• 文献标题:   First principles analysis of graphene and its ability to maintain long-ranged interaction with H2S
  • 文献类型:   Article
  • 作  者:   HEGDE VI, SHIRODKAR SN, TIT N, WAGHMARE UV, YAMANI ZH
  • 作者关键词:   electronic structure of graphene, impurity defect level, adsorption kinetic, desorption kinetic
  • 出版物名称:   SURFACE SCIENCE
  • ISSN:   0039-6028 EI 1879-2758
  • 通讯作者地址:   UAE Univ
  • 被引频次:   19
  • DOI:   10.1016/j.susc.2013.11.015
  • 出版年:   2014

▎ 摘  要

We determine the chemical activity of (a) carbon site of pristine graphene, (b) Stone-Wales (SW) defect site, and (c) BN-sites of BN-doped graphene towards adsorption of a toxic gas H2S, through comparative analysis based on first-principles density functional theoretical calculations incorporating van der Waals (vdW) interactions. While the adsorption of H2S is weak at both C and BN sites with a binding energy of 15 k J/mol, it is significantly stronger at the Stone-Wales defect site with a much higher binding energy of 26 k J/mol. This is clearly reflected in the contrasting orientation of H2S molecule in the relaxed geometries: the sulfur atom of H2S is closer to graphene (at a distance 3.14 angstrom) during physisorption at C and BN sites, while the molecule's H atoms come closer to graphene (at a distance 2.84 angstrom) during physisorption at the Stone-Wales defect site. The origin of the stronger binding interaction between H2S and a SW defect site is attributed to two possible reasons: (i) an increase in the vdW interaction; and (ii) the lowering of both energy of the HOMO level and the total energy of the H2S molecule in attaining a stable configuration. Our findings are compared to the available theoretical results and their technological relevance is further discussed. (C) 2013 Published by Elsevier B.V.