Sensitive Xylene Gas Sensor Based on NiO-NiCo2O4 Hierarchical Spherical Structure Constructed With Nanorods

Xylene is widely present in production and life, and its volatility has adverse effects on environmental quality and human health. Therefore, the research on xylene sensors is very necessary. In this paper, the xylene sensors based on NiO-NiCo
₂
O
₄
(NNC) nanocomposites were constructed by means of screen printing. By adding different amounts of cobalt source, the xylene sensing characteristics of the sensors were studied at room temperature (RT) of 25°C and relative humidity (RH) of 43%. The NNC sensor with a 4:1 molar ratio of Ni source and Co source to 50 ppm xylene had more than doubled the response than the pure NiO, and it exhibited excellent selectivity, response/recovery speed, stability and the low detection limit of xylene (0.5 ppm). In addition, the anti-humidity interference ability of the NNC sensor was studied. Finally, the sensing mechanism of the NNC film sensor was discussed.