A novel two-dimensional hierarchical Mo2C/C-N hybrid fabricated via ionothermal route as a robust electrocatalyst for hydrogen evolution reaction
A novel two-dimensional hierarchical Mo2C/C-N hybrid fabricated via ionothermal route as a robust electrocatalyst for hydrogen evolution reaction
复制标题
通过电离热途径制备的新型二维分级Mo2C/C-N杂化物作为析氢反应的稳健电催化剂
DOI：
10.1016/j.electacta.2017.11.148
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发表时间：
2017
影响因子：
6.6
通讯作者：
Zhang Jun
中科院分区：
文献类型：
--
作者：
Zhi Guolei;Liu Baocang;Wang Shasha;Huo Lili;Gao Zhiqing;Zhang Jun
高效无贵金属析氢电催化剂的设计对水分离装置的实际应用具有重要意义。在这里，我们设计了一种高活性和耐用的二维(2D)层次型Mo2C/C-N杂化材料，通过一步离子热法在掺氮碳(C-N)骨架上修饰了分散良好的小Mo2C纳米晶。令人鼓舞的是，最优的2D分级Mo2C/C-N杂化材料在阴极电流密度为10 mA/cm−2时，起始电位为6 mV，过电位为98 mV，塔菲尔斜率为60 mV/−1，在酸性介质中的大交换电流密度为0.311 mA/cm−2。此外，它还表现出出色的长期电化学稳定性，在固定过电位下进行3000次循环和20h的连续测试后，活性保持率几乎为100%。电催化剂独特的2D结构具有高度分散的超小Mo2C纳米晶嵌入2D层状C-N骨架，良好的电子传输，丰富的活性中心(Mo-C)，以及Mo2C纳米晶与C-N骨架之间强烈的相互作用，使其在较宽的pH范围内具有显著的催化活性和耐氢反应性能。该合成方法简单易行，成本低廉，适合于大规模生产，还可用于制备各种电催化应用的二维层状纳米材料。
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 Mo2C/C-N hybrid with well-dispersed small Mo2C nanocrystals decorated on nitrogen-doped carbon (C-N) frameworks via one-step ionothermal route. Encouragingly, the optimal 2D hierarchical Mo2C/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−2in 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 Mo2C nanocrystals embedded in 2D layered C–N frameworks, excellent electron transportation, abundant active sites (Mo-C), and strong interaction between Mo2C 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.