Synthesis of Bi2WO6/Na-bentonite composites for photocatalytic oxidation of arsenic(iii) under simulated sunlight

Quancheng Yang; Yunxiang Dai; Zijian Huang; Jing Zhang; Ming Zeng; Changsheng Shi

doi:10.1039/c9ra06181a

Synthesis of Bi₂WO₆/Na-bentonite composites for photocatalytic oxidation of arsenic(iii) under simulated sunlight

RSC Adv. 2019 Sep 19;9(51):29689-29698. doi: 10.1039/c9ra06181a. eCollection 2019 Sep 18.

Authors

Quancheng Yang^{1

2

3}, Yunxiang Dai^{1

2

4}, Zijian Huang^{1

2

4}, Jing Zhang^{2

4}, Ming Zeng¹, Changsheng Shi³

Affiliations

¹ School of Chemical and Environmental Engineering, China University of Mining and Technology Beijing 100083 P. R. China.
² Key Laboratory of Environmental Nano-Technology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences Beijing 100085 P. R. China jingzhang@rcees.ac.cn.
³ Department of Environmental Engineering, North China Institute of Science and Technology Beijing 101601 P. R. China northinstitute@yeah.net.
⁴ National Engineering Laboratory for VOCs Pollution Control Materials & Technology, University of Chinese Academy of Sciences Beijing 101408 P. R. China.

Abstract

Novel Bi₂WO₆/bentonite (denoted as BWO/BENT) composites were prepared via a typical hydrothermal process and employed for the photocatalytic oxidation of arsenic(iii) (As(iii)). The properties of the prepared samples were characterized through X-ray diffraction, transmission and scanning electron microscopy, UV-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. Effects of the BENT ratio on the As(iii) removal were explored under simulated sunlight, and the best photocatalytic effect was observed for the composite with BWO : BENT = 7 : 3 w/w. Compared with the pure BWO, the BWO/BENT composites exhibited an improved photocatalytic ability in the removal of As(iii), which was mainly ascribed to the enlarged specific surface area and the suppressed electron-hole recombination by the incorporated BENT. Furthermore, photo-generated holes (h⁺) and superoxide radicals ·O₂ ^- were confirmed to be the major contributors to the oxidation of As(iii), and an associated mechanism of photocatalytic oxidation of As(iii) over BWO/BENT composites was proposed.