采用循环伏安和计时电流技术考察氯化胆碱-乙二醇低共熔溶剂中镍在铂电极上的电沉积行为,利用扫描电子显微镜及X射线衍射技术研究电流密度对镍镀层形貌及织构变化的影响。结果表明:镍在氯化胆碱-乙二醇低共熔溶剂中的电沉积过程是准可逆的,其形核/生长过程遵循Scharifker-Hill三维形核模型。初始阶段,镍离子的形核/生长过程按三维连续形核机制,随后趋向于三维瞬时形核机制。随电流密度的增大,镀层厚度增加,晶粒尺寸减小,镍(111)晶面择优取向减弱,镀层表面形貌则由锥形颗粒状变为不规则的多面体颗粒状,最后变为圆球形胞状结构。
The Ni electro-crystallization behavior on copper electrode was investigated by cyclic voltammetry and chronoamperometry, the microscopic morphology and crystalline structure of the deposited layer at various current densities were examined using SEM and XRD techniques. The results show that the Ni deposition is quasireversible, the nucleation/growth process follows Scharifker-Hill three dimensional (3D) mode. The nucleation/growth conforms to 3D progressive mechanism at initial stage, and then, changes to 3D instantaneous progressive nucleation. With increasing the current density, the coating thickness increases, the size of nickel crystals decreases and the (111) fiber orientation growth decreases. The morphologies of Ni coating transform from large pyramid-like particles to irregular polyhedron-like particles, and then, becomes spherosome-like cellular.