LAUSR

Hydrogen sulfide (H2 S) detection with high selectivity and low working temperature is of great significance due to its strong toxicity to the environment and human and also as an endogenous signaling molecule existing in various physiological processes. Two-dimensional (2D) perovskites with high carrier mobility are promising candidates for gas sensing, however the development of stable and nontoxic 2D perovskites nanosheets still remains a challenge. Herein, 2D all-inorganic NbWO6 perovskite nanosheets with thicknesses down to 1.5 nm are synthesized by liquid exfoliation, and for the first time, the gas sensing performance based on the ultrathin nanosheets are investigated. The few-layer NbWO6 -based sensor exhibits fast H2 S sensing speed (< 6 s) with high selectivity and sensitivity (S = 12.5 versus 50 ppm) at low temperature (150°C). A small variation of H2 S concentration (< 0.5 ppm) can be detected with fully reversible resistance signal. This work sheds light on the development of high-performance gas sensor working in ambient condition based on low-dimensional, nontoxic and wide-bandgap perovskite semiconductor. The high carrier mobility, ultrathin structure and soft peculiarity make this type of 2D perovskite semiconductor an ideal material candidate for the fabrication of flexible, transparent and wearable sensing device in the future. This article is protected by copyright. All rights reserved.