In this study, CuO was grown in situ on rGO nanosheets using a microwave‐assisted method and constructed CuO/rGO heterojunction materials. The material was drop‐coated onto silver electrodes on a polyimide (PI) film substrate to fabricate a flexible gas sensor. The crystal structure, microstructure, and elemental composition of the material were characterized by XRD, SEM, TEM, EDS, and BET. The material exhibited excellent selectivity for H 2 S. The sensor exhibited a response value of 32–50 ppb H 2 S at room temperature, which is three times that of pure CuO, and maintained its response performance without degradation over a continuous 12‐day testing period. The enhancement of gas‐sensitive sensing performance is attributed to the formation of heterojunctions between CuO and rGO, which promotes the transport of charge carriers, increases the specific surface area, provides more adsorption sites on the material's surface, accelerates the response speed, and improves sensing performance. The prepared flexible gas sensor still maintains 70.9% of its maximum response after 2000 bending cycles, demonstrating excellent mechanical durability.
Li et al. (Mon,) studied this question.