A universal pH range and a highly efficient Mo2C-based electrocatalyst for the hydrogen evolution reaction

Huang, Jiajia, Wang, Jingyi, Xie, Ruikuan , Tian, Zhihong, Chai, Guoliang, Zhang, Yanwu, Lai, Feili, He, Guanjie, Liu, Chuntai, Liu, Tianxi, Shearing, Paul R. and Brett, Dan J. L. (2020) A universal pH range and a highly efficient Mo2C-based electrocatalyst for the hydrogen evolution reaction. Journal of Materials Chemistry A, 8 (38). pp. 19879-19886. ISSN 2050-7488

Full content URL: https://doi.org/10.1039/D0TA07091B

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A universal pH range and a highly efficient Mo2C-based electrocatalyst for the hydrogen evolution reaction
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Abstract

Electrochemical water splitting is a promising approach to generate ‘green’ hydrogen. The efficiency of this process relies on the effectiveness of the electrocatalysts used. The electro-kinetics of the hydrogen evolution reaction (HER) is highly pH dependent and conventional catalysts typically are expensive and rare platinum-based materials. The development of low-cost, multi-component electrocatalysts, where each of the components has a synergistic effect, can be an effective approach to improve kinetics. Herein, a series of transition metal (Fe, Mn, Co, and Ni)-modified molybdenum carbides in a nitrogen-doped carbon matrix (TM-Mo2C@NCF) are synthesised to maximise exposed active sites. Among them, Fe-Mo2C@NCF delivers the best-in-class HER performance over a wide range of electrolytes. Tafel slopes of 76, 109 and 110 mV dec−1 and overpotentials of 65, 130 and 129 mV at 10 mA cm−2 were obtained in 1.0 M KOH, 1.0 M phosphate buffer solution (PBS) and 0.5 M H2SO4, respectively. The computational study further indicates that the synergistic electronic modulation co-activated by Fe and N dopants in Fe-Mo2C@NCF can reduce the Gibbs free energy of H adsorption (ΔGH*) and render the Mo–Mo bridge site the most energetically favorable adsorption site for the H* intermediate, which contributes to an increased HER performance.

Subjects:F Physical Sciences > F200 Materials Science
F Physical Sciences > F161 Organometallic Chemistry
F Physical Sciences > F100 Chemistry
Divisions:College of Science > School of Chemistry
ID Code:43121
Deposited On:25 Nov 2020 13:56

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