Confined growth of pyridinic N–Mo2C sites on MXenes for hydrogen evolution

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 8; no. 15; pp. 7109 - 7116
• Main Authors: Wang, Hao, Lin, Yanping, Liu, Shuyuan, Li, Jianmin, Bu, Liangmin, Chen, Jianmei, Xu, Xiao, Jin-Ho, Choi, Gao, Lijun, Jong-Min, Lee
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 01.01.2020
• Subjects: Acidic oxides; active sites; annealing; Carbon; catalysts; Charge transfer; Dopamine; Electrocatalysts; electrochemistry; Electrolysis; encapsulation; Hydrogen; Hydrogen evolution reactions; Hydrogen production; ions; molybdenum; MXenes; nanotechnology; Nitrogen; Oxidation; Polymerization
• ISSN: 2050-7488; 2050-7496; 2050-7496
• DOI: 10.1039/d0ta01697g

Developing low-cost and high-performance hydrogen evolution reaction (HER) electrocatalysts is a key research area for scalable hydrogen production from water electrolysis. Here, a hybrid of nitrogen-doped carbon encapsulated Mo2C nanodots on Ti3C2Tx MXene (Mo2C/Ti3C2Tx@NC) is developed through in situ polymerization of dopamine and a Mo precursor on the Ti3C2Tx MXene surface. During the annealing treatment, the polydopamine plays multiple roles in forming N-doped carbon, confining MoO42− ions into ultrasmall Mo2C nanodots, and stabilizing the MXene flakes against spontaneous oxidation. The as-synthesized hybrid exhibits excellent HER activity in acidic electrolyte with an overpotential of 53 mV at 10 mA cm−2 and excellent stability over 30 hours. The combination of experiments and simulations demonstrates that pyridinic N-doped carbon coated Mo2C nanodots serve as the active sites and Ti3C2Tx MXene facilitates the charge transfer, synergistically contributing to the superior HER performance.