Efficient photo-Fenton degradation of water pollutants via peracetic acid activation over sulfur vacancies-rich metal sulfides/MXenes

Photo-Fenton processes promise removal of various recalcitrant organic pollutants from water in a low-carbon manner, but the low reactivity and inadequate stability of the existing photocatalytic systems remain key barriers to their practical application. Here, we constructed a heterojunction catalyst, consisting of titanium carbide (Ti₃C₂ MXene) and cobalt-doped zinc sulfide (ZnS), for efficient photocatalytic activation of peracetic acid (PAA) and pollutants degradation. The system exhibited 10 times faster kinetics for tetracycline hydrochloride (TCH) degradation than that of the ZnCoS/PAA group, and far outperformed most of the existing photocatalytic systems. The abundantly-formed sulfur vacancy (SVs), induced by the Ti₃C₂ introduction into ZnCoS, played a key role in the activity augmentation through simultaneously promoting the process of light adsorption, photocharge separation, and PAA activation. The nonradical-dominated pathway also endowed the system superior environmental robustness and stability. Its feasibility for treating real river water and tap water under sunlight was also demonstrated, implying a great potential for practical water treatment. Our work may inspire new development of photocatalytic decontamination technologies towards sustainable environmental remediation applications and beyond.