NTiO2 cluster (n = 3) modified GaNNT: A potential candidate for online monitoring for oil-immersed transformers

Abstract

The detection of the insulation state of electrical equipment, particularly oil-immersed transformers, requires continuous monitoring of dissolved gases in oil. Using Perdew-Burke-Ernzerhof (PBE) functional within the generalized gradient approximation (GGA), the adsorption properties of nTiO2 cluster (n = 3)-doped nanomaterial is studied based on density functional theory (DFT) to explore its applicability in gas sensing. In this work, nTiO2 (n = 3) is first proposed to investigate the adsorption properties of dissolved gases in oils (CH4, H2, and C2H2). The most stable structure’s binding energy (Eb) is −11.833 eV. The adsorption energy (Ea), sensitivity, and electrical behavior of CH4, C2H2, and H2 are also investigated with the findings revealing that C2H2 has superior adsorption and sensing properties than CH4 and H2, yet nTiO2 (n = 3)-GaNNT has the maximum sensitivity (5.21 × 106) to CH4 at room temperature. Moreover, the analysis of density of states (DOS), partial density of states (PDOS), energy band structure, and LUMO-HOMO indicate the suitability of nTiO2 (n = 3)-GaNNT for dissolved gases in oil. It's worth noting that the kind of physical adsorption makes it possible to realize desorption as a gas sensor. The results reveals that nTiO2 (n = 3)-GaNNT as a sensitive material is critical for online fault monitoring of dissolved gases in oil of oil-immersed transformers.