CdS quantum dots sensitized platelike WO_3 photoelectrodes were successfully synthesized by a facile hydrothermal method and a modified chemical bath deposition(CBD) technique.To further improve the stability of the p...CdS quantum dots sensitized platelike WO_3 photoelectrodes were successfully synthesized by a facile hydrothermal method and a modified chemical bath deposition(CBD) technique.To further improve the stability of the photoelectrodes in alkaline environment,the platelike WO_3 films were treated with TiCl_4 to form a nano-TiO_2 buffer layer on the WO_3 plate surface before loading CdSQDs.The resulting electrodes were characterized by using XRD,SEM,HR-TEM and UV-vis spectrum.The photocatalytic activity of the resulting electrodes was investigated by degradation of methyl orange(MO) in aqueous solution.The photoelectrochemical(PEC) property of the resulting electrodes was also characterized by the linear sweep voltammetry.The results of both the degradation of MO and photocurrent tests indicated that the as-prepared CdSQDs sensitized WO_3 platelike photoelectrodes exhibit a significant improvement in photocatalytic degradation and PEC activity under visible light irradiation,compared with unsupported CdSQDs electrodes.Significantly,coating the WO_3 plates with nano-TiO_2 obviously facilitate the charge separation and retards the charge-pair recombination,and results in a highest activity for QDsCdS/TiO_2/WO_3 photoelectrodes.展开更多
Exploring the intricate relationship between noble metal ensembles and supporting materials stands as a captivating frontier in chemistry and catalysis.However,the precise control of noble metal ensembles on inert sup...Exploring the intricate relationship between noble metal ensembles and supporting materials stands as a captivating frontier in chemistry and catalysis.However,the precise control of noble metal ensembles on inert support remains challenging.We present here a facile strategy to construct noble metal ensembles,ranging from single atom to clusters or nanoparticles,on inert pure-silica zeolites.Typically,the internal silanol nests of silicalite-1(S-1)platelike zeolites are identified as anchoring sites for Pt ensembles.The dynamic interplay between silanol nests and Pt precursors in solution phase are monitored to reveal the formation and evolution of Pt ensembles.Various Pt ensembles on S-1 zeolites show distinct catalytic behaviors in the model reaction of benzonitrile hydro-conversion.Thereinto,Pt1/S-1 catalyst containing exclusive mononuclear ionic Ptδ+sites shows remarkable performance in the hydro-conversion of benzonitrile to di-benzylamine,which can be extended to the synthesis of secondary amines from the hydro-conversion of nitriles or nitriles/amines mixtures.The methodology developed herein offers the precise control of noble metal ensembles on inert zeolite support towards selective catalysis.展开更多
基金Project(2014FJ3041)supported by the Research Funds of Science and Technology Agency of Hunan Provincial,ChinaProject(14A076)supported by the Research Funds of Education Agency of Hunan Provincial,ChinaProject supported by the Postdoctoral Science Foundation of Central South University,China
文摘CdS quantum dots sensitized platelike WO_3 photoelectrodes were successfully synthesized by a facile hydrothermal method and a modified chemical bath deposition(CBD) technique.To further improve the stability of the photoelectrodes in alkaline environment,the platelike WO_3 films were treated with TiCl_4 to form a nano-TiO_2 buffer layer on the WO_3 plate surface before loading CdSQDs.The resulting electrodes were characterized by using XRD,SEM,HR-TEM and UV-vis spectrum.The photocatalytic activity of the resulting electrodes was investigated by degradation of methyl orange(MO) in aqueous solution.The photoelectrochemical(PEC) property of the resulting electrodes was also characterized by the linear sweep voltammetry.The results of both the degradation of MO and photocurrent tests indicated that the as-prepared CdSQDs sensitized WO_3 platelike photoelectrodes exhibit a significant improvement in photocatalytic degradation and PEC activity under visible light irradiation,compared with unsupported CdSQDs electrodes.Significantly,coating the WO_3 plates with nano-TiO_2 obviously facilitate the charge separation and retards the charge-pair recombination,and results in a highest activity for QDsCdS/TiO_2/WO_3 photoelectrodes.
基金supported by the National Natural Science Fund of China(grant nos.22025203 and 22302099)China Postdoctoral Science Fund(grant nos.2023M731797 and 2024T170438)the Fundamental Research Funds for the Central Universities(Nankai University).
文摘Exploring the intricate relationship between noble metal ensembles and supporting materials stands as a captivating frontier in chemistry and catalysis.However,the precise control of noble metal ensembles on inert support remains challenging.We present here a facile strategy to construct noble metal ensembles,ranging from single atom to clusters or nanoparticles,on inert pure-silica zeolites.Typically,the internal silanol nests of silicalite-1(S-1)platelike zeolites are identified as anchoring sites for Pt ensembles.The dynamic interplay between silanol nests and Pt precursors in solution phase are monitored to reveal the formation and evolution of Pt ensembles.Various Pt ensembles on S-1 zeolites show distinct catalytic behaviors in the model reaction of benzonitrile hydro-conversion.Thereinto,Pt1/S-1 catalyst containing exclusive mononuclear ionic Ptδ+sites shows remarkable performance in the hydro-conversion of benzonitrile to di-benzylamine,which can be extended to the synthesis of secondary amines from the hydro-conversion of nitriles or nitriles/amines mixtures.The methodology developed herein offers the precise control of noble metal ensembles on inert zeolite support towards selective catalysis.
