Construction of highly efficient In2O3/SnO2 sensor for real-time NO2 monitoring at near room temperature

NO2 is a dangerous gaseous pollutant, which is also a precursor to the formation of photochemical smog and ozone. It has negative impacts on the environment and human beings at local, regional and even the whole global scale. In this context, it is imperative to develop the efficient sensing materials for detecting NO2 gas. In this study, a near room temperature NO2 sensing material (In2O3/SnO2 heterostructure) with "4S" index (selectivity, sensitivity, speed, stability) was constructed, it overcomes the drawbacks of traditional detection techniques and solves the unavoidable problems of metal oxide semiconductors in the sensing process (high temperature, cross response, weak response at low concentration, etc.). Meanwhile, the synergy between the surface structure and heterostructure interface of In2O3/SnO2 has been thoroughly analyzed. More importantly, this study also sampled and monitored ambient air samples from different geographical locations and different time points in cities, which provides strong support for promoting the application of MOS sensors in real environment.