Metal oxide semiconductor-based methane sensing

Real-time and sensitive detection of methane (CH₄) is vital to the safety of life and production due to the explosivity and greenhouse effect of methane. Currently, metal oxide semiconductor (MOS)-based chemiresistive sensors are considered as an effective approach for their low cost, highly tunable structures, and easy fabrication. However, disadvantages like high working temperature, low sensitivity, and unsatisfying selectivity limit their potential wide application. In order to achieve the goal of high-performance MOS-based methane sensors, in this review, from the basic mechanism of MOS-based gas sensing and the property of methane, possible strategies of improving methane sensing performances in multiple aspects have been summarized systematically, including sensitivity, selectivity, stability, and humidity resistance. Recent progress in the research and development of metal oxide semiconductor-based methane sensor technology is also surveyed in this review. Finally, the future trends and perspectives of MOS-based chemiresistive methane sensors are proposed.