Insight into the Peroxidase-Like Catalytic Active Sites of Mos2 Nanosheets

Abstract

MoS2 nanosheets (NSs) have been found to possess the peroxidase-like activity and widely used in colorimetric sensors, but the catalytic active sites of MoS2 NSs are still blurred. Herein, MoS2 NSs with S 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 increased, accompanying by the decreasing of S/Mo atomic ratio. The increasing of S 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 S defects on their surface. Finally, the peroxidase-like activity of S 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

Keywords: MoS2 nanosheets, Peroxidase, Active site, Pyrophosphate, Sulfur defect