Novel rGO decorated ZnO/BiVO4 heterojunction for enhancement of NO2 sensing properties
The ZnO/BiVO4 heterojunction has been firstly prepared by the co-precipitation and hydrothermal methods, then the rGO nanosheets decorated on heterojunction by a simple hydrazine hydrate reduction to construct a novel ZnO/BiVO4/rGO composite based NO2 sensor. The structure, morphology and gas sensing performance of the composite were characterized and measured by various spectra and gas sensing test. Compared to the previously reported same kind of gas sensors, the sensor exhibits competitive sensing performance with a maximum response of 126.64 to 1 ppm NO2 at an operating temperature of 95 °C, which is 5.7 times and 2.4 times higher than ZnO and ZnO/BiVO4 junction, respectively. Also, the sensor has rapid response and long-term stability to NO2 compared with pure ZnO. The good sensing properties ascribe the formation of the n-n heterojunction between ZnO and BiVO4 and the decoration of rGO.