Revealing the Intrinsic Peroxidase-Like Catalytic Mechanism of O–doped CoS2 Nanoparticles

CoS2 nanoparticles (NPs) have shown promise as potential peroxidase (POD)-like catalysts, but the catalytic molecular mechanisms are largely unknown. Moreover, no study has adequately explored the influence of O-doping induced by the inevitable oxidation of CoS2 on their POD-like activity. Here, O-doped CoS2 NPs were prepared by a one-step method, and their intrinsic POD-like catalytic mechanism was investigated with a combined experimental and theoretical approach. The hydroxyl radical (˙OH) and the superoxide radical (O2˙-) have been found to play significant roles in the POD-like activity, and ˙OH is the major radical. The O-doping could reduce the transition-state energy barrier of H2O2 dissociation, thus promoting the decomposition of H2O2 to ˙OH and inducing the formation of O2˙-. Therefore, O-doping is an effective method for enhancing the catalytic activity of CoS2 NPs. Furthermore, due to the excellent oxidation property of ˙OH and O2˙-, this nanozyme exhibited efficient catalytic activity towards the degradation of organic dyes with H2O2. This manuscript provides a new inspiration for designing more promising anion-defective transition-metal sulfide nanozymes for different applications.