Copper in LaMnO3 to promote peroxymonosulfate activation by regulating the reactive oxygen species in sulfamethoxazole degradation

Panpan Gao; Xike Tian; Wei Fu; Yanxin Wang; Yulun Nie; Chao Yang; Yang Deng

doi:10.1016/j.jhazmat.2021.125163

Copper in LaMnO₃ to promote peroxymonosulfate activation by regulating the reactive oxygen species in sulfamethoxazole degradation

J Hazard Mater. 2021 Jun 5:411:125163. doi: 10.1016/j.jhazmat.2021.125163. Epub 2021 Jan 16.

Authors

Panpan Gao¹, Xike Tian², Wei Fu², Yanxin Wang¹, Yulun Nie³, Chao Yang², Yang Deng⁴

Affiliations

¹ School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China.
² Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, PR China.
³ Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, PR China. Electronic address: ylnie@cug.edu.cn.
⁴ Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.

PMID: 33485238
DOI: 10.1016/j.jhazmat.2021.125163

Abstract

Perovskites with flexible texture structures and excellent catalytic properties have attracted considerable attention in peroxymonosulfate (PMS) activation for addressing organic contaminants in water. In this study, the role of copper to promote PMS activation performance of LaMnO₃ was investigated. 100% sulfamethoxazole (SMX) degradation and 34% mineralization were achieved over copper doped LaMnO₃ while only 60% SMX was removed without TOC removal by LaMnO₃. Especially, compared with LaMnO₃, the pseudo-first-order reaction rate constant was increased by 8.30 times when the atomic ratio of Cu/Mn was 1:3. It proved that only ¹O₂ was generated in LaMnO₃ while ¹O₂, especially •OH and SO₄•^- were all detected in Cu-LaMnO₃/PMS system. The characterization results showed that Cu induced the formation of LaMnO₃ and La₂CuO₄ heterostructure with enhanced content of relatively low-valence Mn and Cu and abundant oxygen vacancies (OVs). Hence, the efficient PMS activation by Cu-LaMnO₃ was due to regulating the produced reactive oxygen species (ROS). A radical dominant instead of ¹O₂ involved PMS activation mechanism over LaMnO₃-La₂CuO₄ was proposed for efficient degradation of SMX. Finally, the possible degradation pathways of SMX were discussed based on HPLC-MS analysis. This study provided a new insight of improving the catalytic activity of perovskites in PMS activation in water treatment.

Keywords: Copper; Heterostructure perovskites; PMS activation; Regulative ROS; Sulfamethoxazole.

Publication types

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