Enhanced sensing of sulfur hexafluoride decomposition components based on noble-metal-functionalized cerium oxide

Abstract

Metal oxide semiconductors (MOSs) are widely used gas-sensing materials because of their large response values and fast response speed. However, high operating temperature hinders the development of MOS-based gas sensors. To detect SF6 decomposition components (including H2S, SO2, SOF2, and SO2F2), here, we have synthesized cerium oxide nanoparticles (CeO2 NPs) via a facile hydrothermal routine, followed by functionalization with Au, Ag, and Pd noble metals to improve sensor performance. Our developed CeO2-based sensor exhibited high response to target gases at a low working temperature. After doping various metals into the CeO2 NPs, we acquired distinct patterns of dynamic responses for SF6 decomposition components. Au functionalization could maximize the enhancements of sensor responses to H2S (976%), SO2 (153%), and SOF2 (151%) at 100 °C, and a Pd-modified CeO2-based sensor exhibited optimal response to SO2F2 at a relatively high temperature of 250 °C. In addition, high response values, short response–recovery times, good repeatability, and low detection limits were also obtained from CeO2-based sensors. Our results verified that doping different noble metals into CeO2 NPs should be a promising strategy to design high-performance gas sensors for SF6 decomposition component detection. Keywords: Gas sensor, CeO2, Noble metal functionalization, SF6 decomposition components