In-situ grown CuO/TiO2 vertical bilayer nanorods array for sensitive CO detection at lower temperature

CuO is a typical p-type semiconductor with the advantage of narrow bandgap, making it a gas sensing material for detecting CO gas at lower operating temperatures.However, the poor response value limits its application. As a classical wide-band gap n-type gas sensing metal oxide semiconductor, TiO 2 has the advantages of high response to CO. However, high operating temperature becomes the big obstacle to overcome. Therefore, sensitive CO detection at lower temperature will be achieved by integration of CuO with TiO 2 . In this paper, in-situ two step hydrothermal method was used to prepare CuO/TiO 2 vertical bilayer nanorod arrays grown in situ. The gas sensing results show that the response value of the CuO/TiO 2 vertical bilayer nanorod arrays is 6.1 times (14.9, 300 ppm) higher than that of single CuO nanotentacle arrays (2.1, 300 ppm), and the operating temperature is reduced to 100 °C compared with pure TiO 2 nanorod arrays (360 °C). This strategy provides a new idea for the fabrication of CO gas sensors with high response and low operating temperature.