Size-Dependent Electrochemical Metal Growth Kinetics

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.

Automated summary

This work investigates the effect of the size of chemically preformed gold nanoparticles (seeds) on the electrochemical deposition of gold onto their surface. The growth potential and current strongly depend on the size of the seeds due to size-dependent kinetics of the growth process. The electrochemical reversibility is determined by the size of the gold nanoparticles, scan rate, metal precursor concentration, and coverage of gold nanoparticles on the surface.