One-step calcined equiatomic W and Zn precursors to synthesize heterojunction of ZnO/ZnWO4 for NO2 detection

The composite of 6ZnO/ZnWO4-rGO (0.6 wt%) nanorods was successfully synthesized by one-step calcined equiatomic W and Zn precursors followed by reduced GO for detection of NO2. The morphology and structure of the composite were characterized by various spectroscopic technologies. The gas sensing test results showed that the composite exhibits linear, high and rapid response, the highest response reaches up to 45.38 that are 2.32 times of ZnO nanorods and the response and recover times are short to 35 s and 39 s at 110 ℃, and has high selectivity. The mechanism enhanced gas sensing was also discussed in detail, which is attributed to regulating and accelerating interface electron transfer and providing more active sites for gas adsorption due to the formation of heterojunction and the decoration of rGO. The work has reference significant for preparing bimetal oxide composite based sensors.