High-Sensitivity Room-Temperature Detection of HS Using ZnO/TiCT Nanocomposite: Potential Applications in Exhaled Gas Monitoring.

The detection of hydrogen sulfide (HS) in exhaled breath at room temperature is essential for health monitoring and disease diagnosis. This study investigates a ZnO/TiCT nanocomposite synthesized by combining ZnO nanoparticles, prepared by a hydrothermal method, with TiCT MXene. Experimental results demonstrate that the ZnO/TiCT nanocomposite sensors exhibit excellent HS detection performance at room temperature with high sensitivity, rapid response time, and robust recovery capability. Specifically, the ZnO/TiCT-1.0 wt % nanocomposite sensor shows a response of 85.116 at 5 ppm of HS, which is 14-fold and 35-fold greater than that of pure ZnO and TiCT MXene, respectively. The sensor exhibits a rapid response (50 s) and recovery time (115 s) at 100 ppb of HS. Additionally, it shows exceptional sensitivity to HS at low concentrations, with a detection limit as low as 1 ppb. Based on the excellent sensing performance, oral exhaled gas detection demonstrates that the sensor effectively differentiates HS levels in healthy and patient breath samples. These findings highlight the potential of the ZnO/TiCT nanocomposite in exhaled HS detection at room temperature, offering new insights for developing ultrasensitive biogas sensors.