The investigation and DFT calculation on the gas sensing properties of nanostructured SnO2

The performance of SnO2 as a sensor of gaseous ethanol was experimentally and theoretically investigated. SnO2 particles were synthesized via a hydrothermal method. A side-heated sensor was fabricated and its sensing properties for various vapors were experimentally tested. The influence of the nanostructure and morphology of SnO2 particles on their sensing ability was also investigated. The results suggest that hollow-sphere structured SnO2 has a better sensing performance than other morphologies. Under an operating temperature of 330 °C, the response of SnO2 to ethanol gas was found to be ~68 times higher than that of the other tested gases. Additionally, a general mechanism describing the performance of the SnO2 sensor in the presence of gaseous ethanol is presented, and supported by density functional theory (DFT) calculations to explore the electrical properties of bulk SnO2 and its (110) surface. It is suggested that SnO2-based nanostructured materials can be employed in selective and efficient sensors of gaseous ethanol.