The Novel CO sensing material CoOOH–WO3 with Au and SWCNT performance enhancement

Various ratios of CoOOH–WO3 sensing materials were prepared from CoOOH and tungstic acid in air. Au and single wall carbon nanotube (SWCNT) were also added to CoOOH–WO3 materials to detect CO concentration. The prepared samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and temperature program reduction (TPR) techniques. The resulting CoOOH–WO3 material was used as a semiconductor p-type CO sensor. The mixture with a CoOOH–WO3 ratio of 2:1 had the highest sensor response, and the sensor head worked at room temperature. Doping 1 wt% SWCNT and 0.1 wt% Au into 2:1 CoOOH–WO3 boosted the CO response about 3.6 times, and the response time was 90 s. An explanation for the CO sensor's characteristics was proposed with reference to the adsorption, desorption, and surface reaction processes of CO.