A novel two-dimensional hierarchical Mo2C/C-N hybrid fabricated via ionothermal route as a robust electrocatalyst for hydrogen evolution reaction. (20th December 2017)

• Record Type: Journal Article
• Authors: Zhi, Guolei; Liu, Baocang; Wang, Shasha; Huo, Lili; Gao, Zhiqing; Zhang, Jun
• Is Part Of: Electrochimica acta. Volume 258(2017)
• Page Start: 970
• Page End: 978
• Publication Date: 2017-12-20
• Subjects: Two-dimensional hierarchical structure -- Mo2C/C-N hybrid -- Ionothermal route -- Electrocatalyst -- Hydrogen evolution reaction; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.11.148
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Design of highly efficient noble-metal-free hydrogen evolution electrocatalysts is of great significance to the practical application of water-separation devices. Herein, we design a highly active and durable two-dimensional (2D) hierarchical Mo2 C/C-N hybrid with well-dispersed small Mo2 C nanocrystals decorated on nitrogen-doped carbon (C-N) frameworks via one-step ionothermal route. Encouragingly, the optimal 2D hierarchical Mo2 C/C-N hybrid shows a low onset potential of 6 mV, an overpotential of 98 mV at a cathodic current density of 10 mA cm −2, a Tafel slope of 60 mV dec −1, and a large exchange current density of 0.311 mA cm −2 in acidic medium. Moreover, it also displays outstanding long-term electrochemical stability, exhibiting almost 100% activity retention after 3000 cycles and 20 h of continuous testing at fixed overpotentials. The unique 2D structure of electrocatalyst possesses highly dispersed ultrasmall Mo2 C nanocrystals embedded in 2D layered C–N frameworks, excellent electron transportation, abundant active sites (Mo-C), and strong interaction between Mo2 C nanocrystals and C-N frameworks, leading to the remarkable catalytic activity and endurance for hydrogen evolution reaction over a wide pH range. The synthetic strategy is facile and inexpensive for large-scale production and also can be extended to fabricate various 2D hierarchical nanomaterials for electrocatalytic applications. Graphical abstract: