Interface engineering-induced perovskite/spinel LaCoO3/Co3O4 heterostructured nanocomposites for efficient peroxymonosulfate activation to degrade levofloxacin

Cheng Cheng; Lian Chang; Xiaodan Zhang; Qingchen Deng; Hongxiang Chai; Yuming Huang

doi:10.1016/j.envres.2023.115994

Interface engineering-induced perovskite/spinel LaCoO₃/Co₃O₄ heterostructured nanocomposites for efficient peroxymonosulfate activation to degrade levofloxacin

Environ Res. 2023 Jul 15:229:115994. doi: 10.1016/j.envres.2023.115994. Epub 2023 Apr 25.

Authors

Cheng Cheng¹, Lian Chang¹, Xiaodan Zhang², Qingchen Deng¹, Hongxiang Chai³, Yuming Huang⁴

Affiliations

¹ Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
² Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
³ Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing, 400045, China. Electronic address: chaihx@cqu.edu.cn.
⁴ Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China. Electronic address: ymhuang@swu.edu.cn.

PMID: 37105283
DOI: 10.1016/j.envres.2023.115994

Abstract

Conventional perovskite oxides (ABO₃) tend to suffer from their inactive surfaces and limited active sites that reduce their catalytic activity and stability, while interface engineering is a facile modulating technique to boost the catalyst's inherent activity by constructing heterogeneous interfaces. In this study, perovskite/spinel LaCoO₃/Co₃O₄ nanocomposites with heterogeneous interfaces were synthesized via sol-gel and in-situ gradient etching methods to activate peroxymonosulfate (PMS) for degrading levofloxacin (LEV). LaCoO₃ on the surface was etched into spinel Co₃O₄, and LaCoO₃/Co₃O₄ nanocomposites with two crystal structures of perovskite and spinel were successfully formed. The surface-modified LaCoO₃/Co₃O₄ exhibited superior catalytic performance with a reaction rate constant more than 2 times that of the original LaCoO₃, as well as excellent pH adaptability (3-11) and reusability (more than 6 recyclings) for LEV degradation. Besides, multiple characterization techniques were carried out to find that LaCoO₃/Co₃O₄ possessed a larger specific surface area and richer oxygen vacancies after surface modification, which provided more active sites and accelerated mass transfer rate. The mechanism of reactive oxygen species involved in the reaction system was proposed that LaCoO₃/Co₃O₄ not only reacted with PMS directly to produce SO₄^•- and ^•OH but also its surface hydroxyl group helped to form the [≡Co(Ⅲ)OOSO₃]⁺ reactive complex with PMS to produce O₂^•- and ¹O₂. In addition, electrochemical experiments demonstrated that the surface electronic structure of LaCoO₃/Co₃O₄ was effectively regulated, exhibiting a faster electron transfer rate and facilitating the redox process. By detecting and identifying degradation intermediates, three degradation pathways for LEV were proposed. Our work provided profound insights into the design of efficient and long-lasting catalysts for advanced oxidation processes.

Keywords: Advanced oxidation processes; Interface engineering; Levofloxacin; Perovskite/spinel; Peroxymonosulfate; Surface modification.

Publication types

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

MeSH terms

Levofloxacin*
Nanocomposites*
Oxides
Oxygen

Substances

cobalt tetraoxide
perovskite
peroxymonosulfate
spinell
Levofloxacin
Oxides
Oxygen