FeS2-doped MoS2 nanoflower with the dominant 1T-MoS2 phase for enhanced peroxidase activity

Abstract

Nanozymes with peroxidase activity have lower catalytic activity compared to natural enzymes. Therefore, it is of great significance to develop and design artificial enzymes with high catalytic activity. FeS₂-doped MoS₂ (FeS₂-MoS₂) nanoflower is synthesized via a hydrothermal method, using Anderson-type polyoxometalates (FeMo₆) as precursors. The X-ray photoelectron spectroscopy (XPS) and Raman spectrum of FeS₂-MoS₂ confirm the presence of the 1T-MoS₂ phase. FeS₂-MoS₂ with different 1T/2H-MoS₂ phase ratios are synthesized by controlling the reaction time. As a nanozyme, the obtained FeS₂-MoS₂ can promote the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to oxTMB, showing peroxidase activity. FeS₂-MoS₂ at a reaction time of 12 h exhibits higher peroxidase activity compared to samples prepared at other reaction times. The catalytic activity of FeS₂-MoS₂ is 3 times that of MoS₂. The K_m value for H₂O₂ was 110 times that of horseradish peroxidase (HRP), indicating that the FeS₂-MoS₂ had a better affinity for H₂O₂. The excellent catalytic activity may be due to the synergistic effect of bimetal, larger specific surface area, the high content of 1T-MoS₂ (77.52 %) and defect. As far as we know, the FeS₂-MoS₂ nanoflower exhibits an exceptionally low detection limit of 0.52 μM for the colorimetric sensing of H₂O₂. This research presents a novel approach for creating high-performing nanozyme catalysts.