泡沫镍基镍硫合金涂层形貌、结构和析氢性能研究  

Study on micro-appearance,structure and properties of hydrogen evolution reaction of nickel-sulphur alloy coatings electrodeposited on the nickel foam substrate

作　　者：何捍卫[1] 刘红江[1] 刘芳[1] 周科朝[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《功能材料》2006年第1期87-91,共5页Journal of Functional Materials

基　　金：国家高技术研究发展计划(863计划)资助项目(2003AA305980)

摘　　要：在含有柠檬酸、硫脲和少许糖精的Watt镀液中,用电沉积的方法在镍泡沫基体上制备了镍硫合金涂层。各层涂层的形貌用SEM分析,各层硫量的分布用EDX测量。第1层涂层的结构用XRD测定。对各种电极包括镍泡沫基、镍网基上镍硫涂层电极,空白镍泡沫、镍网电极等的极氢电位进行了测量,研究了不同温度下镍泡沫基镍硫涂层电极的析氢活性。结果表明,镍泡沫基Ni-S涂层电极的析氢活性比镍网基Ni-S涂层电极活性高得多。镍泡沫各层硫量呈梯度的分布规律,由表及里硫含量逐步降低,中心层硫含量最低。各层表面微细颗粒大小及其均一性不相同,第1层的颗粒尺寸大于其它层的颗粒,其大小均一性也较其它层差。镍硫涂层是镍和Ni3S2组成的非晶态,使涂层具有丰富的表面积和氢气析出反应的活性中心。在加热的电解液中,在60℃以下和60℃以上的温区内电极析氢反应的机制不完全一样,受温度影响的程度也不一样。4000A/m2、90℃时,这种电极的析氢电位比15℃时析氢电位低180mV。Nickel sulfur electrode was obtained on the nickel foam by electrodeposition method in a modified Watts bath into which thiourea （TU）, citric acid and a little of saccharin were added. The micrographs of various layers of nickel sulphur coatings were investigated by SEM. The distributions and mass contents of sulphur in nickel sulphur coatings were measured by EDX. The structures of the first layer of nickel sulphur coating were determined by XRD. The hydrogen evolution potentials of various electrodes, including nickel sulphur coatings on foam and net nickel substrates, pure nickel foam and nickel net were measured, and at different temperatures the hydrogen evolution potentials of nickel sulphur coatings on the nickel foam were also measured. Results indicated that the hydrogen evolution reaction activity of amorphous Ni-S coatings electrodeposited on the nickel foam substrate is much higher than that electrodeposited on the nickel net substrate. The distributions of sulphur contents on the various layers are gradient, contents of sulphur gradually decrease from surface to inside. The sizes of particles on the various layers are not the same. The sizes of particles on the first layer are bigger than ones on the other layers and their uniformities are also poorer. The structure of the nickel sulphur coating which is composed of Ni and Ni3S2 is amorphous. In the presence of Ni3S2, the surface area of the coatings is very abundant and there are many active centers in the coatings. In hot electrolyte, the mechanisms of hydrogen evolution reaction are not the same respectively in the temperature ranges 15-60℃ and 60-90 ℃. When the current density is 4000A/m^2, the potenial of hydrogen evolution reaction at 15℃ is higher than that at 90℃ for 180mV.

关 键 词：镍硫涂层 电沉积 镍泡沫 析氢电极 

分 类 号：TQ153.2[化学工程—电化学工业]