A First-Principles Study on Hydrogen Sensing Properties of Pristine and Mo-Doped Graphene

Abstract

The adsorption of H2 on the pristine and Mo-doped graphene was investigated by density functional theory (DFT) calculations. The structural and electronic properties of H2-graphene systems were studied to understand the interaction between H2 molecule and graphene-based material. Our calculation results showed the pristine graphene was not an ideal sensing material to detect H2 molecule as it ran far away from the pristine graphene surface. Different with pristine graphene, the Mo-doped graphene presented much higher affinities to the H2 molecule. It was found that the placed H2 molecules could stably be chemisorbed on the Mo-doped graphene with high binding energy. The electronic property of Mo-doped graphene was significantly affected by the strong interaction and orbital hybridization between H2 and Mo-doped graphene sheet. The H2 molecule would capture more charges from the doped graphene than the pristine system, indicating the higher sensitivity for the graphene doped with Mo.

Enhanced hydrogen storage performance of graphene nanoflakes doped with Cr atoms: a DFT study

“…44 Similar results were also found in the Mo-doped or Pd-doped graphene sheets. 24,45 In the following research, the hydrogen molecules with different orientations were placed on the built nanoakes to investigate the interactions between the hydrogen gas and the PGNF (or CrGNF). Two typical adsorption modes were constructed for one hydrogen molecule adsorbed on PGNF (or CrGNF): (i) the hydrogen molecule was parallel to the nanoake with H atom above the active site (C atom for PGNF or Cr atom for CrGNF); (ii) the hydrogen molecule was perpendicular to the nanoake with the H atom above the active site.…”

“…9,22,23 The theoretical and experimental studies of Yang et al showed that the hydrogen storage capacity of the microporous carbon-based material could be signicantly enhanced by modied with Ru due to the spillover effect. 24 Fan and his workmates have also done a rst-principles study on the hydrogen storage properties of the Sc-decorated graphene. They found that there were six H 2 molecules in maximum adsorbed on the modied Sc atom.…”

Role of defects in carbon materials during metal-free formic acid dehydrogenation

“…In accordance with previous studies, pristine graphene has an inactive π-conjugation, which is not sensitive in the adsorption of molecules. [71][72][73] In fact, the pristine graphene is not capable to chemically bind molecular formic acid on its surface. Another possible way to adsorb FA is through a dissociative adsorption (DA),…”

Selective decomposition of hydrazine over metal free carbonaceous materials

“…In line with previous studies, the graphitic areas possess an inactive p-conjugation, not sensitive to adsorption of molecules. 64,[90][91][92] Only single vacancies showed a favourable (exothermic) interaction with ammonia, indicating that a r( r BCP ) smaller than 0.6 e À A À3 defines the active sites on carbon surfaces. Combining the Laplacian of charge density analysis and the performed tests with NH 3 , we were able to identify C 3 , C 3 0 and C 7 in the single vacancy system as possible active sites (Fig.…”