Work

Selective detection of dissolved fault gases in on-load tap changer insulating oil using WO3−-Modified Janus HfSeTe: A First-Principles Study

Year: 2026

Type: article

Abstract: Online monitoring of dissolved fault gases in on-load tap changer (OLTC) insulating oil is crucial for the reliable operation and condition assessment of power equipment. In this work, first-principles calculations were employed to systematically investigate the gas-sensing behavior of pristine Janus HfSeTe monolayers and WO3-modified HfSeTe toward typical dissolved fault gases, including H2, CO2, CH4, C2H4, and C2H2. The results show that pristine HfSeTe, irrespective of Se- or Te-terminated surfaces, exhibits weak physical adsorption for all investigated gases, accompanied by negligible charge transfer and minor electronic structure modulation, indicating limited intrinsic sensing capability. In contrast, WO3 functionalization significantly enhances gas–substrate interactions and induces pronounced electronic responses toward unsaturated hydrocarbons. WO3–HfSeTe displays strong and selective adsorption for C2H4 and C2H2, while remaining insensitive to H2, CO2, and CH4. Notably, C2H4 adsorption results in a substantial band gap reduction of 32.49%, whereas C2H2 adsorption is characterized by considerable charge transfer and deep electronic state reconstruction. Desorption kinetic analysis reveals that WO3–HfSeTe enables room-temperature operation for C2H4 with a moderate desorption time of 69.8 s, and rapid recovery for C2H2 can be achieved under mild thermal activation. Ab initio molecular dynamics (AIMD) simulations further confirm the thermal stability of the adsorption systems. These findings highlight the potential of WO3-modified Janus HfSeTe for selective online monitoring of key dissolved fault gases in OLTC insulating oil.

Source: Surfaces and Interfaces

DOI: 10.1016/j.surfin.2026.108662

Authors: Linze Li, Ziwen Huang, Hongyu Xu, Wen Zeng, Qu Zhou

Institutions: Southwest University, Chongqing University

Language: English

Topic: Gas Sensing Nanomaterials and Sensors

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $2,670