Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (10): 2022-2028.doi: 10.3866/PKU.WHXB201705174

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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)

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