydrogen generation performance. The excellent photocatalytic activity was ascribed to the separation of e–h pairs via the Z-scheme method composed of Ag, Ag3PO4 and Cu2O. This study demonstrated the potential approach to the photocatalytic splitting water to release hydrogen as well as the environmental purification of organic pollutants under visible-light irradiation.
关键词： Cuprous oxide,Z-scheme,Photocatalysis,Water splitting
更新于2025-09-10 09:29:36
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Enhanced Electron Transport in Rutile TiO2 Nanowires via H2S-Assisted Incorporation of Dissolved Silicon for Solar-Driven Water Splitting
摘要： Si-doping is an effective approach to enhance the electron transport and the photocatalytic activity of photocatalyst. In this study, for the first time the silicate glass such as fluorine-doped tin oxide (FTO) glass substrate is used as the silicon source for preparing Si-doped TiO2 photoanodes. First, the rutile TiO2 nanowires (NWs) were grown on FTO glass substrates by hydrothermal reaction, accompanying with the gradual dissolution of glass to generate soluble Si dopant incorporated into TiO2 NWs. Second, the TiO2 NWs were reduced to form the Ti3+ by H2S reduction. Finally, the Si-doped TiO2 photoanodes with higher doping density was obtained by calcination. The visible photocatalytic activity of Si-doped TiO2 NWs photoanode towards water splitting increased about three times as compared with pure TiO2 NWs. Reduction by H2S resulted in the enhanced electron transport and massive increase in charge-carrier density. This work provides a novel paradigm for silicon doping in materials for accelerating their carrier transport and applications.
关键词： Charge transport,Titanium dioxide,Silicon doping,Hydrothermal reaction,Water splitting
更新于2025-09-10 09:29:36
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A true oxygen-linked heptazine based polymer for efficient hydrogen evolution
摘要： O-doped/functional g-CN polymers are promising material which has been reported to modify inherent electronic structure and light harvest ability of the g-C3N4 based photocatalysts. However, the doping position and concentration of hetero atom remains ill-defined although enhanced photocatalytic activity of modified g-CN photocatalysts has been reported. Herein, a facile two step procedure to synthesize heptazine polymer with defined O-atom position in polymer structure is presented. Cyameluric acid, a member of cyamelurine family upon polycondensation under inert atmosphere ensures the insertion of O-atom at bridge position between heptazine units in growing polymer. The developed polymer OLHP (oxygen linked heptazine polymer) attains high hydrogen production efficiency likely due to high O-content and efficient charge separation evident from PL spectra compared to g-CN. This heptazine based precursor design also eliminates the possibility of presence of triazine based moiety defects in g-C3N4 polymers.
关键词： Water splitting,Heterogeneous photocatalysis,Cyameluric acid,Heptazine,carbon nitride
更新于2025-09-10 09:29:36
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Two-dimensional CdS/g-C6N6 heterostructure used for visible light photocatalysis
摘要： We have calculated and discussed the electronic and optical properties of two-dimensional (2D) CdS/g-C6N6 heterostructures by using hybrid density functional of HSE06. The CdS and g-C6N6 can form CdS/g-C6N6 heterostructures through weak van der Waals (vdW) interactions. The CdS/g-C6N6 composites are indirect bandgap semiconductors and type-II heterostructures. The visible light absorbtion of CdS/g-C6N6 composites is obviously improved, and the band alignment is bene?cial for spontaneous water redox reactions. Furthermore, the electrons migrating from CdS layer to g-C6N6 leads to the built-in electric ?eld formation, which promotes the e?ective separation of photogenerated carriers. These factors imply CdS/g-C6N6 composites are promising visible light water-splitting photocatalysts.
关键词： CdS/g-C6N6,Hybrid density functional,Photocatalytic water-splitting,Heterostructure
更新于2025-09-10 09:29:36
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[Nanostructure Science and Technology] Nanowire Electronics || X-Ray Spectroscopic Analysis of Electronic Properties of One-Dimensional Nanostructured Materials
摘要： Recent studies of the control of the shape and size of nanomaterials have enabled researchers to explore the development of energy storage and conversion applications in unprecedented detail. Nanomaterials can be exploited into green energy strategies if their surface architectures can be controlled by various treatment processes. Their remarkable behaviors arise in part from their small size, large surface area, and quantum con?nement. Nanomaterial science has various implications for environmental science and sustainability. Physical and chemical routes for controlling morphologies, crystal structures, and physical and chemical properties can be exploited to improve performance, expand the function, and extend lifetime of devices with energy storage and conversion applications. Such devices that involve nanomaterials include storage and conversion devices (energy storage, hydrogen generation, water-splitting and dye-sensitized solar cells (DSSC)), optical and electronic devices (semiconductors, photoelectrocatalytic, and waveguides), and environmental devices (sensors and adsorption/separation), among others. Such applications typically rely on emerging electrode designs, which support the realization of energy storage and conversion devices, whose manufacture can be done more ef?ciently by nanotechnology. The unique features of nanomaterials have been in the development of energy storage and conversion proved to be useful.
关键词： supercapacitors,nanomaterials,conversion,water-splitting,X-ray absorption spectroscopy,energy storage,MnO2,TiO2
更新于2025-09-10 09:29:36