Gas-sensing properties of Ti, Zr, V, and Nb-modified Ti3C2O2 for decomposed gases in locomotive electric transformers: a DFT study

Abstract

This study investigated the adsorption properties of the decomposed gases in locomotive electric transformers: C₂H₂, CH₄, and CO on metal atoms (Ti, Zr, V, and Nb) modified Ti₃C₂O₂ by DFT calculations. The optimal modification structures of metal atoms on Ti₃C₂O₂ were calculated and band structure, adsorption energy, charge transfer, density of states, charge density diagrams, and recovery time were used to analyze the adsorption properties. The results showed that metal atom modifications could enhance the conductivity and surface activity. In the adsorption systems, gas received electrons, and the conductivity was changed after gas adsorption. The adsorption processes of CH₄ on modified systems were physical and had an extremely short recovery time. However, new bonds were formed in the adsorption of C₂H₂ and CO resulting in long recovery times. In essence, Ti, Zr, V, and Nb-doped Ti₃C₂O₂ can be used as gas-sensing materials for CH₄ and as adsorbents for C₂H₂ and CO gases in locomotive electric transformers.