Exploring Dual-Defect-Mediated Mo–FeS2/Bi@BiOBr Heterojunction for Photocatalytic-Assisted Fenton Degradation of Cefixime Antibiotic

Abstract The photocatalytic-assisted Fenton mechanism has garnered considerable significance in cefixime (CFX) remediation. However, the fabrication of a photocatalyst with superior performance persists as a formidable challenge. Herein, a synergistic dual-modulation involving Mo doping and in situ Bi engineering is rationally designed in the S-Scheme heterojunction via a facile solvothermal route. The as-fabricated heterojunction exhibited elevated optoelectronic and photoelectrochemical properties, significantly boosting the photocatalytic performance. Consequently, these interactions synergistically contributed to the substantial production of •O2– and •OH radicals, which endowed the superior photocatalytic-assisted Fenton performance at alkaline pH. Remarkably, 87.0% of CFX was degraded with the assistance of H2O2 (5 mM) within 75 min under light irradiation, corresponding to a pseudo-first-order rate constant of 0.0208 min–1. Additionally, the remarkable reusability and robust performance of the photocatalyst corroborate the sustaining Fe(II)/Fe(III) redox cycle. Thus, the study provides insights into cefixime photodegradation by the S-scheme heterojunction and has implications for wastewater applications.