To suppress the inner charge recombination and inject vast electrons,CdTe nanocrystals are embedded into ultrathin ZnIn_(2)S_(4) nanosheets to construct ZnIn_(2)S_(4)/CdTe heterostructures,where the nanocrystals are g...To suppress the inner charge recombination and inject vast electrons,CdTe nanocrystals are embedded into ultrathin ZnIn_(2)S_(4) nanosheets to construct ZnIn_(2)S_(4)/CdTe heterostructures,where the nanocrystals are generated by a laser irradiation method.The optimal ZnIn_(2)S_(4)/CdTe heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the ZnIn_(2)S_(4)-based photocatalysts with-out noble metals.This enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur vacancies.The strong electron coupling effect,which is verified by density functional the-ory(DFT)calculations,impels the photo-generated electrons transfer from CdTe to ZnIn_(2)S_(4),boosting the charge separation.Meanwhile,the sulfur vacancies existing in ZnIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the H_(2) generation reaction.In addition,the ZnIn_(2)S_(4) base and the ZnIn_(2)S_(4)/CdTe heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic performance.This research provides new insights into the regulation of charge transfer through embedding nanocrystals.展开更多
Purpose A structure,used as a complex source of X-rays and neutron source,is designed with the assistance of CST module tool.Methods Particles of H-and electron,attracted from a plasma source,are designed to be separa...Purpose A structure,used as a complex source of X-rays and neutron source,is designed with the assistance of CST module tool.Methods Particles of H-and electron,attracted from a plasma source,are designed to be separated by an energy selector.Soon after the separation,the trajectory and beam quality of H-are controlled by a special designation of potential barrier and potential well.And both particles are then accelerated by three pairs of pierce similar pole to an energy of 150 keV to produce X-rays/neutron.Results With proper optimization of structure and potential combination,a binocular structure with beam center distance of 15 mm,beam diameter smaller than 3.5 mm has been devised,which gives a feasible suggestion to produce two rays with one structure in the same time.展开更多
基金The research was sponsored by the National Natural Science Foundation of China(Nos.52172101 and 51872240)the National Key R&D Program for International Cooperation(No.2021YFE0115100)+2 种基金Shaanxi Province Key Research and Develop-ment Program(No.2021ZDLGY14-08)the Fundamental Research Funds for the Central Universities(No.3102019JC005)the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110228).The authors thank the Analysis and Test Center of Northwestern Polytechnical University and Shaanxi Materials Analysis and Research Center for XPS,SEM,and TEM characterizations.
文摘To suppress the inner charge recombination and inject vast electrons,CdTe nanocrystals are embedded into ultrathin ZnIn_(2)S_(4) nanosheets to construct ZnIn_(2)S_(4)/CdTe heterostructures,where the nanocrystals are generated by a laser irradiation method.The optimal ZnIn_(2)S_(4)/CdTe heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the ZnIn_(2)S_(4)-based photocatalysts with-out noble metals.This enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur vacancies.The strong electron coupling effect,which is verified by density functional the-ory(DFT)calculations,impels the photo-generated electrons transfer from CdTe to ZnIn_(2)S_(4),boosting the charge separation.Meanwhile,the sulfur vacancies existing in ZnIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the H_(2) generation reaction.In addition,the ZnIn_(2)S_(4) base and the ZnIn_(2)S_(4)/CdTe heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic performance.This research provides new insights into the regulation of charge transfer through embedding nanocrystals.
文摘Purpose A structure,used as a complex source of X-rays and neutron source,is designed with the assistance of CST module tool.Methods Particles of H-and electron,attracted from a plasma source,are designed to be separated by an energy selector.Soon after the separation,the trajectory and beam quality of H-are controlled by a special designation of potential barrier and potential well.And both particles are then accelerated by three pairs of pierce similar pole to an energy of 150 keV to produce X-rays/neutron.Results With proper optimization of structure and potential combination,a binocular structure with beam center distance of 15 mm,beam diameter smaller than 3.5 mm has been devised,which gives a feasible suggestion to produce two rays with one structure in the same time.
