• 文献标题:   H2S adsorption on graphene in the presence of sulfur: A density functional theory study
  • 文献类型:   Article
  • 作  者:   FAYE O, RAJ A, MITTAL V, BEYE AC
  • 作者关键词:   h2s, adsorption, graphene, dft, singlevacancy defect
  • 出版物名称:   COMPUTATIONAL MATERIALS SCIENCE
  • ISSN:   0927-0256 EI 1879-0801
  • 通讯作者地址:   Petr Inst
  • 被引频次:   17
  • DOI:   10.1016/j.commatsci.2016.01.034
  • 出版年:   2016

▎ 摘  要

The high affinity of graphene for H2S makes it a potential adsorbent for separating H2S from industrial waste gas streams, and for its use in H2S sensors. The gas streams containing H2S also contain S atoms that can get bonded to graphene during adsorption. Moreover, at high temperatures, H2S dissociate at graphene defects leading to H-2 desorption with S atom remaining on graphene. This study reports the effect of the presence of S atom on graphene on H2S adsorption using plane-wave density functional theory to assess the suitability of graphene-based adsorbents for continuous H2S capture. During H2S interaction with pristine graphene with S atom bonded to it, a surface cleaning mechanism was observed, where H2S exothermically removed S atom by forming H2S2. When S atom was doped in the single-vacancy defect of graphene, both physisorption and chemisorption of H2S was observed. The adsorption energy released during H2S physisorption on S-doped graphene was comparable to that for pristine graphene. However, during chemisorption, H2S dissociated on S-doped graphene to form HSSH bonded to graphene with the release of a high amount of energy. The results suggest that S atom in single-vacancy defects can enhance H2S capture on graphene. (C) 2016 Elsevier B.V. All rights reserved.