Methane Sensors Based on Lithium Doped Porous Materials for Coal Mine Safety Application

Two kinds of methane sensors based on lithium-montmorillonite (Li-MMT) or lithium-cyclodextrin (Li-CD) have been developed, and they have been further modified by adding a small amount of carbon nanotubes (CNTs). The sensitivity of the sensors increases linearly with methane content in the concentration range of 50–500 ppm. Other characteristics of the sensors such as response time, gas selectivity, and stability have been investigated as well. The results indicate that all the sensors response quickly, show good sensitivity and selectivity to methane. Li-MMT/CNTs sensor has highest sensitivity towards methane, and Li-CD sensors have certain resistance to dust and humidity, showing great advantages in coal mine safety application.