A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au ...A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts were characterized by X-ray diffraction(XRD),transmission electron microscope(TEM),X-ray photo-electron spectroscopy(XPS),UV–vis diffuse reflectance spectra(UV–vis),Fourier transform infrared spectroscopy(FTIR),photoluminescence(PL),photocurrent response(I-t),and electrochemical impedance spectroscopy(EIS).The HRTEM images revealed that an intimate interface in composites were formed.The optimum photocatalytic activity of Rhodamine B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was about 9.7 times and 13.1 times as high as those of Bi_(2)MoO_(6) and g-C_(3)N_(4),respectively.The notably improved photocatalytic activity of Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au could be mainly ascribed to the abundant active sites and the enhanced separation efficiency of photogenerated carriers in Bi_(2)MoO_(6)/g-C_(3)N_(4) S-scheme system.Notably,Au nanoparticles could act as a co-catalyst to further promote electron transfer and separation from the conduction band of g-C_(3)N_(4).Additionally,a possible step-scheme photocatalytic reaction mechanism of Rh B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was tentatively proposed.PL and transient photocurrent analysis implied that Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts possessed the lower recombination rate of photogenerated carriers compared with pure Bi_(2) MoO_(6) and g-C_(3)N_(4),respectively.The present work is expected to provide useful information in designing 2D/2D S-scheme heterojunction photocatalysts.展开更多
Water is considered to be an inhibitor of CO oxidation.The mechanism of retarding the reaction is thought to contribute to the practical application of CO oxidation,which is investigated by constructing the coupling o...Water is considered to be an inhibitor of CO oxidation.The mechanism of retarding the reaction is thought to contribute to the practical application of CO oxidation,which is investigated by constructing the coupling of Au nanoparticles and defective CuO to form metal-support interactions(MSI)and oxygen vacancies(OVs).The introduction of Au forms a new CO adsorption site,which successfully solves the competitive adsorption problem of CO with H2O and O_(2).Due to the coupling of MSI and OVs,the reduced ability of catalyst and the activation and migration ability of oxygen are enhanced simultaneously.Au-CuO has the ability to oxidize CO at room temperature with high stability under a humid environment.Theoretical calculation confirmed the competitive adsorption and the influence of MSI and OVs coupling on the catalyst performance.The mechanism of water resistance in CO catalytic oxidation was also explained.展开更多
The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a nov...The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.展开更多
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JUSRP51716A)the National Natural Science Foundation of China(Nos.21203077 and 21773099)the financially support from the Qing Lan Project of Jiangsu Province。
文摘A novel 2D/2D Bi_(2)MoO_(6)/g-C_(3)N_(4) step-scheme(S-scheme)composite by loading Au as cocatalyst was successfully fabricated using a photoreduction and hydrothermal route.The obtained Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts were characterized by X-ray diffraction(XRD),transmission electron microscope(TEM),X-ray photo-electron spectroscopy(XPS),UV–vis diffuse reflectance spectra(UV–vis),Fourier transform infrared spectroscopy(FTIR),photoluminescence(PL),photocurrent response(I-t),and electrochemical impedance spectroscopy(EIS).The HRTEM images revealed that an intimate interface in composites were formed.The optimum photocatalytic activity of Rhodamine B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was about 9.7 times and 13.1 times as high as those of Bi_(2)MoO_(6) and g-C_(3)N_(4),respectively.The notably improved photocatalytic activity of Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au could be mainly ascribed to the abundant active sites and the enhanced separation efficiency of photogenerated carriers in Bi_(2)MoO_(6)/g-C_(3)N_(4) S-scheme system.Notably,Au nanoparticles could act as a co-catalyst to further promote electron transfer and separation from the conduction band of g-C_(3)N_(4).Additionally,a possible step-scheme photocatalytic reaction mechanism of Rh B degradation over Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au was tentatively proposed.PL and transient photocurrent analysis implied that Bi_(2)MoO_(6)/g-C_(3)N_(4)/Au photocatalysts possessed the lower recombination rate of photogenerated carriers compared with pure Bi_(2) MoO_(6) and g-C_(3)N_(4),respectively.The present work is expected to provide useful information in designing 2D/2D S-scheme heterojunction photocatalysts.
基金supported by the National Natural Science Foundation of China(Grant nos.51772183 and 52072230).
文摘Water is considered to be an inhibitor of CO oxidation.The mechanism of retarding the reaction is thought to contribute to the practical application of CO oxidation,which is investigated by constructing the coupling of Au nanoparticles and defective CuO to form metal-support interactions(MSI)and oxygen vacancies(OVs).The introduction of Au forms a new CO adsorption site,which successfully solves the competitive adsorption problem of CO with H2O and O_(2).Due to the coupling of MSI and OVs,the reduced ability of catalyst and the activation and migration ability of oxygen are enhanced simultaneously.Au-CuO has the ability to oxidize CO at room temperature with high stability under a humid environment.Theoretical calculation confirmed the competitive adsorption and the influence of MSI and OVs coupling on the catalyst performance.The mechanism of water resistance in CO catalytic oxidation was also explained.
文摘The search for visible-light-active,highly efficient and durable bi-functional photocatalysts is now essential for the development of various renewable energy sources and conversion technologies.Herein,we report a novel magnetically separable Au-loaded CaFe_(2)O_(4)/CoAl LDH heterostructure with strong coulombic interfacial interactions fabricated through a simple two-step process.XRD,XPS and TEM analysis of the synthesized samples were carried out for the structural and morphological characterization.The TEM study confirmed the existence of a firm attachment between the Au nanoparticles with the CaFe_(2)O_(4)/CoAl LDH heterostructures,which provides a unique support due to an exterior confinement effect.Formation of the heterojunction with a different electronic behaviour was also confirmed from an inverted V-shaped M-S plot,suggesting the presence of a large intimate contact interface between CoAl LDH and CaFe_(2)O_(4)to favour the efficient separation and transfer of photoinduced charge pairs.The CoAl LDH-CaFe_(2)O_(4)@Au ternary heterostructure showed a high hydrogen generation rate of 379.1μmol h^(−1),oxygen evolution rate of 205.5μmol h^(−1)and Cr(VI)reduction rate of 99%under visible light irradiation.The CoAl LDH-CaFe_(2)O_(4)@Au heterostructure demonstrated its long-term stability and durability during photocatalytic investigations.The efficient photocatalytic activity of the catalysts was due to the synergistic effect of hot electron transfer by Au nanoparticles and easy mass transport through the interface owing to formation of a p-n junction by increasing the contact area.The mechanism of the photocatalytic activity was also supported by PL,EIS and photocurrent measurements.This work provides a novel strategy to design junction-based nanostructures as a promising photocatalyst for solar energy conversion.
