Design and in-situ construct BiOI/Bi/TiO_(2)photocatalysts with metal-mediated heterostructures employing oxygen vacancies in TiO_(2)nanosheets

查看全文 作　　者：Chenchen [1,2]Zhang;Wenbin [1]Chen;Dairong [1]Hu;Hanjie [2,3]Xie;Yibing [1]Song;Binbin [1]Luo;Yiwen [1]Fang;Wenhua [1]Gao;Ziyi [2,3]Zhong 机构地区：[1]Department of Chemistry,Shantou University,Guangdong,515063,China;[2]Department of Chemical Engineering,Guangdong Technion-Israel Institute of Technology(GTIIT),Guangdong,515063,China;[3]Technion-Israel Institute of Technology(IIT),Haifa,32000,Israel 出　　处：《Green Energy & Environment》索引2022年第7卷第4期,共11页 基　　金：financially supported by the National Natural Science Foundation of China(No.21043006 and 51702205);the Education Department of Guangdong Province(No.2018KTSCX063 and 2013KJCX0081);the Science and Technology Planning Project of Guangdong Province(No.2014A020216045);the 2020 Li Ka Shing Foundation Cross-Disciplinary Research Grant(2020LKSFG09A);the Guangdong Key Discipline Fund at GTIIT。 摘　　要：The conventional p-n heterojunction photocatalysts suffer from the incompatibility between the interfacial charge transfer efficiency and the redox ability of charge carriers.To optimize the interfacial charge transfer of the conventional BiOI/TiO_(2) p-n photocatalyst,we synthesized the BiOI/Bi/TiO_(2) ternary photocatalyst with sandwiched metallic bismuth(Bi~0)by the oxygen-vacancy assisted method.The DFT calculation and structural characterizations confirmed the reaction of the electron-rich oxygen vacancies in the 2D-TiO_(2) nanosheets(TiO_(2)-NS)with the adsorbed BiO~+species.This reaction broke the Bi-O bonds to form Bi^(0) nanoparticles in-situ at the interface but still maintained the p-n heterojunction well.The NO-TPD and XRD analyses for samples correlated the Bi~0 formation with the oxygen vacancy concentrations well.The sandwiched Bi~0 functioned as an electronic transfer mediator like that in the Z-scheme heterostructure.Comparing with 0.20 BiOI/TiO_(2)-NP(NP,Nanoparticles),0.20 BiOI/Bi/TiO_(2)-NS-a(NS,Nanosheet)showed a much improved catalytic performance,i.e.,duplicated apparent quantum yield(AQY)and triplicated reaction rate constant(k).Also,the formation mechanism and the reaction mechanism were investigated in detail.This work provides a new strategy for the improving of the conventional p-n photocatalysts and new insights into the nature of the photocatalysis. 关 键 词：TiO_(2)nanosheets Oxygen vacancy Metallic bismuth Sandwiched heterostructure Photocatalysis