Zhang Mingjun, Deng Ke, Wei Fei, Wu Xiaoling, Du Lin, Liu Wei
Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800, China.
University of Chinese Academy of Science, Beijing 100049, China.
ACS Omega. 2021 Dec 23;7(1):752-760. doi: 10.1021/acsomega.1c05395. eCollection 2022 Jan 11.
The interaction between graphene-based materials and hydrogen isotopes is of great importance with respect to the adsorption of hydrogen in graphene and the removal of tritium from irradiated nuclear graphite. In the present study, based on density functional theory, we investigate and discuss the adsorption and molecular desorption of hydrogen isotopes on the edges and stable interior defects. The adsorption energy of one hydrogen on graphene-based materials is between -2.0 and -5.0 eV, which is related to the structure and hydrogenation level. The hydrogenation level increases with the hydrogen partial pressure and decreases with the temperature. The best adsorption pathways of hydrogen isotopes in graphene-based materials are determined, together with three different desorption stages with different activation energies. The desorption peaks of thermal desorption spectrometry agree well with stage 2 and stage 3 of simulation. Our results can provide a theoretical basis for the study of the hydrogen isotope behaviors in graphene and the decontamination of nuclear graphite.
基于石墨烯的材料与氢同位素之间的相互作用对于氢在石墨烯中的吸附以及从辐照核石墨中去除氚而言至关重要。在本研究中，基于密度泛函理论，我们研究并讨论了氢同位素在边缘和稳定内部缺陷上的吸附及分子解吸。一个氢在基于石墨烯的材料上的吸附能在-2.0至-5.0电子伏特之间，这与结构和氢化水平有关。氢化水平随氢分压升高而增加，随温度降低而降低。确定了基于石墨烯的材料中氢同位素的最佳吸附路径，以及具有不同活化能的三个不同解吸阶段。热解吸光谱的解吸峰与模拟的第二阶段和第三阶段吻合良好。我们的结果可为研究石墨烯中氢同位素行为及核石墨去污提供理论依据。
