A Catalytic Carrier Gas Sensor Based on a Nanotube Array

Abstract

To effectively monitor methane in coal mine environments, a new type of catalytic carrier gas sensor based on a nanotube array was designed and fabricated. The sensor consists of a catalytic carrier based on a nanotube array, a sensitive Pt electrode, leading wires made from Ag/Pd alloy, a standard two-pin tube shell, powder metallurgy sheets and other components. The metallurgical copper powder sheets make the sensor explosion-proof. The desired catalytic carrier based on a Al2O3 nanotube array was prepared by chemical deposition on a nanoporous carrier film. The sensitive Pt electrode was prepared by a thick-film printing process via impregnation with a chloroplatinic acid and palladium chloride solution to form the noble metal catalyst. The results show that for methane concentrations in the range of 0% to 3%, the measured output is approximately 73 5 mV, the response time is 6 seconds, and the recovery time is 5 seconds. When the CH4 concentration is in the range of 0~3.81%, the response voltage of the sensor and the concentration of CH4 exhibit a good linear relationship. The stability of the sensor was examined in a 2% CH4 environment, and the stability of the sensor drifted 0.15% after 60 days.