Engineering oxygen vacancies rich nano-heterojunction for enhanced visible-light-driven photo-Fenton degradation of sulfamethoxazole

Oxygen vacancy-rich FeCo 2 O 4 @SnO 2 (FCO@SnO 2 ) hexagonal nanorods were synthesized via an aging-mediated calcination process. The photocatalyst demonstrated exceptional photo-Fenton degradation efficiency, achieving 98.3 % sulfamethoxazole (SMX) degradation under visible light irradiation. The enhanced activity can be attributed to the efficient charge separation and transfer, and the dominant (111) facet exposure in FeCo 2 O 4 could amplifies the generation of reactive oxygen species (ROS). Additionally, the oxygen vacancy in FeCo 2 O 4 effectively traps electrons , minimizing recombination and further enhancing photocatalytic efficiency. The photocatalyst exhibits a high surface area of 155.18 m 2 /g and pore radius of 1.696 nm, facilitating superior reactant adsorption and accelerated degradation with a kinetics rate constant of 0.0544 min −1 . Spin-orbit coupling in the FCO@SnO 2 hybrid boosts OH radical production, creating a highly oxidative environment. Importantly, the hybrid showed outstanding stability, maintaining 97.6 % degradation efficiency after six consecutive cycles, highlighting its suitability for long-term applications. To ensure environmental safety, the toxicity of intermediate metabolites formed during SMX degradation was analysed by using ECOSAR program, confirming their non-toxic nature. The present study demonstrates the FCO@SnO 2 nanohybrid as a high-performance catalyst with superior degradation efficiency, stability, and environmentally benign properties. The findings underscore its potential as a transformative solution for advanced wastewater treatment technologies, addressing critical challenges in environmental remediation. • FeCo 2 O 4 @SnO 2 hexagonal nanorod showed the SMX degradation of 98.6 %. • Oxygen vacancies in the photocatalyst ensure enhanced charge separation. • The material exhibited excellent stability and reusability. • OH radical played the major role is photodegradation. • Toxicity assessment of intermediates formed were determined by ECOSAR tool.