A metal-free photocatalytic hydrogen evolution system was successfully fabricated using heteroatom doped graphene materials as electron-transfer co-catalysts and carbon nitride as a semiconductor. The catalytic role o...A metal-free photocatalytic hydrogen evolution system was successfully fabricated using heteroatom doped graphene materials as electron-transfer co-catalysts and carbon nitride as a semiconductor. The catalytic role of graphene is significantly dependent on the heteroatom dopant of the graphene, such as O, S, B, N doped/undoped graphene co-catalysts, and N-graphene shows the best catalytic hydrogen evolution rate.展开更多
A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in ter...A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in terms of sodium pentachlorophenol（PCP-Na） decomposition and mineralization. The structural and physicochemical properties of these nanocomposites were characterized by X-ray diffraction, N2adsorption–desorption, transmission electron microscopy, scanning electron microscopy, Ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectra, and Fourier-transform infrared spectroscopy. The graphene–TiO2nanocomposites exhibited higher photocatalytic efficiency than commercial P25 for the degradation of PCP-Na, and 63.4% to 82.9% of the total organic carbon was fully mineralized. The improved photocatalytic activity may be attributed to the accelerated interfacial electron-transfer process and the significantly prolonged lifetime of electron-hole pairs imparted by graphene sheets in the nanocomposites. However,excessive graphene and the inhomogeneous aggregation of TiO2 nanoparticles may decrease photodegradation efficiency.展开更多
Zinc telluride/reduced graphene oxide （ZnTe/RGO） nanocomposites are synthesized by a one-pot, facile, solvothermal process using hydrazine hydrate as the reducing agent. Hydrazine hydrate not only promoted the forma...Zinc telluride/reduced graphene oxide （ZnTe/RGO） nanocomposites are synthesized by a one-pot, facile, solvothermal process using hydrazine hydrate as the reducing agent. Hydrazine hydrate not only promoted the formation ofZnTe nanoparticles but also reduced GO to RGO. The formation of ZnTe/RGO is demonstrated by different techniques. In addition, the experimental results suggest a possible formation mechanism of these nanocomposites. Finally, due to the transfer of the photo-generated electrons between ZnTe and RGO resulting in low electrons/holes recombination, the as-prepared nanocomposites of ZnTe/RGO exhibited strongly enhanced photocatalytic activity for the bleaching of methyl blue （MB） dye under visible light irradiation.展开更多
文摘A metal-free photocatalytic hydrogen evolution system was successfully fabricated using heteroatom doped graphene materials as electron-transfer co-catalysts and carbon nitride as a semiconductor. The catalytic role of graphene is significantly dependent on the heteroatom dopant of the graphene, such as O, S, B, N doped/undoped graphene co-catalysts, and N-graphene shows the best catalytic hydrogen evolution rate.
基金supported by the National Natural Science Foundation of China (No. 41371472)
文摘A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in terms of sodium pentachlorophenol（PCP-Na） decomposition and mineralization. The structural and physicochemical properties of these nanocomposites were characterized by X-ray diffraction, N2adsorption–desorption, transmission electron microscopy, scanning electron microscopy, Ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectra, and Fourier-transform infrared spectroscopy. The graphene–TiO2nanocomposites exhibited higher photocatalytic efficiency than commercial P25 for the degradation of PCP-Na, and 63.4% to 82.9% of the total organic carbon was fully mineralized. The improved photocatalytic activity may be attributed to the accelerated interfacial electron-transfer process and the significantly prolonged lifetime of electron-hole pairs imparted by graphene sheets in the nanocomposites. However,excessive graphene and the inhomogeneous aggregation of TiO2 nanoparticles may decrease photodegradation efficiency.
基金financially supported by the National Natural Science Foundation of China (Nos. 11164026, 51172193, 11504313, 51362026)the Natural Science Foundation for Distinguished Young Scholars of Xinjiang (No. 2013711007)
文摘Zinc telluride/reduced graphene oxide （ZnTe/RGO） nanocomposites are synthesized by a one-pot, facile, solvothermal process using hydrazine hydrate as the reducing agent. Hydrazine hydrate not only promoted the formation ofZnTe nanoparticles but also reduced GO to RGO. The formation of ZnTe/RGO is demonstrated by different techniques. In addition, the experimental results suggest a possible formation mechanism of these nanocomposites. Finally, due to the transfer of the photo-generated electrons between ZnTe and RGO resulting in low electrons/holes recombination, the as-prepared nanocomposites of ZnTe/RGO exhibited strongly enhanced photocatalytic activity for the bleaching of methyl blue （MB） dye under visible light irradiation.
