High-performance ethanol gas sensor with fast response/recovery rate based on the construction of SnO₂-CdS heterojunction

In this study, SnO2-modified CdS microspheres were prepared with simple two-step solvothermal method for first application in ethanol gas sensor. Compared with the pristine CdS-based sensor, the sensor containing 1 mol% SnO2 has superior ethanol sensing performance, and the response can achieve 130 for 100 ppm ethanol gas at the optimal working temperature of 200 degree celsius, with a response/recovery time just 21 s/3 s. This sensor has excellent selectivity for ethanol gas and good long-term stability. XRD, XPS, SEM, and TEM were used to characterize these gas-sensitive materials. The enhancement in gas-sensitive properties may relate to the SnO2-CdS heterojunction formation as well as the improvement in the specific surface area of composites.