title: Synergistic photocatalysis of Cr(VI) reduction and 4-Chlorophenol degradation over hydroxylated α-Fe2O3 under visible light irradiation.
abstract: A series of Fe2O3 materials with hydroxyl are synthesized in different monohydric alcohol (C2-C5) solvents by solvothermal method and characterized by XRD, BET, XPS, TG and EA. The amount of hydroxyl is demonstrated to be emerged on the surface of the as-synthesized Fe2O3 particles and their contents are determined to be from 7.99 to 3.74 wt%. The Cr(VI) reduction experiments show that the hydroxyl content of Fe2O3 samples exacts great influence on the photocatalytic activity under visible light irradiation (λ>400 nm) and that the Fe2O3 sample synthesized in n-butyl alcohol exhibits the optimal photocatalytic activity. The synergistic photocatalysis for 4-Chlorophenol (4-CP) degradation and Cr(VI) reduction over above Fe2O3 sample is further investigated. The photocatalytic ratio of Cr(VI) reduction are enhanced from 24.8% to 70.2% while that of 4-CP oxidation are increased from 13.5% to 47.8% after 1 h visible light irradiation. The Fe2O3 sample keeps good degradation rates of mixed pollutants after 9 runs. The active oxygen intermediates O2(-)˙, ˙OH and H2O2 formed in the photoreaction process are discovered by ESR measurement and UV-vis test. The photocatalytic degradation mechanism is proposed accordingly.
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China.
authors.forename: Ji-Chao
authors.initials: JC
authors.lastname: Wang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Ren
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China. Electronic address: yaohongchang@zzu.edu.cn.
authors.forename: Hong-Chang
authors.initials: HC
authors.lastname: Yao
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China.
authors.forename: Jian-She
authors.initials: JS
authors.lastname: Wang
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China.
authors.forename: Shuang-Quan
authors.initials: SQ
authors.lastname: Zang
authors.affiliation: Henan Provincial Key Laboratory of Surface & Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
authors.forename: Li-Feng
authors.initials: LF
authors.lastname: Han
authors.affiliation: College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450002, China. Electronic address: lizhongjun@zzu.edu.cn.
authors.forename: Zhong-Jun
authors.initials: ZJ
authors.lastname: Li
keywords: 4-Chlorophenol oxidation; Cr(VI) reduction; Fe(2)O(3); Surface hydroxyl; Synergistic effect