Three-Dimensional BiOI/BiOX (X = Cl or Br) Nanohybrids for Enhanced Visible-Light Photocatalytic Activity.
Three-dimensional flower-like BiOI/BiOX (X = Br or Cl) hybrids were synthesized via a facile one-pot solvothermal approach. With systematic characterizations by X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), the Brunauer-Emmett-Teller (BET)specific surface area, X-ray photoelectron spectroscopy (XPS), and the UV-Vis diffuse reflectance spectra (DRS), the BiOI/BiOCl composites showed a fluffy and porous 3-D architecture with a large specific surface area (SSA) and high capability for light absorption. Among all the BiOX (X = Cl, Br, I) and BiOI/BiOX (X = Cl or Br) composites, BiOI/BiOCl stands out as the most efficient photocatalyst under both visible and UV light irradiations for methyl orange (MO) oxidation. The reaction rate of MO degradation on BiOI/BiOCl was 2.1 times higher than that on pure BiOI under visible light. Moreover, BiOI/BiOCl exhibited enhanced water oxidation efficiency for O₂ evolution which was 1.5 times higher than BiOI. The enhancement of photocatalytic activity could be attributed to the formation of a heterojunction between BiOI and BiOCl, with a nanoporous structure, a larger SSA, and a stronger light absorbance capacity especially in the visible-light region. The in situ electron paramagnetic resonance (EPR) revealed that BiOI/BiOCl composites could effectively evolve superoxide radicals and hydroxyl radicals for photodegradation, and the superoxide radicals are the dominant reactive species. The superb photocatalytic activity of BiOI/BiOCl could be utilized for the degradation of various industrial dyes under natural sunlight irradiation which is of high significance for the remediation of industrial wastewater in the future.
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia. yazi.liu@postgrad.curtin.edu.au.|School of Chemistry and Life Science, Nanjing University Jinling College, Nanjing 210089, China. yazi.liu@postgrad.curtin.edu.au.
Yazi
Y
Liu
School of Chemistry and Life Science, Nanjing University Jinling College, Nanjing 210089, China. xj_tank@163.com.
Jian
J
Xu
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China. wangliqiong168@163.com.
Liqiong
L
Wang
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia. huayang.zhang@postgrad.curtin.edu.au.
Huayang
H
Zhang
School of Chemistry and Life Science, Nanjing University Jinling College, Nanjing 210089, China. xupzerone@gmail.com.
Ping
P
Xu
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia. xiaoguang.duan@curtin.edu.au.
Xiaoguang
X
Duan
School of Engineering, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027, Australia. h.sun@ecu.edu.au.
Hongqi
H
Sun
Department of Chemical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia. shaobin.wang@curtin.edu.au.
Shaobin
S
Wang
BiOI/BiOCl; degradation; heterojunction; photocatalysis; visible light; water oxidation