物理化学学报 >> 2017, Vol. 33 >> Issue (10): 2022-2028.doi: 10.3866/PKU.WHXB201705174

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二维M2XO2-2x(OH)2x(M=Ti, V;X=C, N)析氢催化活性的第一性原理研究

张绍政1,刘佳2,谢燕2,陆银稷2,李林1,吕亮2,杨建辉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 宁波大学微电子科学与工程系,浙江宁波315211
  • 收稿日期:2017-04-07 发布日期:2017-07-17
  • 通讯作者: 杨建辉 E-mail:jianhuiyoung@gmail.com
  • 基金资助:
    国家自然科学基金(51502154);国家自然科学基金(21271116);国家自然科学基金(21476127);国家自然科学基金(u1607119);衢州学院青年学术骨干培养计划(XNZQN201517)

First-Principle Study of Hydrogen Evolution Activity for Two-dimensional M2XO2-2x(OH)2x (M=Ti, V; X=C, N)

Shao-Zheng ZHANG1,Jia LIU2,Yan XIE2,Yin-Ji LU2,Lin LI1,Liang LÜ2,Jian-Hui YANG1,*(),Shi-Hao WEI3   

  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, Ningbo University, Ningbo 315211, Zhejiang Province, P. R. China
  • Received:2017-04-07 Published:2017-07-17
  • Contact: Jian-Hui YANG E-mail:jianhuiyoung@gmail.com
  • Supported by:
    the National Natural Science Foundation of China(51502154);the National Natural Science Foundation of China(21271116);the National Natural Science Foundation of China(21476127);the National Natural Science Foundation of China(u1607119);the Young Academic Leading Training Plan, Quzhou University, China(XNZQN201517)

摘要:

MXene是一种新型的二维析氢催化材料,其表面容易被亲水基团O和OH混合覆盖。我们基于第一性原理计算的方法,研究了M2XO2-2x(OH)2x(M=Ti,V;X=C,N)的析氢催化活性。计算结果显示,M2XO2-2x(OH)2x的析氢催化活性与其表面OH覆盖率(x)密切相关。对Ti2CO2-2x(OH)2x来说,OH覆盖率不超过1/3时,具有优异的析氢催化活性。对Ti2NO2-2x(OH)2x、V2CO2-2x(OH)2x和V2NO2-2x(OH)2x来说,OH覆盖率分别达到4/9、1/3和5/9时,才具有最佳的析氢催化活性。接着,电荷分析显示OH覆盖率会显著影响M2XO2-2x(OH)2x活性位点O基团的电荷量。最后,我们从态密度的角度揭示了析氢催化活性变化的原因,即活性位点O基团的氧化性随OH覆盖率的增大而被削弱。因此,本文提出了调节表面OH覆盖率来获取M2XO2-2x(OH)2x最佳析氢催化活性状态的方法,这在工业制氢生产过程中具有重要的应用价值。

关键词: 二维材料, MXene, 第一性原理, 析氢催化, 吸附

Abstract:

MXene is a new group of electrocatalysts for two-dimensional hydrogen evolution reaction (HER). Its surfaces are often covered by hydrophilic O and OH mixed groups. To find the effect of the O and OH mixed groups on HER, we studied the HER activity for M2XO2-2x(OH)2x (M=Ti, V; X=C, N) by first-principle calculations. Results indicate that HER activity is closely related to OH-occupied coverage (x). For Ti2CO2-2x(OH)2x, excellent HER activity could be maintained when the OH-occupied coverage was not larger than 1/3. For Ti2NO2-2x(OH)2x, V2CO2-2x(OH)2x, and V2NO2-2x(OH)2x, high HER activity was obtained when OH-occupied coverage reached 4/9, 1/3, and 5/9, respectively. Next, we analyzed the charge-transfer density and found that the charges on the oxygen groups were strongly affected by the OH-occupied coverage. Finally, we revealed the variation of HER activity that oxidizability of O groups is weakened with increasing OH-occupied coverage. In this paper, we propose a new method to obtain the optimal HER activity for M2XO2-2x(OH)2x by adjusting the OH-occupied coverage of the surfaces, which is useful in industrial hydrogen production.

Key words: Two-dimensional material, MXene, First-principle method, Hydrogen evolution reaction, Adsorption

MSC2000: 

  • O643