Phosphate-modified m-Bi2O4 enhances the absorption and photocatalytic activities of sulfonamide: Mechanism, reactive species, and reactive sites

Ping Chen; Qianxin Zhang; Xiaoshan Zheng; Cuiwen Tan; Meihui Zhuo; Tiansheng Chen; Fengliang Wang; Haijin Liu; Yang Liu; Yiping Feng; Wenying Lv; Guoguang Liu

doi:10.1016/j.jhazmat.2019.121443

Phosphate-modified m-Bi₂O₄ enhances the absorption and photocatalytic activities of sulfonamide: Mechanism, reactive species, and reactive sites

J Hazard Mater. 2020 Feb 15:384:121443. doi: 10.1016/j.jhazmat.2019.121443. Epub 2019 Oct 13.

Authors

Affiliations

¹ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
² Key Laboratory for Yellow River and Huaihe River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, 453007, China.
³ Faculty of Environmental and Biological Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, China.
⁴ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China. Electronic address: lvwy612@163.com.
⁵ School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China. Electronic address: liugg615@163.com.

PMID: 31630862
DOI: 10.1016/j.jhazmat.2019.121443

Abstract

Widespread usage of the sulfonamide class of antibiotics is causing increasing ecotoxicological concern, as they have the capacity to alter ambient ecosystems. Photocatalytic technology is an attractive yet challenging strategy for the degradation of antibiotics. For this work, the phosphate modification of m-Bi₂O₄ (Bi₂O₄-P) was prepared via a one-step hydrothermal process involving sodium bismuthate and sodium phosphate, which was employed for the degradation of sulfamethazine (SMZ) under visible light irradiation. The 0.5% Bi₂O₄-P exhibited excellent photocatalytic performance, which was 1.9 times that of pure m-Bi₂O₄. The photocatalytic degradation kinetics and mechanism of SMZ was investigated at different pH, whereupon it was revealed that m-Bi₂O₄-P exhibited improved SMZ adsorption and photocatalytic activities in contrast to pure m-Bi₂O₄. Compared with other four sulfonamide antibiotics, structures that contained additional methyl on the pyrimidine could be more easily attacked by phosphate modified m-Bi₂O₄. Reactive species (RS) scavenging experiments revealed that h⁺ was primarily responsible for the degradation of SMZ. Further studies of RS by ESR technology, and the results of photoelectrochemical properties showed phosphate-modified m-Bi₂O₄ could make greater use of photogenerated carriers, thereby producing additional RS. Based on the HRAM LC-MS/MS and the Frontier Molecular Orbital Theory, the degradation pathways of SMZ were proposed.

Keywords: Degradation pathways; Phosphate modification; Reactive species; Sulfamethazine; m-Bi(2)O(4).

Publication types

Research Support, Non-U.S. Gov't