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线性扫描伏安法和电位阶跃法被用来研究氯化钾镀锌溶液中锌在玻璃碳上电结晶的初期阶段。发现锌在该基体上的沉积没有经历UPD过程。在本实验条件下,成熟晶核的生长受溶液中锌离子的扩散所控制,而晶核形成的机理依有无添加剂存在而异。通过分析恒电位暂态,求出锌离子的扩散系数D,以及不同过电位η下的成核速度常数A和晶核数密度N_0。A和η的关系表明“原子模型”比经典的成核模型更适合于本研究体系。N_0与η的经验关系式由曲线拟合而得。本文着重讨论了过电位和添加剂对成核作用的影响。
Linear sweep voltammetry and potentiometric steps were used to investigate the initial phase of zinc electrocrystallization on glassy carbon in a potassium chloride zinc plating solution. The deposition of zinc on this substrate was found not to have undergone the UPD process. Under the experimental conditions, the growth of mature nuclei is controlled by the diffusion of zinc ions in the solution, while the mechanism of nuclei formation depends on the existence of additives. The diffusion coefficient D of zinc ions and the nucleation rate constant A and the nucleus number density N_0 under different overpotential η were obtained by analyzing the transient potentials. The relationship between A and η shows that the “atomic model” is more suitable for the research system than the classical nucleation model. The empirical relationship between N_0 and η is derived from the curve fitting. This article focuses on the effects of over-potential and additives on nucleation.