†College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124, China.
ACS Nano. 2015 May 26;9(5):5125-34. doi: 10.1021/acsnano.5b00425. Epub 2015 Apr 17.
Single nanocrystalline tungsten carbide (WC) was first synthesized on the tips of vertically aligned carbon nanotubes (VA-CNTs) with a hot filament chemical vapor deposition (HF-CVD) method through the directly reaction of tungsten metal with carbon source. The VA-CNTs with preservation of vertical structure integrity and alignment play an important role to support the nanocrystalline WC growth. With the high crystallinity, small size, and uniform distribution of WC particles on the carbon support, the formed WC-CNTs material exhibited an excellent catalytic activity for hydrogen evolution reaction (HER), giving a η10 (the overpotential for driving a current of 10 mA cm(-2)) of 145 mV, onset potential of 15 mV, exchange current density@ 300 mV of 117.6 mV and Tafel slope values of 72 mV dec(-1) in acid solution, and η10 of 137 mV, onset potential of 16 mV, exchange current density@ 300 mV of 33.1 mV and Tafel slope values of 106 mV dec(-1) in alkaline media, respectively. Electrochemical stability test further confirms the long-term operation of the catalyst in both acidic and alkaline media.
首次通过热丝化学气相沉积（HF-CVD）法，在垂直排列的碳纳米管（VA-CNTs）的尖端上直接用钨金属与碳源反应，合成了单纳米晶碳化钨（WC）。VA-CNTs 保持了垂直结构的完整性和定向排列，对纳米晶 WC 的生长起到了重要的支撑作用。由于 WC 颗粒在碳载体上具有高结晶度、小尺寸和均匀的分布，所形成的 WC-CNTs 材料在析氢反应（HER）中表现出优异的催化活性，在酸性溶液中给出 η10（驱动电流为 10 mA cm(-2)时的过电势）为 145 mV，起始电位为 15 mV，在 300 mV 时的交换电流密度@为 117.6 mV，塔菲尔斜率值为 72 mV dec(-1)，在碱性介质中 η10 为 137 mV，起始电位为 16 mV，在 300 mV 时的交换电流密度@为 33.1 mV，塔菲尔斜率值为 106 mV dec(-1)。电化学稳定性测试进一步证实了催化剂在酸性和碱性介质中的长期运行。
