Room-temperature sensing performance of Pt nanoparticles modified In2O3@ZnS core-shell hollow nanospheres to n-butanol

Abstract

Room-temperature detection is a great pursuit of goal for semiconductor sensors, aiming to lower energy consumption, prolong the lifetime of sensors, and mitigate safety risks. In this study, room-temperature sensing materials, made of novel Pt nanoparticles modified In2O3@ZnS core-shell hollow nanospheres (Pt-In2O3@ZnS CSHNs), were synthesized by simple hydrothermal and in-situ reduction methods without using any surfactants or toxic organic solvents. The effects of the morphology and composition on gas sensing performance were systematically investigated by adjusting the content of Pt nanoparticles. These materials exhibited excellent sensing performance towards n-butanol at (near) room temperature (~25 °C). The optimal working temperature of Pt-In2O3@ZnS CSHNs (50 °C) was decreased by 210 °C than that of In2O3@ZnS (1:1) CSHNs (260 °C) towards 100 ppm of n-butanol. In particular, the 5% Pt-In2O3@ZnS CSHNs showed an excellent sensing response towards different concentrations of n-butanol at room temperature. The highest sensing response of Pt-In2O3@ZnS CSHNs was up to 7.1 (at 50 °C) and 6.2 (at 25 °C) for 100 ppm n-butanol with a short response time. Further studies demonstrated that such enhanced performances were possibly owing to the “catalytic sensitization” effect driven by Pt NPs and the “electronic sensitization” effect triggered through the formation of Pt-ZnS Schottky junction and In2O3/ZnS n-n heterojunction. This study may shed light on promising gas sensing materials to achieve the room-temperature detection of n-butanol in practical application.