One-Step Electrospun WO/CuO p-n Heterojunction Nanocomposites for Ultrasensitive and Rapid HS Detection.

Hydrogen sulfide (HS), a critical industrial gas, exhibits high toxicity, flammability, and strong corrosiveness, posing severe health risks at elevated concentrations. Consequently, developing highly sensitive and rapid-response detection methods is imperative. In this study, WO/CuO nanocomposites were synthesized via a one-step electrospinning technique, enabling the fabrication of high-performance HS gas sensors. The gas-sensing properties of WO/CuO nanocomposites for HS detection were systematically investigated. The composite sensor demonstrated optimal performance at 150 °C, with a CuO mass fraction of 5 wt % yielding the highest HS response. For 5 ppm of HS in air, the WO/CuO sensor exhibited a response value of 68.43%, with a rapid response time of 24 s and recovery time of 78 s at 150 °C. The enhanced HS sensing performance is attributed to the formation of p-n heterojunctions at the WO/CuO interface, which improves long-term stability. This mechanism was corroborated by in situ TEM and XRD analyses. Furthermore, the unique interaction between CuO and HS enhances low-concentration detection sensitivity. First-principles calculations revealed that the performance improvement arises from CuO sensitization effects and heterojunction formation. These findings provide novel insights and a theoretical foundation for advancing high-reliability gas sensor technologies.