Catalytic Combustion Type Carbon Monoxide Sensor Based on CuO-Co3O4 Catalyst

Composite material CuO-Co3O4 was prepared by a co-precipitation method. A catalytic combustion CO sensor was fabricated by using CuO-Co3O4 as the sensing material and NTCT (Negative Temperature Coefficient Thermistor) as the heating resistance. The limit of quantification for the sensor is 0.034 9 mg.L-1. The phase composition and surface morphology of the composite material were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). When the calcination temperature of CuO-Co3O4 is 400 degrees C, the sensor's sensitivity to CO reaches maximum. The sensor shows good linear relationship between response signals and CO concentration from 0.034 9 to 0.582 mg.L-1 at the operating voltage of 9 V and the linear correlation coefficient is 0.979. The 90% response and recovery time to 0.582 mg.L-1 CO is 24 s and 68 s, respectively.