Xylene is not only a carcinogenic gas, but also one of indoor pollution gases. Therefore, it is indispensable to develop a xylene gas sensor with fast response and high sensitivity. In this paper, 5 wt%rGO-Fe 2 (MoO 4 ) 3 -1 wt%Pt gas sensitive material was prepared by integrating the excellent properties of reduced graphene oxide (rGO) and noble metal Pt. In addition, the microstructure, elemental composition, phase and crystal structure of 5 wt%rGO-Fe 2 (MoO 4 ) 3 -1 wt%Pt nanocomposites were characterized. The nanostructure of Pt-modified Fe 2 (MoO 4 ) 3 nano-hollow spheres compounded on rGO was successfully prepared. The gas sensitive experiment results showed that 5 wt%rGO-Fe 2 (MoO 4 ) 3 -1 wt%Pt had better gas sensitive performance than Fe 2 (MoO 4 ) 3 (FMO), FMO-1 wt%Pt and 5 wt%rGO-FMO. At the optimum working temperature (175℃), the 5 wt%rGO-FMO-1 wt%Pt sensor had a maximum response value to xylene, and could detect 500 ppb xylene. In addition, the 5 wt%rGO-FMO-1 wt%Pt nanocomposite showed a rapid response and recovery process to xylene. Moreover, the gas sensitivity mechanism and enhancement of gas sensitivity of 5 wt%rGO-FMO-1 wt%Pt to xylene were systematically analyzed. The 5 wt%rGO-FMO-1 wt%Pt gas sensor prepared provided a new reference for the detection of xylene.
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.
危险品化学品经营许可证（带存储）