物理化学学报 >> 2014, Vol. 30 >> Issue (10): 1821-1826.doi: 10.3866/PKU.WHXB201408192

理论与计算化学 上一篇    下一篇

二维TiC 层表面H2的化学吸附与物理吸附

杨建辉1, 计嘉琳2, 李林1, 韦世豪3   

  1. 1. 衢州学院教师教育学院, 浙江衢州 324000;
    2. 衢州学院化学与材料工程学院, 浙江衢州 324000;
    3. 宁波大学理学院微电子科学与工程系, 浙江宁波 315211
  • 收稿日期:2014-05-26 修回日期:2014-08-15 发布日期:2014-09-30
  • 通讯作者: 杨建辉 E-mail:jianhuiyoung@gmail.com
  • 基金资助:

    国家自然科学基金(11347138)和衢州学院人才基金(BSYJ201311)资助项目

Hydrogen Chemisorption and Physisorption on the Two-Dimensional TiC Sheet Surface

YANG Jian-Hui1, JI Jia-Lin2, LI Lin1, WEI Shi-Hao3   

  1. 1. College of Teacher Education, Quzhou University, Quzhou 324000, Zhejiang Province, P. R. China;
    2. College of Chemical and Material Engineering, Quzhou University, Quzhou 324000, Zhejiang Province, P. R. China;
    3. Department of Microelectronic Science and Engineering, Faculty of Science, Ningbo University, Ningbo 315211, Zhejiang Province, P. R. China
  • Received:2014-05-26 Revised:2014-08-15 Published:2014-09-30
  • Contact: YANG Jian-Hui E-mail:jianhuiyoung@gmail.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11347138) and Talent Training Funds of Quzhou University, China (BSYJ201311).

摘要:

第一性原理计算研究发现由于二维TiC 单原子层具有高的比表面积与大量的暴露在表面的Ti 原子,其是一种非常有潜力的储氢材料. 计算结果显示H2可以在二维TiC 单原子层表面进行物理吸附与化学吸附. 其中化学吸附能为每个氢分子0.36 eV,物理吸附能是每个氢分子0.09 eV. 覆盖度为1和1/4层(ML)时,H2分子在二维TiC 单原子层表面的离解势垒分别为1.12 和0.33 eV. 因此,除了物理吸附与化学吸附,TiC 表面还存在H单原子吸附. 最大的H2储存率可以达到7.69%(质量分数). 其中,离解的H原子、化学吸附的H2、物理吸附的H2的储存率分别为1.54%、3.07%、3.07%. 符合Kubas吸附特征的储存率为3.07%. 化学吸附能随覆盖度的变化非常小,这有利于H2分子的吸附与释放.

关键词: 储氢, 第一性原理, 过渡金属化合物, 二维材料, 碳化物

Abstract:

The TiC monolayer sheet, a new two-dimensional structure, is proposed as a promising hydrogen storage material because of its high specific surface area and the large number of exposed Ti ions on the surface. First principles calculations showed that both chemisorption and physisorption of H2 can take place on the TiC sheet surface, with adsorption energies of 0.36 and 0.09 eV per H2, respectively. For 1 and 1/4 monolayer (ML) coverages, the dissociation barriers of H2 on the TiC sheet surface were calculated to be 1.12 and 0.33 eV, respectively. Thus, as well as physisorption and chemisorption, there were dissociated H atoms on the TiC sheet surface. The maximum H2 storage capacity was calculated to be up to 7.69% (mass fraction). The capacities were 1.54%, 3.07%, and 3.07% for dissociated H atoms, and chemisorption and physisorption of H2, respectively. Considering only Kubas adsorption, the hydrogen storage capacity was 3.07%. The adsorption energy for H2 chemisorption on the TiC sheet surface only slightly changed at different coverages, which benefits the storage and release of H2.

Key words: Hydrogen storage, First principles, Transition metal compound, Two-dimensional material, Carbide

MSC2000: 

  • O647