Different doping of penta-graphene as adsorbent and gas sensing material for scavenging and detecting SF6 decomposed species

Abstract

The first-principle study using density functional theory (DFT) was adopted to investigate the adsorption of five types of SF6 decomposed products (SO2, SOF2, SO2F2, H2S and HF) over the pristine and B/N doped penta-graphene (PG). The adsorption structures with adsorption energy, electron transfer, band structure, density of states (DOS) were detailed discussed. The sensing properties were also estimated based on the band structure, electron transfer and adsorption energy. The results show that the pristine PG shows small adsorption energy to every molecule of SF6 decomposed products but after doping of B or N atom, the adsorption energy and electron transfer experience different degrees of improvement for different adsorption. The conduction of pristine PG may decrease after adsorbing SO2 or H2S but the detection limit may be high. However, B-PG shows strong chemical interactions with SO2, HF and SO2F2 and can be promising adsorbent for these species at room temperature while can be used as gas sensing materials for SO2F2 and H2S at higher temperature. The N-PG only have strong chemical interactions to H2S and is a promising adsorbent and gas sensing materials for it. The conduction change of doped PG as sensing material can be estimated based on the electron transfer. The introduction of Si substrate will not obviously change the general trend of adsorption energy and electron transfer comparing to the adsorption not considering the substrate. The study can promote new sensing materials development for detecting and scavenging impurities in SF6 based electrical equipment to ensure the stability and sustainability of the whole power system which is important for people's lives.