First-principles DFT study for the structural stability of Hydrogen passivated graphene (H-graphene) and atomic adsorption of oxygen on H-graphene with different schemes

TL;DR

This study uses first-principles DFT calculations to analyze the structural stability, electronic properties, and oxygen adsorption behavior of hydrogen passivated graphene clusters with various shapes and adsorption schemes.

Contribution

It provides new insights into the stability differences between rectangular and circular H-graphene clusters and systematically investigates oxygen adsorption schemes on these clusters.

Findings

Rectangular clusters are 1.5% more stable than circular ones.

HOMO-LUMO gap varies significantly between shapes, 2.159 eV vs. 0.346 eV.

Oxygen adsorption behavior depends on the scheme and cluster shape.

Abstract

First-principles DFT levels of calculations have been carried out in order to study the structural stability and electronic properties of hydrogen passivated graphene (H-graphene) clusters. Two different shaped clusters, rectangular and circular, consisting of 6 to 160 carbon atoms and hydrogen termination at the zigzag boundary edges have been studied. The relative stability of rectangular shaped cluster consisting 96 C-atoms found to be 1.5% greater than that of circular shape cluster consisting same number of C-atoms. In comparing circular and rectangular cluster containing same number of C-atoms, the HOMO-LUMO gap of former have been predicted to be 2.159 eV and that of later just 0.346 eV. Adsorption of oxygen atom on H-graphene with different schemes including single sided, both sided and high concentration adsorption, was also studied systematically through first-principles DFT calculations by taking four different H-graphene clusters.