The electronic structures of various Cu^(+) luminescence centers in wurtzite ZnS are studied by using first-principles linear muffin-tin-orbital method combining atomic sphere approximation.The results for ZnS:Cu:Cl a...The electronic structures of various Cu^(+) luminescence centers in wurtzite ZnS are studied by using first-principles linear muffin-tin-orbital method combining atomic sphere approximation.The results for ZnS:Cu:Cl and ZnS:Cu:Al show that Cu acceptor states are anomalously deep(beyond 2.7eV above the top of valence band)and located near the bottom of conduction band in these two cases.On the other hand,the results for ZnS:Cu with sulfur vacancies manifest that the Cu+center is an associated center,whose Cu d-like states are situated above the top of valence band.展开更多
Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme hetero...Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.展开更多
文摘The electronic structures of various Cu^(+) luminescence centers in wurtzite ZnS are studied by using first-principles linear muffin-tin-orbital method combining atomic sphere approximation.The results for ZnS:Cu:Cl and ZnS:Cu:Al show that Cu acceptor states are anomalously deep(beyond 2.7eV above the top of valence band)and located near the bottom of conduction band in these two cases.On the other hand,the results for ZnS:Cu with sulfur vacancies manifest that the Cu+center is an associated center,whose Cu d-like states are situated above the top of valence band.
文摘Designing a step-scheme(S-scheme)heterojunction photocatalyst with vacancy engineering is a reliable approach to achieve highly efficient photocatalytic H_(2)production activity.Herein,a hollow ZnO/ZnS S-scheme heterojunction with O and Zn vacancies(VO,Zn-ZnO/ZnS)is rationally constructed via ion-exchange and calcination treatments.In such a photocatalytic system,the hollow structure combined with the introduction of dual vacancies endows the adequate light absorption.Moreover,the O and Zn vacancies serve as the trapping sites for photo-induced electrons and holes,respectively,which are beneficial for promoting the photo-induced carrier separation.Meanwhile,the S-scheme charge transfer mechanism can not only improve the separation and transfer efficiencies of photo-induced carrier but also retain the strong redox capacity.As expected,the optimized VO,Zn-ZnO/ZnS heterojunction exhibits a superior photocatalytic H_(2) production rate of 160.91 mmol g^(-1)h^(-1),approximately 643.6 times and 214.5 times with respect to that obtained on pure ZnO and ZnS,respectively.Simultaneously,the experimental results and density functional theory calculations disclose that the photo-induced carrier transfer pathway follows the S-scheme heterojunction mechanism and the introduction of O and Zn vacancies reduces the surface reaction barrier.This work provides an innovative strategy of vacancy engineering in S-scheme heterojunction for solar-to-fuel energy conversion.
