A <scp>CuO</scp>/<scp>TiO<sub>2</sub></scp> Heterojunction Based <scp>CO</scp> Sensor with High Response and Selectivity
Wei Wei, Huanhuan Zhang, Tiyue Tao, Xiaohong Xia, Yuwen Bao, M. A. Lourenço, K.P. Homewood, Zhongbing Huang, Yun Gao
Abstract
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.