Metal-oxide semiconductors for carbon monoxide (CO) gas sensing: A review

The development of metal-oxide semiconductor (MOS) based gas sensor has engrossed demanding research interest in the last several decades because of their potential for the selectivity, high sensitivity and fast detection of various toxic gases. Carbon monoxide (CO) is odorless, colorless and one of the most toxic gases. In this review recent progress on the development of different MOS based nanostructure for CO gas sensor is summarized. The commonly investigated classes of materials are MOSs (notably, zinc oxide and tin oxide) and yttrium stabilized zirconium. Recently, many metal oxide semiconductor including tin oxide, zinc oxide, titanium oxide, indium oxide, tungsten oxide, cerium oxide, copper oxide, composite MOS etc have been tested for CO gas sensing. The main focus is on new approaches for the synthesis of CO gas sensor by various researchers to improve the sensing performance like selectivity, sensitivity, response and recovery time with different materials and catalysts used.