Detection of decomposed gases in SF6 surge arrester contaminated conditions in ultra-high voltage transmission lines based on Ta-doped defective h-BN nanosheet: A DFT study

SF6 surge arrester on ultra-high voltage transmission lines plays a critical role in the entire power transmission system. They not only protect electrical equipment from the dangers of high transient over voltages, but also bear the responsibility of maintaining the safety and stability of the transmission lines. Detecting the decomposed gases under polluted conditions inside SF6 surge arresters is of paramount importance. In this paper, based on extensive investigations and the application of density functional theory and 2D materials, we conducted a study on the detection of decomposed gases (HF, H2S, SOF2) in SF6 surge arresters for ultra-high voltage transmission lines under polluted conditions using Ta-doped defective h-BN nanosheets gas sensor. Revealing the adsorption and sensing mechanisms of these target gases on h-BN sensors through band structure, density of states, projected density of states, and differential charge density analysis. The results showed that Ta metal particle modification significantly improves the electronic activity of defective h-BN, substantially reducing the band gap values from 4.560 eV to 0.153 eV and 0.912 eV in the B atom and N atom defective oping systems. Meanwhile, Ta-doped defective h-BN exhibits strong selectivity and sensitivity to three decomposition components, with the adsorption capability ranking as SOF2 > H2S > HF, all of which are physical chemisorption types. Furthermore, in terms of various adsorption parameters, defective h-BN’s adsorption ability far surpasses other materials, offering broad prospects for practical applications. The results of this work contribute to the development and application of Ta-doped defective h-BN sensors for the detection of decomposed gases inside SF6 surge arresters under polluted conditions.