Sensing and Adsorption for Transformer Oil-dissolved Gases by Rh-doped TiO 2 : First-Principle Study

Detecting oil-dissolved gases (H2, C2H2and CH4) in transformers is increasingly important, which is beneficial for reducing maintenance costs and improving the reliability of transformer. This study investigates Rh-doped TiO2(Rh-TiO2) primarily as a sensing material for these gases, with its strong adsorption capability serving as a key enhancing mechanism. Based on density functional theory (DFT) calculations, we established stable Rh-TiO2/gas configurations. Analysis of adsorption energy and band gap reveals that Rh-TiO2exhibits particularly strong adsorption for H2and C2H2, which translates into a promising and selective sensing response towards H2. Furthermore, density of states (DOS) analysis confirms the strong chemisorption mechanism involved. This strong interaction not only underpins the high sensitivity required for detection but also suggests a dual-function potential for gas scavenging. Consequently, this study provides a theoretical foundation for developing high-performance Rh-TiO2-based sensors to enhance power transformer monitoring.