Simultaneous and efficient photocatalytic reduction of Cr(VI) and oxidation of trace sulfamethoxazole under LED light by rGO@Cu2O/BiVO4p-n heterojunction composite

Zhiyan Huang; Xide Dai; Zhujian Huang; Tenglu Wang; Lihua Cui; Jiaer Ye; Pingxiao Wu

doi:10.1016/j.chemosphere.2019.01.087

Simultaneous and efficient photocatalytic reduction of Cr(VI) and oxidation of trace sulfamethoxazole under LED light by rGO@Cu₂O/BiVO₄p-n heterojunction composite

Chemosphere. 2019 Apr:221:824-833. doi: 10.1016/j.chemosphere.2019.01.087. Epub 2019 Jan 18.

Authors

Zhiyan Huang¹, Xide Dai², Zhujian Huang³, Tenglu Wang⁴, Lihua Cui⁴, Jiaer Ye⁴, Pingxiao Wu⁵

Affiliations

¹ Key Laboratory of Agro-environments in Tropics (Ministry of Agriculture), College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.
² Key Laboratory of Agro-environments in Tropics (Ministry of Agriculture), College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China; Zhongshan Puchuan Testing Technology Co., Ltd., Zhongshan, 528478, PR China.
³ Key Laboratory of Agro-environments in Tropics (Ministry of Agriculture), College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China. Electronic address: zjhuang@scau.edu.cn.
⁴ Key Laboratory of Agro-environments in Tropics (Ministry of Agriculture), College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, PR China.
⁵ Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.

PMID: 30684780
DOI: 10.1016/j.chemosphere.2019.01.087

Abstract

Antibiotics and heavy metals often coexist in polluted environment, and the harm of combined pollution is greater than that of single pollution. In this study, a series of graphene supported p-n heterojunction rGO@Cu₂O/BiVO₄ composites are synthesized with different Cu₂O doping for simultaneous detoxification of Cr(VI) and antibiotics. The obtained photocatalysts (rGO@Cu₂O/BiVO₄) with proper loading amount of Cu₂O shows the a high photocatalytic degradation activity for simultaneously efficient Cr(VI) reduction and sulfamethoxazole (SMZ) oxidation under LED light at neutral pH. The Cr(VI) was completely transformed to Cr(III) rather than simply Cr(VI) adsorbed on the surface of rGO@Cu₂O/BiVO₄. The photocatalytic activity of composites can be attributed to excellent electrical conductivity of rGO and the p-n heterojunction between Cu₂O and BiVO₄, which promotes the spatial separation of photogenerated charges at the heterojunction boundary and inhibits of the photogenerated h⁺ and e^- recombination. It's confirmed that h⁺, O₂^- and OH are the main reactive species for the photocatalytic SMZ oxidation, and the most important reactive species is h⁺. Finally, the tentative degradation pathways of SMZ are proposed based on the liquid chromatography-triple quadrupole mass spectrometry analysis. This work provides an effective approach for the treatment of water that contains SMZ and Cr(VI) under LED light.

Keywords: Cr(VI); Intermediates; Photocatalytic reduction; Sulfamethoxazole; p-n heterojunction.

MeSH terms

Bismuth / chemistry*
Catalysis
Chromium / chemistry*
Copper / chemistry*
Light*
Oxidation-Reduction
Photochemical Processes*
Sulfamethoxazole / chemistry*
Vanadates / chemistry*
Water Pollutants, Chemical / chemistry

Substances

Water Pollutants, Chemical
Chromium
bismuth vanadium tetraoxide
chromium hexavalent ion
Vanadates
Copper
Sulfamethoxazole
cuprous oxide
Bismuth