Near-infrared enhanced SnO2/SnSe2 heterostructures for room-temperature NO2 detection: Experiments and DFT calculations

A photo-activated semiconductor gas sensor presents a promising strategy for detecting highly toxic nitrogen dioxide (NO2) gases at room temperature. Near-infrared enhanced gas sensor may offer a new strategy for room-temperature NO2 detection. In this work, MOF-based SnO2/SnSe2 heterostructures prepared by a solvothermal method were used to probe NO2 gas at room temperature. Under near-infrared irradiation, the SnO2/SnSe2 sensor exhibits a response/recovery time of 23/7 s and a sensitivity value of 1500 for NO2 at room temperature. In addition, the adsorption behavior between SnO2/SnSe2 and gas molecules was further studied by first-principles calculations. The optimization of the gas-sensing performance was explored by considering the photoexcited electrons and the heterostructure. This work highlights the potential of SnO2/SnSe2 heterostructures as high-performance NO2 sensors operating at room temperature, as well as the enhanced activation effect of near-infrared irradiation on semiconductor gas sensors.