title: Temperature-induced phase changes in bismuth oxides and efficient photodegradation of phenol and p-chlorophenol.
abstract: A novel, simple and efficient approach for photodegrading phenol and p-chlorophenol, based on BixOy, was reported for the first time. Monoclinic Bi2O4 was prepared by the hydrothermal treatment of NaBiO3·2H2O. A series of interesting phase transitions happened and various bismuth oxides (Bi4O7, β-Bi2O3 and α-Bi2O3) were obtained by sintering Bi2O4 at different temperatures. The results demonstrated that the Bi2O4 and Bi4O7 phase had strong abilities towards the oxidative decomposition of phenol and p-chlorophenol and very high rates of TOC removal were observed. The characterization by XRD and XPS revealed that Bi(4+) in Bi2O4 and Bi(3.5+) in Bi4O7 were reduced to Bi(3+) during the reaction process. Singlet oxygen ((1)O2) was identified as the major reactive species generated by Bi2O4 and Bi4O7 for the photodegradation of p-chlorophenol and phenol. This novel approach could be used as a highly efficient and green technology for treating wastewaters contaminated by high concentrations of phenol and chlorophenols.
authors.affiliation: Research Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang, Jiangxi 330096, PR China; Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002, PR China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002, PR China. Electronic address: dzli@fzu.edu.cn.
authors.forename: Danzhen
authors.initials: D
authors.lastname: Li
authors.affiliation: Research Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang, Jiangxi 330096, PR China.
authors.forename: Fuqian
authors.initials: F
authors.lastname: Sun
authors.affiliation: Research Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang, Jiangxi 330096, PR China.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Weng
authors.affiliation: Research Institute of Applied Chemistry, Jiangxi Academy of Sciences, Nanchang, Jiangxi 330096, PR China.
authors.forename: Shengyong
authors.initials: S
authors.lastname: You
authors.affiliation: Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shao
keywords: Bismuth oxide; Mixed valence; Phenol; Photodegradation; p-Chlorophenol