纳米晶WC-Co-Ni复合材料的制备及其电催化性能

采用喷雾干燥-气固反应法制备了具有介孔结构的纳米晶碳化钨-钴-镍(WC-Co-Ni)复合材料. 通过XRD, SEM, EDS和粒径分析等测试手段对样品的形貌、物相组成、化学成分、粒径分布进行了表征, 采用线性扫描法对WC-Co-Ni复合材料在氢析出反应中的电催化性能进行了评价. 结果表明, WC-Co-Ni复合材料由缺碳六方WC相、立方Co相和立方Ni相组成, 化学成分为W, C, Co和Ni, W与C的原子比接近1∶1; WC-Co-Ni复合材料具有空心球状或层状形貌, 其表面具有介孔结构; 样品颗粒的粒径集中分布在3～30 µm, 该区间内样品分布呈单分散性, 其中位径(d50)为10 µm; 在碱性溶液中, 复合材料对氢析出反应的电催化性能明显强于具有介孔结构的碳化钨样品.

Preparation and Electro-catalytic Property of Nano-crystalline Tungsten Carbide-Cobalt-Nickel Composite

The nano-crystalline tungsten carbide-cobalt-nickel (WC-Co-Ni) composite with meso-porosity was prepared by a spray drying-gas solid reaction. The samples were characterized by XRD, SEM, EDS and distribution of particle sizes, respectively. The electro-catalytic properties of the WC-Co-Ni composite for the hydrogen evolution reaction in basic solution were investigated using the electrochemical technique of linear sweep voltammetry. The XRD results show that the sample is composed of tungsten carbide, cobalt and nickel. The EDS results show that the ratio of W/C is near 1. SEM images indicate that the morphology of the sample is hollow globe or laminated structure with meso-porosity. The particle diameter of the composite can be well controlled in the range from 3 to 30 µm, and the average diameter (d50) of the monodisperse particle is 10 µm. The electrocatalytic activity of the WC-Co-Ni composite for the hydrogen evolution reaction is higher than that of hollow globe tungsten carbide with mesoporosity in basic solution. The improvement of the electrocatalytic activity of the sample can be attributed to its components and composite structure.