Size-Dependent Electrochemical Metal Growth Kinetics
Size-Dependent Electrochemical Metal Growth Kinetics
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DOI：
10.1021/acs.jpcc.2c08879
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Harikrishnan N Nambiar;F. Zamborini
中科院分区：
文献类型：
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作者：
Harikrishnan N Nambiar;F. Zamborini
本研究探讨了电化学沉积（ECD）在化学预成型的金纳米颗粒（NPs）上作为金纳米颗粒尺寸的函数。由于生长过程中不同的Au NP大小依赖动力学，因此生长势和电流在很大程度上取决于预成型Au NP（种子）的大小。电化学可逆性取决于Au NP的大小、扫描速率、金属前驱体浓度（[AuCl4 -]）和Au NP的覆盖率。Au NPs需要达到一个临界的总表面积，以具有足够的活性面积，使整个电极的ECD在电化学上可逆，并在线性扩散传质限制条件下运行。较小的Au NPs需要较少的总表面积才能达到这一条件，因为它们具有更高的每表面积活性，这一点尚不完全清楚，但可能是由于它们表面上较大比例的缺陷，例如边缘和角落原子位置。
This work explores the electrochemical deposition (ECD) of Au onto chemically preformed Au nanoparticles (NPs) as a function of Au NP size. The growth potential and current depend strongly on the size of the preformed Au NPs (seeds) due to different Au NP size-dependent kinetics of the growth process. Electrochemical reversibility depends on the Au NP size, scan rate, metal precursor concentration ([AuCl4–]), and Au NP coverage. The Au NPs need to reach a critical total surface area to have enough active area to cause the ECD over the entire electrode to be electrochemically reversible and operate under linear diffusion mass transfer-limited conditions. The smaller Au NPs require less total surface area to reach this condition because they have higher activity per surface area, which is not fully understood but could be due to a greater percentage of defects on their surface, such as edge and corner atom sites.