Structural transformation of molybdenum carbide with extensive active centers for superior hydrogen evolution

• Published in: Nano energy 2022-07, Vol.98, p.107232, Article 107232
• Main Authors: Yang, Chenfan, Zhao, Rong, Xiang, Hui, Wu, Jing, Zhong, Wenda, Li, Xuanke, Zhang, Qin
• Format: Article
• Language: English
• Subjects: Hydrogen evolution; MoC/Mo2C; Multi-active center; Structural transformation
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2022.107232

Mo2C-based materials are expected to be extraordinary electrocatalysts for hydrogen evolution reaction (HER) due to their unique Pt-like electronic structures. However, the strong interaction between Mo and H as well as the scarce active centers impede their further applications. Herein, a facile and controllable route via Zn doping is proposed to weaken the H adsorption energy of Mo and create more active centers to boost the HER kinetics. A series of hierarchical branched MoC/Mo2C catalysts with promoted HER kinetics are constructed and well controlled by Zn-doping, where the structural transformation from Mo2C to MoC give rise to the optimized electronic structure and attenuate H adsorption energy. Besides, all Zn and Mo sites in Zn-MoC/Mo2C catalyst can be activated, and thereby dramatically increase the number of active centers as well as enhance the intrinsic catalytic activity. As expected, the Zn-MoC/Mo2C catalyst exhibits extremely low overpotential and Tafel slopes with excellent durability in both alkaline and acidic solutions. This work highlights a feasible strategy for enhancing hydrogen generation by dopant induced structural transformation and might provide an avenue for low-cost, efficient, and multifunctional electrocatalysts. TOC: The introduction of MoC into Mo2C via Zn doping optimizes the electronic configuration, leading to all the metal sites are responsible for superior HER. The achieved Zn-MoC/Mo2C-0.2 catalyst features extremely low overpotential and excellent stability in both acidic and alkaline solutions. This novel strategy provides a perspective for promoting the activity of transition metal carbides for HER. [Display omitted] •Zn doping can induce the structural transformation from Mo2C to MoC.•Introducing MoC into Mo2C can significantly optimize the electronic configuration.•All Zn and Mo sites in Zn-MoC/Mo2C catalyst can be activated for superior HER.•Zn-MoC/Mo2C catalyst features extremely low overpotential and excellent stability.