Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology...Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology still suffers from limited contact interfaces.In this study,the chemical vapor deposition(CVD)technique was for the first time used to construct the CdS/MoS_(2)heterojunction photoanode with a unique core-shell nanoarchitecture,in which a continuous crystalline MoS_(2)nanosheet layer was grown directly on one-dimensional(1D)oriented CdS nanorods(NRs)in a plane-to-plane stacking fashion.The optimization of junction thickness with adjustable MoS_(2)loading from mono to a few layers was achieved by experimental parameters variation.Systematic characterizations show that the MoS_(2)shell plays a dual role as an optical absorption booster for more photo-exciton generation and a surface passivator of trap states.Meanwhile,the formed heterojunction helps regulate the unidirectional charge migration for a significantly suppressed electron-hole recombination process,which synergistically contributes to higher quantum yield and efficiency.As a result,the optimized CdS/MoS_(2)heterojunction photoanode with 3-layered MoS_(2)wrapping exhibits the highest photocurrent density and photoconversion efficiency,over a two-fold increase,compared to those of pristine CdS and the previously reported CdS/MoS_(2)hetero-junctions.Moreover,due to the rapid hole extraction from CdS and transferred surface oxidation sites,the present CdS/MoS_(2)heterostructure demonstrates better corrosion resistance and higher photostability.The present work is expected to provide a versatile platform for exploiting the CVD technique to develop other MoS_(2)-based heterojunction photoelectrodes with extensive PEC applications.展开更多
文摘Heterojunction fabrication is a promising strategy that can greatly boost the charge carrier separation and improve the solar-to-hydrogen conversion efficiency of photoelectrochemical(PEC)cells.However,such technology still suffers from limited contact interfaces.In this study,the chemical vapor deposition(CVD)technique was for the first time used to construct the CdS/MoS_(2)heterojunction photoanode with a unique core-shell nanoarchitecture,in which a continuous crystalline MoS_(2)nanosheet layer was grown directly on one-dimensional(1D)oriented CdS nanorods(NRs)in a plane-to-plane stacking fashion.The optimization of junction thickness with adjustable MoS_(2)loading from mono to a few layers was achieved by experimental parameters variation.Systematic characterizations show that the MoS_(2)shell plays a dual role as an optical absorption booster for more photo-exciton generation and a surface passivator of trap states.Meanwhile,the formed heterojunction helps regulate the unidirectional charge migration for a significantly suppressed electron-hole recombination process,which synergistically contributes to higher quantum yield and efficiency.As a result,the optimized CdS/MoS_(2)heterojunction photoanode with 3-layered MoS_(2)wrapping exhibits the highest photocurrent density and photoconversion efficiency,over a two-fold increase,compared to those of pristine CdS and the previously reported CdS/MoS_(2)hetero-junctions.Moreover,due to the rapid hole extraction from CdS and transferred surface oxidation sites,the present CdS/MoS_(2)heterostructure demonstrates better corrosion resistance and higher photostability.The present work is expected to provide a versatile platform for exploiting the CVD technique to develop other MoS_(2)-based heterojunction photoelectrodes with extensive PEC applications.
