Use of CNT/Co3O4-SnO2 in a Carbon Monoxide Sensor Operating at Room Temperatures

Sensing materials of Co3O4-SnO2 system were prepared hydrothermal method. The prepared samples were characterized using temperature program reduction (TPR) technique. The resulting Co3O4-SnO2 material was used as a semiconductor p-type CO sensor. The mixture with a Co3O4-SnO2 ratio of 1:4 had the highest sensor response among various ratios of Co3O4-SnO2 at the working temperature. Various metals Au, Ag, Au and Pt were adding on the surface of Co3O4-SnO2 revealed no enhancement of the sensor response of the sensor. Doping 0.1% CNT into Co3O4-SnO2 enhanced the CO response of undoped Co3O4-SnO2. Addition of CNT increased the adsorption ability of the blended material and enhanced the sensor response. The sensor response was tested under CO concentrations ranging from 20 to 1000 ppm.