• 文献标题:   Methodology and results of studying the states of hydrogen in graphene structures
  • 文献类型:   Article
  • 作  者:   NECHAEV YS, CHERETAEVA AO, KOSTIKOVA EK, SHURYGINA NA, DENISOV EA, DAVYDOV SY
  • 作者关键词:   hydrogenated few 1 4 layer epitaxial graphene, diamondlike structures as in graphane, analysis of hydrogen thermal desorption data, activation energie, frequency factor
  • 出版物名称:   FULLERENES NANOTUBES CARBON NANOSTRUCTURES
  • ISSN:   1536-383X EI 1536-4046
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1080/1536383X.2021.1984900 EA SEP 2021
  • 出版年:   2022

▎ 摘  要

In this work, an effective methodology of analysis of thermal desorption spectra (TDS) of hydrogen in carbon materials was further developed and applied. The methodology makes it possible, from TDS data of one heating rate, to determine the activation energies and pre-exponential factors of the rate constants of desorption processes. The TDS data of Rajasekaran et al. for hydrogenated epitaxial graphenes with a diamond-like structure (as in graphane) were analyzed. Some new information was obtained about the states of hydrogen in such unusual structures. It was shown that about half of the hydrogen contained in the samples is localized in the interfacial regions (between graphene and the substrate), while the desorption of such hydrogen is limited by diffusion (with three activation energies (34 kJ/mol(H-2), 45 kJ/mol(H-2), and 68 kJ/mol(H-2)) of hydrogen molecules in these regions to the lateral surfaces of the samples. It was also shown that the rest of the hydrogen is localized on the top surface of the samples, while desorption of hydrogen atoms occurs with two activation energies and frequency factors (174 kJ/mol(H), 2 x 10(13) s(-1), and 256 kJ/mol(H), 3 x 10(18) s(-1)); the obtained quantities are comparable to the related characteristics for graphane.