摘要
脉冲电沉积合金层较为复杂,目前尚未实际应用。采用脉冲电沉积技术制备了Ni-W-Fe-La纳米晶合金析氢镀层,利用扫描电镜、X射线衍射仪、能谱仪等设备测试了合金镀层的形貌、结构和组成。研究了制备工艺对镀层析氢性能的影响。确定了合金镀层的最佳制备工艺条件:机械搅拌下,控制平均电流密度Jm=5A/dm2,峰值电流密度Jp=14A/dm2,占空比R为35%,脉冲频率f=150Hz,pH值6.0～6.5,脉冲时间30min,镀液温度35℃。结果表明:制备的Ni-W-Fe-La镀层为纳米级镀层,其晶粒尺寸为48.73nm;稀土La元素的加入能够明显改变镀层表面形貌、晶粒尺寸以及镀层的耐蚀和析氢电催化活性,析氢电位比直流电沉积所得的同类镀层明显正移。
Nanocrystalline Ni-W-Fe-La alloy coatings were obtained by pulse electrodeposition.The morpholo-gy,microstrutre and composition of the alloy coatings were ana-lyzed by means of scanning electron microscopy,X-ray diffraction and energy dispersive spectrometry.The effect of electrodeposi-tion conditions on the hydrogen evolution performance of the alloy coatings was investigated,and the optimized conditions for pre-paring the alloy coatings were established.Results indicate that it is feasible to prepare nanocrystalline Ni-W-Fe-La alloy coating with a grain size of 48.73 nm at an average current density of 5 A/dm22222,peak current density of 14 A/dm22222 ,pulse duty cycle of 35 % ,pulse frequency of 150 Hz,pH value of 6.0 ～ 6.5 ,pulse duration of 30 min and bath temperature of 35 ℃ under mechani-cal stirring.The introduction of rare earth La resulted in changes of morphology,grain size,anticorrosion behavior and hydrogen evolution electrocatalytic activity of the alloy coating,leading to obvious shift of hydrogen evolution potential towards positive di-rection as compared with the same alloy coating prepared by di-rect current electrodeposition.
出处
《材料保护》
CAS
CSCD
北大核心
2010年第6期42-45,61,共5页
Materials Protection
基金
广西科学基金项目(桂科基0731015)
广西研究生教育创新人才联合培养基地项目
关键词
脉冲电沉积
纳米晶合金
稀土
析氢性能
pulse electrodeposition
nanocrystalline alloy
rare earth
hydrogen evolution performance
