Hydrophobic ZIF-8 grown on PdPt/WO3 nanocomposite: Surface growth mechanism and molecular sieving effect for room-temperature hydrogen detection under high-humidity conditions

Hydrophobic ZIF-8 was grown on PdPt/WO 3 for room‑temperature H 2 detection under 90% RH. • ZPPW-2.0 sensor achieved ultrahigh response (15976.29) to 5000 ppm H 2 at 25℃ under 90% RH. • Dual sieving provided excellent selectivity against interfering gases. • Red‑light excitation enhanced sensitivity via oxygen‑vacancy activation. • Multi‑mechanism design ensured humidity‑tolerant and stable performance. This study presented the development of a room-temperature hydrogen (H 2 ) gas sensor, designated ZPPW-2.0, capable of operating reliably under high-humidity conditions. The sensor structure was constructed by growing hydrophobic zeolitic imidazolate framework (ZIF-8) on a PdPt-modified WO 3 sensing film. This configuration enabled a synergistic surface regulation mechanism involving molecular sieving, surface defect engineering and photoexcitation-enhanced surface reactivity. Under ambient operating conditions (25°C, 90% relative humidity), the sensor exhibited a remarkable response of 15976.29 to 5000 ppm H 2 , a response time of 8 s, excellent repeatability, long-term stability, and outstanding selectivity. Furthermore, illumination with 655–660 nm red light could enhance performance. The observed high performance was attributed to the synergistic enhancement by surface defect states, effective exposure of surface active sites, inhibition of surface water competition, and molecular sieving. This work highlighted the central role of surface reaction, and interfacial regulation in designing reliable room-temperature H 2 sensors for humid environments. Download: Download high-res image (274KB) Download: Download full-size image