High performance room temperature CO gas sensor based on CuO/TiO2/N-MWCNTs ternary nanocomposites.

[Display omitted] • The CuO/TiO 2 /N-MWCNTs sensor was prepared by hydrothermal method and calcination. • The CuO/TiO 2 /N-MWCNTs composites sensor has excellent sensing properties towards CO sensing. • The sensor performance for CO gas is further improved by the introduction of N-MWCNTs. The detection of dissolved gases in the oil of oil-immersed transformers is essential to evaluate the operating status of oil-immersed transformers. In this study, a CuO/TiO 2 /N-MWCNTs composites-based sensor was fabricated by hydrothermal method for the detection of dissolved CO gas in oil. The introduction of N-MWCNTs with high specific surface area, high electrical conductivity and multiple adsorption sites effectively improved the response value and response/recovery performance for CO. The response can reach 4.33 at a CO concentration of 50 ppm, which is 1.74 times higher than that of the CuO/TiO 2 sensor. In addition, the prepared sensor presents a fast response/recovery time (230 s/60 s) to CO, and has excellent selectivity and long-term stability. Finally, a multi-concentration CO alarm system was constructed through a reasonable circuit design. It is shown that the CuO/TiO 2 /N-MWCNTs-based sensor can achieve high-precision CO detection, which can provide a new idea for the detection of dissolved CO gas in the oil of oil-immersed transformers. [ABSTRACT FROM AUTHOR]