Potential-Induced Shape Evolution of Gold Nanoparticles Prepared on ITO Substrate

A well-defined potential gradient was introduced to the surface of indium tin oxide (ITO) during the seed-mediated synthesis of anisotropic gold nanoparticles (AuNPs) on substrates. Benefiting from this potential gradient, we found an evolution of particle morphology as a function of the position potential on ITO substrates. With increasing potential, gold triangular nanoprisms and triangular, hexagonal, and polygonal nanoplates were successively produced as the main products. The results obtained in a traditional three-electrode cell demonstrated a similar morphology evolution trend, confirming that substrate potential is one of the key factors controlling the morphology of nanoparticles. The different adsorption behavior of capping agents on gold facets under different potentials was believed to be the cause of the potential-induced particle morphology evolution. This work offers opportunities for potential-assisted shape-selective synthesis of nanoparticles on conducting substrates.