Abstract: Coal mine gas is the main cause of safety accidents in China′s coal mines and related metal mines. Methane, as the main component of coal mine gas,can be effectively monitored and alerted in a timely manner using high-performance gas sensors,which can guarantee the safety of underground mining operations. Metal oxide semiconductor gas sensors have several advantages,including low cost,compact size,excellent stability and rapid response,as compared to alternative gas sensors such as electrochemical,gas chromatography,catalytic combustion and optical sensors. These advantages contribute to the extensive range of applications and promising prospects associated with MOS gas sensors. This paper introduces several common metal oxide semiconductor methane gas sensitive materials,analyzes their methane gas sensing principles and advantages,and concludes that morphology regulation,noble metal doping,and heterogeneous junction construction are the main three directions for enhancing metal oxide semiconductor gas sensor sensitivity performance. There is a need to further optimize the preparation around three gas-sensitive enhancement mechanisms such as surface resistance control,chemical sensitization and electronic sensitization. All in all,metal oxide semiconductor gas-sensitive materials research provides the foundation for developing highperformance gas sensors vital for helping guarantee mine safety and sustainable production.

Key words: methane detection,metal oxide semiconductor,gas sensor,gas sensing materials,coal mine safety