Highly stable and sensitive NO2 sensor based on Bi2S3 with synergistic effect of multi-scale structure and Pt nanoparticles sensitization over a wide humidity range

NO 2 is a prevalent atmospheric pollutant known to cause significant harm to both the environment and human health. In practical applications, the development of NO 2 sensors capable of functioning over a wide humidity range with high sensitivity and stability is crucial. Here, the Pt-decoration multi-scale three-dimensional Bi 2 S 3 nanoflower structure assembled by one-dimensional nanorods and two-dimensional reticulated nanomeshes was constructed by integrating the geometrical and electronic effects. The Pt/Bi 2 S 3 based sensors exhibit a high response of 3.92 and rapid response/recovery times of 15 s/136 s to 1 ppm NO 2 at room temperature. Furthermore, the Pt/Bi 2 S 3 based sensors show excellent selectivity and stability across a wide range of humidity levels (10 %-90 %RH). Finally, a portable NO 2 detector was designed for data acquisition and wireless transmission to enable real-time gas detection and hazard warning. Our study presents a multi-scale structure for sensitive materials design and practical application of high-performance NO 2 sensors operated in a wide humidity range at room temperature.