Synergistic Effect of Dual-Doped Carbon on Mo2C Nanocrystals Facilitates Alkaline Hydrogen Evolution

Min Zhou; Xiaoli Jiang; Weijie Kong; Hangfei Li; Fei Lu; Xin Zhou; Yagang Zhang

doi:10.1007/s40820-023-01135-0

Synergistic Effect of Dual-Doped Carbon on Mo₂C Nanocrystals Facilitates Alkaline Hydrogen Evolution

Nanomicro Lett. 2023 Jul 3;15(1):166. doi: 10.1007/s40820-023-01135-0.

Authors

Min Zhou^{1

2}, Xiaoli Jiang^{3

4}, Weijie Kong⁵, Hangfei Li⁵, Fei Lu⁵, Xin Zhou⁶, Yagang Zhang^{7

8}

Affiliations

¹ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, 611731, People's Republic of China. minzhou@yzu.edu.cn.
² College of Physical Science and Technology, Yangzhou University, Yangzhou, 225002, People's Republic of China. minzhou@yzu.edu.cn.
³ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, 611731, People's Republic of China.
⁴ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China.
⁵ College of Physical Science and Technology, Yangzhou University, Yangzhou, 225002, People's Republic of China.
⁶ Department of Chemical Engineering, Polytechnique Montréal, Montréal, QC, H3C 3A7, Canada.
⁷ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, 611731, People's Republic of China. ygzhang@uestc.edu.cn.
⁸ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054, People's Republic of China. ygzhang@uestc.edu.cn.

Abstract

Molybdenum carbide (Mo₂C) materials are promising electrocatalysts with potential applications in hydrogen evolution reaction (HER) due to low cost and Pt-like electronic structures. Nevertheless, their HER activity is usually hindered by the strong hydrogen binding energy. Moreover, the lack of water-cleaving sites makes it difficult for the catalysts to work in alkaline solutions. Here, we designed and synthesized a B and N dual-doped carbon layer that encapsulated on Mo₂C nanocrystals (Mo₂C@BNC) for accelerating HER under alkaline condition. The electronic interactions between the Mo₂C nanocrystals and the multiple-doped carbon layer endow a near-zero H adsorption Gibbs free energy on the defective C atoms over the carbon shell. Meanwhile, the introduced B atoms afford optimal H₂O adsorption sites for the water-cleaving step. Accordingly, the dual-doped Mo₂C catalyst with synergistic effect of non-metal sites delivers superior HER performances of a low overpotential (99 mV@10 mA cm^-2) and a small Tafel slope (58.1 mV dec^-1) in 1 M KOH solution. Furthermore, it presents a remarkable activity that outperforming the commercial 10% Pt/C catalyst at large current density, demonstrating its applicability in industrial water splitting. This study provides a reasonable design strategy towards noble-metal-free HER catalysts with high activity.

Keywords: Dual-doped; Hydrogen evolution reaction; Molybdenum carbide; Superior performances; Synergistic effect.