Pt-modified nanosheet-assembled SnS2 hollow microspheres for low temperature NO2 sensors

The three-dimensional (3D) microstructures assembled by nanomaterials have attracted great attention due to their unique hierarchical structure and large surface area. In this study, the hierarchical nanosheets-assembled SnS 2 hollow microspheres with an average diameter of 6.1 μm were synthesized via a facile hydrothermal method . Then Pt nanoparticles were deposited on the surface of SnS 2 to form Pt/SnS 2 nanocomposites using the in-situ reduction method. Compared with pristine SnS 2 -based sensors, the Pt/SnS 2 sensors exhibited improved gas-sensing performances to NO 2 gas, including higher sensitivity, shorter response time , and better selectivity . The superior sensing performance can be ascribed to the Schottky junction created between Pt and SnS 2 , along with the catalytic effect of Pt. Moreover, the adsorption energy of SnS 2 and Pt-modified SnS 2 for NO 2 molecules was calculated using first principles based on density functional theory (DFT). The Pt modification can enhance the interaction of NO 2 with the SnS 2 surface, which is favorable for improving the gas-sensing properties. This work provides novel hierarchical SnS 2 microspheres based gas sensors for NO 2 detection.