Cobalt-doped MoS₂ catalysts for enhanced peroxymonosulfate activation: Efficient degradation of micropollutants via superoxide radical-dominated pathways

Antibiotic wastewater poses significant environmental risks due to the persistent micropollutants such as tetracycline (TC), which contribute to the development of antibiotic resistance. In this study, cobalt-doped molybdenum disulfide (Co-MoS₂) catalysts were synthesized via the hydrothermal method to enhance peroxymonosulfate (PMS) activation for efficient TC degradation. Comprehensive material characterizations (XRD, FT-IR, SEM, XPS) confirmed the successful incorporation of Co into the MoS₂ lattice, resulting in a mesoporous structure with an increased specific surface area, improved charge transfer efficiency, and greater exposure of active sites. Under optimal conditions, the 3.0%Co-MoS₂ catalyst achieved 81.5% TC degradation within 40 min, with a reaction rate constant 41 times higher than that observed with PMS alone. Key operational parameters-including catalyst dosage, PMS concentration, pH, temperature, and the presence of common anions-were systematically optimized, demonstrating the system's broad applicability for degrading various micropollutants. Radical trapping and EPR analyses identified •O₂⁻ as the dominant reactive species, while the Co²⁺/Co³⁺ and Mo⁴⁺/Mo⁶⁺ redox cycles were found to facilitate continuous PMS activation. Furthermore, four-cycle stability tests confirmed the catalyst's excellent reusability and potential for practical antibiotic wastewater treatment. This work validates transition metal-doped sulfides as efficient, stable catalysts for antibiotic micropollutant removal via PMS-based advanced oxidation processes.