Study of the electrodeposition of silver nanoparticles on glassy carbon by galvanostatic control

Abstract

Electrodeposition of silver nanoparticles from an ammonium complexated silver electrolytic bath was accomplished using a low-resistance capillary cell. The advantage of the proposed methodology is that electrodeposition is not limited to a specific geometrical shape of the electrode and only small volumes of electrolyte are required. The pulse current technique is discussed considering a fixed charge transfer on a glassy carbon electrode, finding that a pulse of 1.70mA/cm2 generates high density of small particles with little variability. It was found that the 92% of the total duration of the current pulse is used to achieve the stabilization of the potential, which is associated to the particle growth limited by diffusion of the silver ions. The comparison between the galvanostatic and potentiostatic electrodeposition shows that the galvanostatic control generates smaller particles with higher density compared to the potentiostatic pulse. However the potentiostatic pulse lead to a better distribution on the surface delimited by the droplet. The morphological characterization was carried out by Scanning Electron Microscope (SEM) revealing that silver follows a progressive nucleation.