Enhanced activation of peroxymonosulfate on layered molybdenum disulfide loaded with Co–La bimetallic oxide for efficient degradation of chloramphenicol

The use of transition metal-activated peroxymonosulfate (PMS) as an advanced oxidation technology has gained recognition. This study developed a catalyst using cobalt–lanthanum bimetallic oxide supported on layered molybdenum disulfide (MoS₂) as a carrier. The Co–La/MoS₂ catalyst was synthesised through coprecipitation, followed by calcination with an optimised metal ratio of Co:La = 2:1 to activate PMS and degrade trace chloramphenicol (CAP) in water. The chemical composition of the catalyst was confirmed using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). At catalyst and PMS dosages of 0.1 and 0.5 g·L⁻¹, respectively, the degradation rate of CAP was 95% within 30 min. The catalyst exhibited strong resistance to most interfering anions and maintained a high degradation rate at pH 3–11. Liquid chromatography–mass spectrometry analysis revealed the potential degradation pathways of CAP in the Co–La/MoS₂ (2:1)/PMS system. For other pollutants, such as oxytetracycline, complete degradation was achieved within 20 min, demonstrating the broad applicability of the Co–La/MoS₂ (2:1)/PMS system for the degradation and removal of antibiotic organic contaminants. This study offers a feasible approach for the degradation of antibiotic organic pollutants, including CAP, in natural water bodies.