Research on high-performance materials for adsorption and monitoring of SF6 and its decomposed gases: First principle DFT calculations

Abstract

High-voltage gas-insulated switchgear (GIS) experiences insulation aging and related issues during prolonged operation, which significantly reduces the stability and safety of energy power equipment. Therefore, real-time monitoring and assessment of the insulation condition of these devices is essential. This study, based on first-principles calculations, reveals the gas-sensitive properties of decomposition gases of SF₆ and its five insulation defects on the surfaces of AlN and Pt₂–AlN at the quantum level by calculating the electronic density (total electronic density, differential electronic density, and spin density), density of states (total and partial density of states), and the Integrated Crystal Orbital Hamilton Population (ICOHP). Notably, the modification of the Pt₂ cluster significantly enhances the electronic properties of AlN, improving the overall conductivity of the system. Furthermore, the adsorption properties of the p-type semiconductor Pt₂-ALN for H₂S are improved, and calculations of the work function, band gap, and its rate of change indicate that the doped structure possesses the potential to be used as a sensor. Additionally, we explored the feasibility of AlN (targeting SO₂) and Pt₂–AlN (targeting H₂S) as insulation defect warning materials under different environmental conditions. The results of the sensor application calculations demonstrate that AlN possesses the capability for SO₂ purification and can function as a disposable embedded sensor array, while Pt₂–AlN shows promise as a sustainable sensor material for H₂S monitoring at room temperature (300 K), with a desorption time of 0.46 s. Our research aims to provide new insights into semiconductor sensor monitoring of SF₆ gas-insulated equipment and offers guidance for the development of novel materials and sensor devices.