Mechanistic insights and DFT analysis of bimetal doped styrofoam-like LaFeO3 perovskites with in-built dual redox couples for enhanced Photo-Fenton degradation of Tetracycline

Abstract

The rising number of contaminants released into the environment and the inadequacies of traditional wastewater treatment techniques have led to the demand for enhanced oxidation technologies like photo-Fenton. In this study, bimetal co-doped lanthanum orthoferrite (Bi<inf>x</inf>La<inf>1-x</inf>Cu<inf>y</inf>Fe<inf>1-y</inf>O<inf>3</inf> (x = 0, 0.01, 0.05, 0.1; y = 0, 0.01, 0.05, 0.1, 0.15)) based photo-Fenton catalysts with the in-built redox couples Fe3+/Fe2+, Cu2+/Cu+ and oxygen vacancies have been successfully synthesised via a facile one-pot solution combustion route. Systematic studies show that the Bi<inf>0.05</inf>La<inf>0.95</inf>Cu<inf>0.1</inf>Fe<inf>0.9</inf>O<inf>3</inf> (LFOBC) exhibits an optimal photo-Fenton degradation rate of 0.0497/min for Tetracycline (TC) removal, being ∼ 1.8 and ∼ 6.2 times greater than Bi<inf>0.05</inf>La<inf>0.95</inf>FeO<inf>3</inf> (LFOB) and pristine LaFeO<inf>3</inf> (LFO) respectively. DFT analysis confirmed the better adsorption and dissociation of H<inf>2</inf>O<inf>2</inf> on a bimetal co-doped catalyst and identified the electron density difference in LFOBC, which can induce the H<inf>2</inf>O<inf>2</inf> dissociation. A detailed investigation of various influencing reaction parameters is explored. The degradation pathway for the LFOBC catalyst with the toxicological characteristics of each intermediate is analysed. This study presents the Bi<inf>0.05</inf>La<inf>0.95</inf>Cu<inf>0.1</inf>Fe<inf>0.9</inf>O<inf>3</inf> as a potential photocatalyst for enhanced photo-Fenton degradation with excellent efficiency observed for the degradation of various harmful pollutants for environmental remediation. © 2024 Elsevier B.V.