活化剂硫对镍阳极溶解行为及其残渣率的影响

Effect of Activator Sulfur on the Dissolution Behavior and Residual Rate of Nickel Anode

为了抑制镍阳极的钝化,改善电镀镍阳极的溶解性能,降低镍阳极的残渣率,研究了活化剂硫对镍阳极溶解行为及其残渣率的影响。采用电化学工作站研究了阳极极化曲线,通过光学显微镜和扫描电子显微镜等观察研究了镍阳极溶解的宏观、微观形貌,利用赫尔槽试验比较活化剂对镀层性能的影响。结果显示:1×10^(-4)mol/L Na_(2)S_(2)O_(3)能够显著提高镍的致钝电流密度;通过电位-时间曲线对比可知,硫元素的加入对镍阳极溶解有明显的钝化抑制作用,表现在能够在较大电流密度区间内降低电极电位;活化剂硫的加入能够明显改善镍阳极的溶解情况,残渣率从1.16%下降到0.36%;通过赫尔槽试验的镀层对比可知,硫活化剂的加入对镀层外观无明显影响;在活化剂硫的作用下,氧化镍与硫反应生成了硫化镍与氧气,氧气脱附使得镍阳极表面溶解更加均匀。

For inhibiting the passivation of nickel anodes,improving the solubility of electroplated nickel anodes and reducing the residual rate of nickel anodes,the influences of activator sulfur on the dissolution behavior and residual rate of nickel anodes were studied.Subsequently,an electrochemical workstation was used to study the anode polarization curve,the macroscopic and microscopic morphologies of nickel anode dissolution were studied through optical microscope and scanning electron microscope observation,and the Hull cell experiment was used to compare the effect of activator on the coating performance.Results showed that 1×10^(-4)mol/L Na_(2)S_(2)O_(3)could significantly increase the passivation current density of nickel.From the potential-time curves,the addition of sulfur had a significant passivation inhibitory effect on the dissolution of nickel anodes,which indicated that the electrode potential declined in the interval of larger current density.Meanwhile,the addition of activator sulfur could significantly improve the dissolution of nickel anodes,and the residue rate was reduced from 1.16%to 0.36%.Through the comparison of coatings in the Hull cell experiment,it could be obtained that the addition of sulfur activator had little effect on the appearance of the coating.Under the action of activator sulfur,nickel oxide reacted with sulfur to form nickel sulfide and oxygen,and oxygen desorption made the surface of nickel anode dissolve more uniformly.