The rational design and optimization of noble-metal-free semiconductor photocatalysts aim to increase the number of active sites and accelerate the separation and transfer of charges,thereby achieving high-performance...The rational design and optimization of noble-metal-free semiconductor photocatalysts aim to increase the number of active sites and accelerate the separation and transfer of charges,thereby achieving high-performance hydrogen evolution reactions(HER).In this study,we innovatively designed an S-scheme heterojunction catalyst composed of CdS nanoparticles rich in cationic Cd vacancies(VCCS)and ZnWO4nanorods rich in anionic O vacancies(VOZWO)that regulate the surface electronic states of the catalyst through dual vacancies engineering.Specifically,the introduction of vacancy engineering effectively adjusted the energy level structure of the catalyst,achieving bandgap narrowing,enhancing light absorption capacity,providing hole trapping sites,and creating more active sites.As expected,the optimized VOZWO@VCCS heterojunction exhibited exceptional photocatalytic H_(2)production rates of 11.55 mmol g^(-1)h^(-1)in the absence of noble-metal cocatalysts,which are approximately 462 times and4 times higher than those of pure VOZWO(0.025 mmol g^(-1)h^(-1))and VCCS(2.89 mmol g^(-1)h^(-1)),respectively.In-depth characterization tests and density functional theory(DFT)calculations revealed that the introduction of vacancies significantly reduced the bandgap,improved the transfer efficiency of photoinduced carriers,and validated the charge transfer mechanism of the S-scheme heterojunction.展开更多
基金supported by the National Natural Science Foundation of China(22271106,52073286)the Natural Science Foundation of Fujian Province(2006 L2005)。
文摘The rational design and optimization of noble-metal-free semiconductor photocatalysts aim to increase the number of active sites and accelerate the separation and transfer of charges,thereby achieving high-performance hydrogen evolution reactions(HER).In this study,we innovatively designed an S-scheme heterojunction catalyst composed of CdS nanoparticles rich in cationic Cd vacancies(VCCS)and ZnWO4nanorods rich in anionic O vacancies(VOZWO)that regulate the surface electronic states of the catalyst through dual vacancies engineering.Specifically,the introduction of vacancy engineering effectively adjusted the energy level structure of the catalyst,achieving bandgap narrowing,enhancing light absorption capacity,providing hole trapping sites,and creating more active sites.As expected,the optimized VOZWO@VCCS heterojunction exhibited exceptional photocatalytic H_(2)production rates of 11.55 mmol g^(-1)h^(-1)in the absence of noble-metal cocatalysts,which are approximately 462 times and4 times higher than those of pure VOZWO(0.025 mmol g^(-1)h^(-1))and VCCS(2.89 mmol g^(-1)h^(-1)),respectively.In-depth characterization tests and density functional theory(DFT)calculations revealed that the introduction of vacancies significantly reduced the bandgap,improved the transfer efficiency of photoinduced carriers,and validated the charge transfer mechanism of the S-scheme heterojunction.
