The interactions of nitrogen dioxide with graphene-stabilized Rh clusters: a DFT study

Abstract

We study the interactions of NO2 gas molecules with Rh nanoparticles supported on graphene, using first-principles molecular dynamics in the Car-Parrinello scheme. The stability, morphology, adsorption energies of various models of Rhx nanoparticles (x = 1, 3, 10, 20) supported on graphene, and the binding of NO2 molecules to the Rh clusters, together with its effect on the graphene properties, are reported. Metastable flat structures anchored to the substrate that can bind NO2 to Rh via both N and O atoms are identified, with adsorption energies in the range 60-70 kcal per mole per molecule.

Rhodium Nanosheets–Reduced Graphene Oxide Hybrids: A Highly Active Platinum-Alternative Electrocatalyst for the Methanol Oxidation Reaction in Alkaline Media

“…This indicates that PEI is a stabilizing agent that stops the aggregation of Rh nanoparticles and a facet-selective agent that induces the generation of Rh nanosheets during the synthesis of the Rh-NSs/RGO hybrids. It is evident that PEI adsorbs mainly on Rh(111) facets due to the strong interaction of amine–Rh, which contributes to the generation of the Rh-NSs according to the confined growth mechanism. ,,− Besides, the single-component Rh-NPs without RGO only contain a small amount of Rh nanosheets (Figure B). This fact indicates that the existence of the GO facilitates the formation of the Rh nanosheets during the synthesis of the Rh-NPs/RGO hybrids.…”

Hierarchical Self-Assembly of Noncanonical Guanine Nucleobases on Graphene

“…On the other hand, the electrostatic energy decreases with an increase in the surface coverage (Figure S7c), suggesting an enhanced intermolecular H-bonded interaction and a net weakening of the electrostatic interactions between the G n bases at a high surface coverage. The base–base stacking interaction energy and the base–substrate interaction energy have been investigated at the level of DFT ,, and ab initio MD simulation . At the level of dispersion-corrected DFT, we have discussed that in the presence of explicit waters base–base stacking is energetically favored over the aligned configuration, with more water molecules solvating the bases with the formation of water hydration spheres in the former configuration.…”

“…The base−base stacking interaction energy and the base−substrate interaction energy have been investigated at the level of DFT 42,43,38 and ab initio MD simulation. 44 At the level of dispersion-corrected DFT, 38 we have discussed that in the presence of explicit waters base− base stacking is energetically favored over the aligned configuration, with more water molecules solvating the bases with the formation of water hydration spheres in the former configuration. This implied that graphene helps to disperse the guanine bases and favors the monolayer-aligned configuration over the stacked mode of adsorption.…”

On the mechanism of gas adsorption for pristine, defective and functionalized graphene

“…A comprehensive and deep understanding of NO 2 gas adsorption on defected and functionalized graphene can be useful in development of practical graphene-based gas sensors. Previous reports suggest that NO 2 gas adsorption can be enhanced through modifying graphene structure via creation of vacancies 21,22 , doping impurities [22][23][24][25][26] and attaching chemical functional groups [27][28][29][30] . Using density functional theory (DFT), Lee et al elucidated that the monovacant graphene have strong NO 2 gas adsorption 21 and Zhou et al proposed that doping of transitional metal atoms (Cu, Ag and Au) can improve the sensing performance of graphene 23 .…”