Cobalt-doped LaFeO3 for photo-Fenton degradation of organic pollutants and visible-light-assisted water splitting

Abstract

The increasing demand for clean energy sources and the growing concerns about environmental pollution have led to a significant interest in developing efficient photocatalytic and photoelectrochemical systems. Here, we report the visible-light-induced photo-Fenton catalytic degradation of Methylene Blue (MB) dye over LaFeO<inf>3</inf> and LaCo<inf> x</inf>Fe<inf>1−x</inf>O<inf>3</inf> (x = 0.01, 0.05, 0.1) catalysts synthesized via the facile combustion method. The LaCo<inf>0.01</inf>Fe<inf>0.99</inf>O<inf>3</inf> has significantly enhanced the photo-Fenton catalytic efficiency of LaFeO<inf>3</inf> from 67.75 to 93.85% for MB dye removal after 180 min of light irradiation. The rate constants calculated via the pseudo-first-order kinetics mechanism are found to be 0.00532/min for LaFeO<inf>3</inf> and 0.01476/min for LaCo<inf>0.01</inf>Fe<inf>0.99</inf>O<inf>3</inf>, respectively. In addition, the most effective LaCo<inf>0.01</inf>Fe<inf>0.99</inf>O<inf>3</inf> catalyst has demonstrated remarkable degradation performance towards Tetracycline (TC) and Methyl Orange (MO) dye with an efficacy of 93.81% and 69.67%, respectively, indicating its versatility. Further, the pristine and doped LaFeO<inf>3</inf> were structurally optimized using DFT, and the computed band gaps were following the experimental data. Interestingly, the same catalyst can be employed as a light-induced electrocatalyst in addition to water treatment by taking advantage of its dual functionality. The LaCo<inf>0.01</inf>Fe<inf>0.99</inf>O<inf>3</inf> catalyst achieved a benchmark current density of 10 mA/cm2 for H<inf>2</inf> evolution at an overpotential of 297 mV vs. RHE which further improved to 190 mV vs. RHE under illumination. This work provides valuable insights on partial Co incorporation at the B-site of LaFeO<inf>3</inf> for the development of visible-light-induced photocatalytic and electrocatalytic systems, which is hoped to contribute to the advancement of sustainable energy production and environmental remediation. © 2024, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.