Detection of leaks of flammable methane (CH₄) gas in a timely manner can mitigate health, safety, and environmental risks. Zinc oxide (ZnO), a polar semiconductor with controllable surface defects, is a promising material for gas sensing. In this study, Ag–Ru co-doped into self-assembled ZnO nanorod arrays (ZnO NRs) was prepared by a one-step hydrothermal method. The Ag–Ru co-doped sample shows a good hydrophobic property as a result of its particular microstructure, which results in high humidity resistance. In addition, oxygen vacancy density significantly increased after Ag–Ru co-doping. Density functional theory (DFT) calculations revealed an exceptionally high charge density accumulated at the Ru sites and the formation of a localized strong electric field, which provides additional energy for the CH₄ reaction with ^•O₂^– at the surface at room temperature. Optimized AgRu_0.025–ZnO demonstrated an outstanding CH₄ sensing performance, with a limit of detection (LOD) as low as 2.24 ppm under free-heat and free-light conditions. These findings suggest that introducing defects into the ZnO lattice, such as oxygen vacancies and localized ions, offers a promising approach to improving the gas sensing performance.

中文翻译：

---

通过 Ag-Ru 共掺杂 ZnO 纳米棒的缺陷工程增强甲烷气体传感


及时检测可燃气体甲烷（CH ₄ ）气体的泄漏可以减轻健康、安全和环境风险。氧化锌（ZnO）是一种具有可控表面缺陷的极性半导体，是一种很有前途的气体传感材料。在这项研究中，通过一步水热法制备了Ag-Ru共掺杂到自组装ZnO纳米棒阵列（ZnO NRs）中。 Ag-Ru共掺杂样品由于其特殊的微观结构而表现出良好的疏水性，从而具有高耐湿性。此外，Ag-Ru共掺杂后，氧空位密度显着增加。密度泛函理论 (DFT) 计算表明，Ru 位点处积累了极高的电荷密度，并形成了局域强电场，为 CH ₄ 与 ^• 室温下表面的 O ₂ ^– 。优化的 AgRu _0.025 –ZnO 表现出出色的 CH ₄ 传感性能，在无热和无光条件下检测限 (LOD) 低至 2.24 ppm。这些发现表明，在 ZnO 晶格中引入缺陷，例如氧空位和局域离子，为提高气体传感性能提供了一种有前途的方法。