• 文献标题:   Relevance of the Nuclear Quantum Effects on the Proton/Deuteron Transmission through Hexagonal Boron Nitride and Graphene Monolayers
  • 文献类型:   Article
  • 作  者:   EKANAYAKE NT, HUANG JS, JAKOWSKI J, SUMPTER BG, GARASHCHUK S
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICAL CHEMISTRY C
  • ISSN:   1932-7447
  • 通讯作者地址:   Univ South Carolina
  • 被引频次:   6
  • DOI:   10.1021/acs.jpcc.7b08152
  • 出版年:   2017

▎ 摘  要

According to recent experiments, atomically thin hexagonal boron nitride and graphene are permeable to protons and deuterons (and not to other atomic species), and the experimental estimates of the activation energy are lower than the theoretical values by about 0.5 eV for the isolated protonmembrane transfer model. Our analysis of the electronic potential energy surfaces along the normal to the transmission direction, obtained using correlated electronic structure methods, suggests that the aqueous environment is essential to stabilize the proton transmission, as opposed to the hydrogen atom. Therefore, the process is examined within a molecular model of H2OH(D)(+)-material-H2O. Exact quantum-mechanical scattering calculations are performed to assess the relevance of the nuclear quantum effects, such as tunneling factors and the kinetic isotope effect (KIE). Deuteration is found to affect the thermal reaction rate constants (KIE of 3-4 for hexagonal boron nitride and 20-30 for the graphene) and to effectively lower the barriers to the proton transfer by 0.2 and 0.4 eV for the two membranes, respectively. This lowering effect is reduced for the deuteron by approximately a factor of 3. A more comprehensive description of the proton transmission is likely to require an extended explicit aqueous environment.