Ni-W-Cr脉冲纳米复合电极的制备及性能  

Preparation and Properties of Ni- W- Cr Pulsed Nano-Composite Electrodes

作　　者：张艳[1] 陈丽凤[1] 李天然[1] 

机构地区：[1]沈阳工业大学理学院,辽宁沈阳110870

出　　处：《材料保护》2016年第2期6-9,84,共4页Materials Protection

摘　　要：为获得高催化析氢性能的电极,采用脉冲电沉积法,通过调节工艺参数,在碳钢表面制备了较佳的NiW合金电极,在此基础上,在镀液中添加纳米Cr粉制备Ni-W-Cr纳米复合电极;采用SEM、电化学测量(阴极极化曲线、EIS技术)、XRD等方法考察了复合镀层的表面形貌、组织结构及性能。结果表明:镀液中加入不同含量的纳米Cr粉改变了镀层的表面形貌;纳米Cr粉的加入影响了电极原子间的协同效应,使电极的析氢过电位正移。镀液中纳米Cr粉含量为90 g/L时,制备的纳米复合电极的析氢过电位(氢相对于参比电极的析出电位)最正,为-1.254 V,相对于最佳的Ni-W合金仍提高了48 m V。EIS谱拟合的电极阻值与阴极极化曲线的结果相对应。Ni-W合金电极中存在不同的Ni-W合金形态,Ni-W-Cr脉冲纳米复合电极也存在不同的合金形态。Cr粉的加入明显降低了镀层的粒径,且电极发生了畸变,导致晶界增多,晶格缺陷增加,而晶格缺陷和位错处的原子具有较高的能量而可视为反应活性中心,因而纳米Cr粉的加入增加了反应活化中心,从而降低了析氢过电位,提高了镀层的析氢性能。On the basis of the Ni-W alloy electrode on carbon steel obtained by pulsed electrodeposition with regulating the process parameters,the Ni-W-Cr nano-composite electrode was prepared in the plating solutions containing Cr nano- powders. SEM,electrochemical measurements( cathodic polarization curve,EIS) and XRD methods were used to analyze the surface morphology,organization structure and performances of composite coating, respectively. Results showed that adding different contents of Cr nano-powders in plating solution changed the surface morphology of coating. The addition of Cr nano-powders affected the cooperativity between the electrode atoms,and made the hydrogen overpotential of electrode positive. When the content of Cr nano-powders in plating solution was 90 g/L,the prepared nano-composite electrode had the max-imum hydrogen overpotential and the value was- 1. 254 V,higher 48 mV than that of the optimum Ni-W alloy. In addition,the electrode resistance fitted by EIS patterns was corresponding to that by cathodic polarization curve. The Ni-W alloy electrode had different Ni-W alloy structures,and the Ni-W-Cr pulsed nano-composite electrode also had different alloy structures. The addition of Cr nano-powders markedly reduced the particle sizes of coating,and the electrode became distorted,which caused the increases of crystal boundary and crystalline host lattice imperfection. The atoms in crystalline host lattice imperfection and dislocation could be regarded as reactive active center due to higher energy. Thus, the addition of Cr nano- powders increased amounts of the reactive active centers,reduced the hydrogen overpotential and improved the hydrogen evolution performance of alloy.

关 键 词：Ni-W-Cr 纳米复合电极 催化析氢 脉冲电沉积 碳钢 

分 类 号：TG174.4[金属学及工艺—金属表面处理]