Gas sensing properties of <scp>Mg</scp>‐doped graphene for <scp>H<sub>2</sub>S</scp>, <scp>SO<sub>2</sub></scp>, <scp>SOF<sub>2</sub></scp>, and <scp>SO<sub>2</sub>F<sub>2</sub></scp> based on <scp>DFT</scp>
Peng Xiao, Dongsheng Liu, Feng Zhao, Chao Tang
Abstract
Abstract Sulfur hexafluoride decompositions have been studied to analyze their adsorption properties on pristine graphene (PG) and Mg‐doped graphene (MgG). First of all, after calculating the formation energy of three Mg doping sites, the T doping site of Mg‐doped graphene is the most stable one. Then, several characteristic structures with different orientations and positions of the gas molecules have been carried out to adsorb on PG and MgG, respectively. By calculating the adsorption energies and distance, the most stable adsorption structure of each gas molecule is obtained. In addition, transferred charge ( Q t ), the density of states (DOS), the energy of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were used to further analyze the conductivity change and chemical stability of each adsorption system. The results indicate that the adsorption interactions of H 2 S, SO 2 , SOF 2 , and SO 2 F 2 on PG are weak. H 2 S adsorbed on MgG presented physical adsorption, while the adsorption behaviors of SO 2 , SOF 2 , and SO 2 F 2 on MgG are chemisorption. And the adsorption strength was SO 2 F 2 > SOF 2 > SO 2 . In short, MgG shows better selectivity and higher sensitivity to SO 2 , SOF 2 , and SO 2 F 2 than PG, demonstrating that the MgG material can be used as suitable gas sensing equipment based on SF 6 decomposition products detection, which provides a meaningful guide of alkaline earth metal‐doped graphene in the detection of partial discharge and partial overheat in gas‐insulated switchgears (GIS).