Ultrafast synthesis of molybdenum carbide nanoparticles for efficient hydrogen generation
Ultrafast synthesis of molybdenum carbide nanoparticles for efficient hydrogen generation
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超快合成碳化钼纳米颗粒以高效产氢
DOI：
10.1039/c7ta06266d
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发表时间：
2017-11-21
影响因子：
11.9
通讯作者：
Zhang, Chi
中科院分区：
文献类型：
--
作者：
Lv, Cuncai;Huang, Zhipeng;Zhang, Chi
提出了一种简便、超快的碳化钼包覆少层碳(MOC/C)的合成方法，并研究了减少碳包覆厚度对其析氢催化活性的影响。在0.5M硫酸溶液中，MOC/C在144 mV的过电位下产生20 mA cm(-2)的电流密度，Tafel斜率为63.6 mV dec(-1)，并在长期电解条件下稳定工作。MoC/C是迄今报道的最活跃的碳化物电催化剂之一，尽管MoC甚至不是碳化钼最活跃的相，而且MOC/C的比表面积很小。互补密度泛函理论计算揭示了这种新颖的催化剂设计，表明增加碳层厚度会导致复合体系失去MOC的特征，表现出更像碳表面的行为，从而导致其活性降低。
A facile and ultrafast synthesis of molybdenum carbide coated with few-layer carbon (MoC/C) has been developed, and the effect of reducing the thickness of the carbon coating on its catalytic activity in the hydrogen evolution reaction (HER) has been demonstrated. MoC/C produces a current density of 20 mA cm(-2) at an overpotential of 144 mV and a Tafel slope of 63.6 mV dec(-1) in 0.5 M H2SO4, and works stably under long-term electrolysis. MoC/C is one of the most active carbide electrocatalysts reported thus far, although MoC is not even the most active phase of molybdenum carbide and MoC/C has a small surface area. Complementary density functional theory calculations have afforded insight into this novel catalyst design, showing that increasing the thickness of the carbon layer leads to the composite system losing the characteristics of MoC and behaving more like a carbon surface, and thereby resulting in a reduction in HER activity.