Gas Sensors Based on SnO2 Nanomaterials toward Hazardous Gases Detection

So far, the issue of environmental pollution caused by the abnormal level of toxic, flammable gases in the air has attracted much attention, and developing a reliable gas sensor for sensitively and selectively detecting different hazardous gases is significant. Among various sensor materials, tin oxide (SnO2), a representative wide bandgap (Eg = 3.6 eV) semiconductor for n-type, has been considered as the best choice of sensing materials to efficiently monitor and detect hazardous gas, which can attribute to the advantages with excellent physicochemical properties, good chemical stability, nontoxicity and low cost, etc. However, the sensor made from traditional SnO2 material still has some disadvantages concerning lower sensitivity, higher power consumption, slower response/recovery, and poor selectivity for other interferential gases, these limit it widely in practical applications. In this chapter, the significant improvements of SnO2-based sensors’ performances to different hazardous gases have been achieved by designing and tuning unique morphologies and compositions via synergic different methods (such as hydrothermal route and template-assisted). Besides, the strategies that further improve the sensing performances including the elements doping, surface functionalization, and composited with other materials also have been discussed. Besides, the basic knowledge of semiconductor-based gas sensors is also briefly introduced.