Light-Activated Room Temperature Surface Acoustic Wave H₂S Sensor Based on Bi₂S₃ Nanoribbons

The expansion of the Internet of Things (IoT) has rendered wireless passive, highly stable, and room-temperature gas sensors indispensable for sensor applications. In this work, a room-temperature surface acoustic wave (SAW) H₂S sensor based on a thin film of nano-mesh woven with Bi₂S₃ nanoribbons was successfully designed and prepared. The impact of varying inorganic salts solution ligand substitution of long-chain organic ligands of Bi₂S₃ films on performance was assessed. Notably, the responses of the sensors following ligand substitution exhibited improvement to varying degrees. In particular, the Cu(NO₃)₂-treated sensor to 10 ppm H₂S was 203% of that of the untreated sensor. Furthermore, the impact of visible light activation on sensor performance was assessed. The results show the sensor has a high sensitivity to H₂S molecules under yellow light activation at room temperature, with excellent selectivity, fast response speed and low detection limit. The sensor exhibited a response to 10 ppm H₂S under yellow light activation that was approximately equal ~ two times greater than the response observed in a dark environment. This work provides a novel approach to enhance the performance of room-temperature SAW H₂S sensors.