On the Mechanism of Electroless Ni‐P Plating
On the Mechanism of Electroless Ni‐P Plating
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DOI：
10.1149/1.2055125
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发表时间：
1994-09
影响因子：
3.9
通讯作者：
L. Abrantes;J. Correia
中科院分区：
文献类型：
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作者：
L. Abrantes;J. Correia
采用动电位法和开路电位法研究了次磷酸根离子作为还原剂在氯化物基溶液中镍的化学沉积机理。结果表明，混合势理论不能描述该体系。这是由于所涉及的机制的性质。假设该过程通过次磷酸根离子的吸附初始化，然后是主要还原剂物质的均分解，导致形成原子和离子自由基，其促进镍和次磷酸还原以产生Ni-P存款。观察到Ni-P的初始沉积阶段，揭示了导致催化活性增加的基底诱导与电流位移过程无关，而是与允许次磷酸根离子吸附/分解的电化学条件的建立有关。实验结果与所提出的机理吻合较好。
The electroless deposition mechanism of nickel, in a chloride‐based solution, using hypophosphite ion as reducing agent was examined using potentiodynamic method and open‐circuit potential measurements. The results indicate that the mixed potential theory is unable to describe this system. This is due to the nature of the involved mechanism. It is assumed that the process is initialized by adsorption of hypophosphite ions, followed by the homolysis of primary reductant species, resulting in the formation of atomic and ionic radicals which promote nickel and hypophosphorous acid reduction to originate the Ni‐P deposit. The initial deposition stages of Ni‐P were observed, revealing that the substrate induction, which leads to an increase in the catalytic activity, is not related to a galvanic displacement process, but rather to the establishment of the electrochemical conditions which allow the adsorption/breakdown of the hypophosphite ions. The experimental results are in good agreement with the proposed mechanism.