A CuO/TiO2 Heterojunction Based CO Sensor with High Response and Selectivity

The use of heterojunctions is a promising solution to the problem of cross‐sensitivity in gas sensors. In this work, a carbon monoxide sensor based on the CuO/TiO 2 heterojunction was designed and fabricated. Due to the good adsorption properties of CuO materials to CO, and the heterojunction interface charge transfer, the CuO/TiO 2 thin film sensor exhibits high sensitivity to CO at room temperature. The response is as high as 10.8–200 ppm CO, about 10 times its response to H 2 . Interference from H 2 is greatly reduced by optimizing the structure of the CuO/TiO 2 heterojunction. This reliable detection of carbon monoxide with excellent discrimination against H 2 is of great significance for the development of CO gas sensors.