UV-light-assisted NO2 gas sensor based on WS2/PbS heterostructures with full recoverability and reliable anti-humidity ability

Abstract

Abstract Transition metal dichalcogenides (TMDs) have blazed a novel trail in the field of NO2 gas detection owing to the unique photoelectric properties and prospective gas sensing performance especially working at low operating temperature. However, the incomplete recoverability and susceptibility to humidity at room temperature restrict the practical applications of TMDs-based gas sensors. Herein, we demonstrate a fully recoverable WS2 based gas sensor with enhanced anti-humidity ability by combining the decoration of zero-dimensional PbS nanoparticles and the assistance of UV light. Through the control over the molar ratio of WS2/PbS, the optimized WS2/PbS (the molar is 10:1) gas sensor exhibits a remarkable elevated recovery rate from 33.4% to 99.8% with almost no baseline drift as compared to that in the pure WS2 gas sensor. More importantly, attributing to the irradiation of UV can accelerate the desorption of water molecules, WS2/PbS heterostructure based gas sensor manifests more stabilized anti-humidity performance with stable initial resistance and negligible response value drift (8.8%) in the range of 10%–90% relative humidity. Furthermore, UV-assisted WS2/PbS gas sensor also possesses prominent sensing performances including high sensitivity, low detection limit (∼20 ppb), favorable selectivity and outstanding long-term stability. This research will pave the way on designing high-performance TMDs-based gas sensors operating at room temperature.