• 文献标题:   Raman spectroscopy on hydrogenated graphene under high pressure
  • 文献类型:   Article
  • 作  者:   PAKORNCHOTE T, GEBALLE ZM, PINSOOK U, TAYCHATANAPAT T, BUSAYAPORN W, BOVORNRATANARAKS T, GONCHAROV AF
  • 作者关键词:   hydrogenated graphene, graphane, high pressure, thermodynamic pathway, raman spectroscopy
  • 出版物名称:   CARBON
  • ISSN:   0008-6223 EI 1873-3891
  • 通讯作者地址:   Chulalongkorn Univ
  • 被引频次:   6
  • DOI:   10.1016/j.carbon.2019.09.077
  • 出版年:   2020

▎ 摘  要

We applied laser-heating in diamond anvil cells (LHDAC) to synthesize a hydrogenated single-layer graphene (SLG) and to explore the pathway toward graphane (fully hydrogenated SLG). We employed Raman spectroscopy to investigate SLG on a Cu substrate that was compressed up to 8 GPa and 20 GPa with 2.2% and 4.6% compressive strain, respectively, followed by laser-heating. After laser-heating, G and 2D peaks exhibit a redshift, and then form a hysteresis loop during decompression. This phenomenon can be due to either of two mechanisms, or both; the formation of C-H chemical bonds in massive hydrogenated SLG, and a reduction of the frictional stress between SLG and Cu substrate causing a relaxation of SLG lattice toward its free-standing equilibrium structure. The correlation between G and 2D peaks also changes significantly after laser-heating at 8 GPa, resembling the correlation measured in hole-doping experiments. Finally, residual hydrogen remains bonded to the graphene layer after decompression to ambient pressure, and the amount of hydrogen increases as a function of pressure at which the sample was laser-heated. (C) 2019 Elsevier Ltd. All rights reserved.