Synergistic construction of defect-rich nanozymes via montmorillonite support loading and iron doping for enhanced peroxidase-like activity

Abstract

Nanozyme technology bridges enzymatic and nano-catalytic systems, with the goal of clarifying enzymatic mechanisms and improving nanomaterial catalysis. However, enhancing the exposure of catalytically active sites remains a significant challenge in fully realizing the enzyme-mimicking catalytic activity and oxidative stress applications of nanozymes. Herein, we employed a combined strategy of support loading and elemental doping to synthesize molybdenum disulfide nanozymes (FMM) with abundant exposed sulfur vacancies. Experimental results demonstrated that montmorillonite (MMT) loading significantly reduced the particle size of MoS₂, while iron doping effectively introduced sulfur vacancies. Specific activity analysis revealed that the peroxidase-like activity of MoS₂ was enhanced by 4.05 times through MMT loading and by 4.07 times through Fe doping, respectively. In addition, steady-state kinetic analysis revealed that the catalytic efficiency of MMT-loaded MoS₂ and Fe-doped MoS₂ increased by 13.70 times and 3.24 × 10⁴ times, respectively, compared to pristine MoS₂. Furthermore, experimental data combined with density functional theory (DFT) calculations elucidated the catalytic mechanism of the Fe-doped MoS₂. The synthesized FMM nanozymes exhibited excellent antibacterial performance due to their high POD activity.