上海科技大学知识管理系统

Methane (CH4) sensors based on metal oxide semiconductors are widely used for both safety and environmental applications. The need of further improvements in performance provides great motivation for the search of novel sensing materials and strategies. Herein, CH4 sensor based on samarium nickelate (SmNiO3, SNO), a complex perovskite oxide, was developed. Under exposure to CH4, SNO exhibited a large sensitivity arising from metal-insulator transition induced by electron doping, which was a fundamentally different strategy from the carrier depletion or accumulation on the surface of the conventional metal oxide semiconductors. The electronic phase transition was confirmed by both X-ray characterization and electrochemical impedance spectroscopy measurements. In addition, the SNO exhibited a mixed ionic and electronic conductivity in the CH4 environment. The kinetics of phase transformation was modeled with the Johnson-Mehl-Avrami equation.The performance of SNO-based CH4 sensors were also carefully evaluated. Overall, the electron doping-induced metal-insulator transition was demonstrated as a promising alternative strategy for CH4 sensing.