Design of MoS2/ZnO bridge-like hetero-nanostructures to boost triethylamine (TEA) sensing

Nano-heterojunctions play an important role in optimize semiconductor performances. Considering the different electron structure-related physical properties and their own sensing advantages of MoS2 and ZnO, we propose a noval semiconductor heterojunction based on MoS2/ZnO composites. Furthermore, the size and microstructure of the MoS2/ZnO composites are carefully designed by synthesis technique optimization. Here, the unique MoS2/ZnO bridge-like heterogeneous composite nanostructure composed of nanoflowers and nanosheets is prepared by two-step hydrothermal method. Further, MoS2/ZnO composites are characterized by using XRD, SEM, TEM, UPS and XPS. The MoS2/ZnO sensor is investigated for pollutant triethylamine (TEA) sensing applications. The gas sensitivity test shows remarkable response (31.08) to 100 ppm TEA at an optimum operating temperature (200 °C). Moreover, as compared with other interfering gases, it presents excellent selectivity to TEA and outstanding stability in air atmosphere within 5 weeks, besides the short response time (35 s) and recovery time (142 s) to 100 ppm TEA. The superiority of the sensor may be ascribed to the unique three-dimension self-assembly nanostructure and the formation of n-n heterojunctions. The MoS2/ZnO sensor with good performances verifies its good prospect in practical applications.