title: Solvothermal syntheses of Bi and Zn co-doped TiO2with enhanced electron-hole separation and efficient photodegradation of gaseous toluene under visible-light.
abstract: This study investigated the effects of Bi doped and Bi-Zn co-doped TiO2on photodegradation of gaseous toluene. The doped TiO2with various concentration of metal was prepared using the solvothermal route and characterized by SEM, XRD, Raman, BET, DRS, XPS, PL and EPR. Their photocatalytic activities under visible-light irradiation were drastically influenced by the dopant content. The results showed that moderate metal doping levels were obviously beneficial for the toluene degradation, while high doping levels suppressed the photocatalytic activity. The photocatalytic degradation of toluene over TiBi1.9%O2and TiBi1.9%Zn1%O2can reach to 51% and 93%, respectively, which are much higher than 25% of TiO2. Bi doping into TiO2lattice generates new intermediate energy level of Bi below the CB edge of TiO2. The electron excitation from the VB to Bi orbitals results in the decreased band gap, extended absorption of visible-light and thus enhances its photocatalytic efficiency. Zn doping not only further enhances the absorption in this visible-light region, but also Zn dopant exists as the form of ZnO crystallites located on the interfaces of TiO2agglomerates and acts as a mediator of interfacial charge transfer to suppress the electron-hole recombination. These synergistic effects are responsible for the enhanced photocatalytic performance.
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Song-Cai
authors.initials: SC
authors.lastname: Cai
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: hpjia@iue.ac.cn.
authors.forename: Hong-Peng
authors.initials: HP
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China. Electronic address: jing.chen@fjirsm.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
keywords: Bi-Zn co-doped TiO(2); Electron-hole recombination; Photocatalytic degradation; Toluene; Visible-light