An oil-immersed transformer is a critical electrical device for power delivery. Online monitoring of transformer operation is the key to ensuring the regular operation of power systems. This paper proposes Au/ZnO, Pd/ZnO, and Pt/ZnO heterojunctions as new gas-sensitive materials and investigates their gas-sensitive performance to dissolved gases (C₂H₄, CO, and H₂) in transformer oil. Upon theoretical density functional theory (DFT) calculations, the analysis of the total density of states (TDOS), partial density of states (PDOS), molecular orbital theory, and charge deformation density reveals that Au, Pd, and Pt form heterojunctions with ZnO, which enhance the electrical conductivity of the system. Meanwhile, intrinsic ZnO is unsuitable for gas detection and adsorption, while the Au/ZnO heterojunction suits C₂H₄ detection. In contrast, the Pd/ZnO heterojunction is suitable for H₂ detection, and the Pt/ZnO heterojunction is suitable for C₂H₄ and CO detection. The electrical conductivity of the adsorption models is changed to varying degrees after gas adsorption. The different change rate electrical conductivity just serves as a theoretical foundation for determining the type and concentration of dissolved gases in transformer oil. The research results act as a theoretical foundation for constructing gas sensors with a ZnO-based material.

中文翻译：

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变压器油中溶解气体金属（Au、Pd、Pt）/ZnO异质结气体传感器的气敏性能研究

油浸式变压器是电力输送的关键电气设备。变压器运行在线监测是保证电力系统正常运行的关键。本文提出Au/ZnO、Pd/ZnO和Pt/ZnO异质结作为新型气敏材料，并研究了它们对变压器油中溶解气体（C ₂ H ₄、CO和H ₂ ）的气敏性能。通过理论密度泛函理论（DFT）计算、总态密度（TDOS）、部分态密度（PDOS）、分子轨道理论和电荷变形密度的分析表明Au、Pd和Pt与ZnO形成异质结，这增强了系统的导电性。同时，本征ZnO不适合气体检测和吸附，而Au/ZnO异质结适合C ₂ H ₄检测。相比之下，Pd/ZnO异质结适合于H ₂检测，而Pt/ZnO异质结适合于C ₂ H ₄和CO检测。气体吸附后吸附模型的电导率发生了不同程度的变化。电导率的不同变化率只是作为确定变压器油中溶解气体的类型和浓度的理论基础。研究结果为构建ZnO基材料气体传感器奠定了理论基础。