Over the past several decades, metal oxide based gas sensors are widely used for hydrogen gas sensing applications. However, their poor sensitivity and very high value of operating temperature (> 300 °C) pose a severe threat over hydrogen detection due to its highly flammable nature. In recent years, a few strategies have been explored by the researchers to address these formidable challenges faced by the sensing technology. Here, we present MoS ₂ /ZnO hybrid exhibiting higher molecular detection at low operating temperature. The ZnO film was grown using the magnetron sputtering technique, while MoS ₂ -PVP nanocomposites (MoS ₂ -PVP NCs) were synthesized through organic polymer assisted liquid exfoliation process. We examined the sensing performance of various MoS ₂ /ZnO hybrids prepared by the decoration of different concentration MoS ₂ -PVP NCs over the ZnO surface. The decoration of ZnO film through MoS ₂ -PVP NCs increases the effective surface area and the number of active sites for the hydrogen molecules to get adsorbed, hence improved the surface reactivity to gas molecules. Interestingly, a 5 mg/mL MoS ₂ -PVP NCs decorated ZnO sensor showed an improvement of $\sim 8$ times in sensing response as compared to the pristine ZnO based sensor upon 50 ppm hydrogen exposure. The improvement in sensing ability is primarily ascribed to electronic sensitization and spillover effects. Our results establish that the MoS ₂ /ZnO hybrid exhibit superior hydrogen sensing behavior indicating the prominent role of MoS ₂ -PVP NCs in hydrogen detection.

中文翻译：

---

MoS ₂ -PVP纳米复合材料装饰的ZnO微片，用于高效氢气检测

在过去的几十年中，基于金属氧化物的气体传感器被广泛用于氢气传感应用。然而，由于其高度易燃的性质，它们灵敏度低和工作温度值很高（> 300°C）严重威胁着氢气的检测。近年来，研究人员已经探索了一些策略来应对传感技术面临的这些严峻挑战。在这里，我们提出了MoS ₂ / ZnO杂化物在较低的工作温度下表现出更高的分子检测能力。ZnO膜使用磁控溅射技术生长，而MoS ₂ -PVP纳米复合材料（MoS ₂ -PVP NCs）是通过有机聚合物辅助液体剥离工艺合成的。我们检查了 通过在ZnO表面上 装饰不同浓度的MoS ₂ -PVP NC制备的各种MoS ₂ / ZnO杂化物 的传感性能 。通过MoS ₂ -PVP NCs对ZnO膜的装饰 增加了有效表面积和氢分子被吸附的活性位点的数量，从而提高了对气体分子的表面反应性。有趣的是，用5 mg / mL MoS ₂ -PVP NCs装饰的ZnO传感器显示出了改善的 $ \ sim 8 $ 与原始ZnO基传感器在50 ppm氢气暴露下相比，在响应速度上提高了两倍。感测能力的提高主要归因于电子敏化和溢出效应。我们的结果表明，MoS ₂ / ZnO杂化物表现出优异的氢感测行为，表明MoS ₂ -PVP NCs在氢检测中的重要作用 。