Sulfur defect-engineered MoS2 nanosheets with enhanced peroxidase-like activity

MoS2 nanosheets (NSs) have been found to possess the peroxidase-like activity and widely used in colorimetric sensors. However, the catalytic active sites of MoS2 NSs are still unclear. Herein, MoS2 NSs with sulfur defects were prepared using the molten salt method at different heating temperature (800 °C–1100 °C) and following by ultrasonic exfoliation. With the increasing of heating temperature, the crystallinity of MoS2 NSs is improved, accompanying with the decrement of S/Mo atomic ratio. The increment of sulfur defects in MoS2 NSs remarkably enhances the peroxidase-like activity of MoS2 NSs. The catalytic inhibition by phosphate-containing molecules further verifies the catalytic active sites of MoS2 NSs are Mo atoms with sulfur defects. Finally, the peroxidase-like activity of sulfur defect-rich MoS2 NSs was applied for the colorimetric detection of H2O2 and the inhibitor. This work helps to understand the peroxidase-like catalytic mechanism of MoS2 NSs.