DFT study on the selective adsorption properties of modified graphene for SF6 decompositions
Xin Gao, Qu Zhou, Jingxuan Wang, Lingna Xu, Wen Zeng
Abstract
In the paper, the adsorption of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S on three modified graphene by doping Pd atom and introducing oxygen-containing functional groups (Pd-G, G-O and G-OH) was studied based on first principles. All the three modification methods improve the adsorption performance of graphene for H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S, among which the introduction of hydroxyl shows the best with the adsorption energy of -1.255eV. Nevertheless, Pd-G, G-O and G-OH exhibited similar adsorption properties for SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , SOF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S, with the small difference of adsorption energy values. So the three modified graphene structures show poor selective adsorption performance for H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S. Then, the influence of the combine interaction of Pd atom and oxygen-containing functional group on the performance of graphene (Pd-G-O, Pd-G-OH) adsorbing H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S is further studied. Among them, the structure of Pd-G-O is stable, and the adsorption energy of Pd-G-O adsorbing H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S is -1.623eV. However, the adsorption energies of SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , SO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and SOF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> adsorbed on Pd-G-OH are -0.751eV, -0.799eV and -0.552eV, respectively. The excellent adsorption capacity of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S on Pd-G-O is verified from the practical feasibility and selectivity. Therefore, Pd-G-O is a potential gas sensor material for selective adsorption of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> S.