Highly selective nitrogen dioxide gas sensing of ReS2 nanosheets: A first-principles study

Rhenium disulfide (ReS2) is considered a promising material for the detection of nitrogen dioxide (NO2) gas due to its adjustable structure and unalterable bandgap. However, the atomic-scale gas sensing mechanism of ReS2 has still not been revealed and is difficult to determine using currently available experimental technologies. In this work, an approach for evaluating the selective NO2 sensing performance of ReS2 is proposed and investigated by first-principles calculations. Based on adsorption properties, charge transfer, density of state, I-V relationship and recovery time, ReS2 shows a superior selective sensitivity and fast response to NO2 compared to NH3, CH3OH, CH3COOH, C2H5OH and CH3COCH3 gases, which is consistent with the experimental results. ReS2 ex-hibits high current sensitivities of 29.81% and 23.01% to NO2 with bias voltages of 0.5 V and 0.8 V, and the selectivity of NO2 compared to the other gas ranges from 5.7 to 7.3, suggesting the high selectivity of ReS2 toward NO2 gas. Our analysis framework provides a conceptual foundation for designing nanomaterial-based gas sensors.