Adsorption and gas sensitivity properties of graphene and Rh-decorated graphene towards SF6 decomposed gases: A DFT study.

In order to solve the serious threat of SF 6 decomposed gases (H 2 S, SO 2 , SOF 2 , SO 2 F 2) to the stable operation of electrical equipment. In this study, the geometric structure, adsorption energy, density of states (DOS), sensitivity based on band structure and recovery time of H 2 S, SO 2 , SOF 2 , SO 2 F 2 on graphene and Rh-modified graphene (Rh-graphene) were investigated computationally by density functional theory (DFT). The geometric structure of Rh-graphene was optimized with an average Rh-C bond length of 1.891 Å. According to the analysis of DOS and band structure, the electrical conductivity has a little effect of the Rh-graphene compared with pristine graphene, but Rh modification can regulate the band gap of graphene. The adsorption energy (E ad) and the sensitivity (S) at work temperature indicate that graphene has ideal adsorption and sensing properties for SO 2 and Rh-graphene reflects the excellent applicability as the SO 2 and SO 2 F 2 gases sensor with the sensitivity of approximately −99 % and −60 %, respectively. The Graphene/SO 2 system owns the minimum recovery time of 2154.3 ps. The recovery time of Rh-graphene/H 2 S and SOF 2 is several orders of magnitude smaller than Rh-graphene/SO 2 and SO 2 F 2. The analysis of DOS and band structure was used to explain the sensing mechanism. The study would lay a theoretical foundation for the development of SF 6 decomposed gases sensor for electrical equipment insulation. [Display omitted] • Adsorption, sensitivity, recovery time and electronic behavior of SF 6 decomposed gases on graphene and Rh-modified graphene were investigated systematically. • The adsorption energy and the sensitivity indicate that graphene has ideal adsorption and sensing properties for SO 2 and Rh-graphene reflects the excellent applicability as the SO 2 and SO 2 F 2 gases sensor. • The analysis of density of state (DOS) and band structure illustrates the sensing mechanism and further prove the applicability of graphene and Rh-graphene for SF 6 decomposed gases. [ABSTRACT FROM AUTHOR]