Effect of Tartaric Acid on Preparation of Dendritic Ultrafine Silver Powder by Electrolysis

Abstract:

In this paper, dendritic silver powders were prepared by electrolysis and the growth mechanism of tartaric acid on the morphological evolution of silver particles during electrochemical deposition was investigated. The effect of tartaric acid on the morphology and structure of the silver powder during deposition was analysed by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). In addition, cathodic polarisation (LSV), cyclic voltammetry (CV) and chronoamperometry (CA) were used to investigate the effect of tartaric acid on the electrochemical behaviour of dendritic silver powders prepared by electrolysis. The results showed that when 0 g/L tartaric acid was added to the solution, the silver ions formed a sphere-like structure at a current density of 850 A/m₂ ^, while when 0.05 g/L tartaric acid was added to the solution, the silver ions formed a rod-like structure at the same current density, and the cathodic polarization increased and the overpotential increased as the amount of tartaric acid added increased. When the amount of tartaric acid added to the solution was increased to 0.5 g/L tartaric acid, a dendritic silver powder with a particle size of about 3-4 um, a loose packing density of 1.1 g/cm₃ ^{and a vibrational density of 0.6 g/cm}₃ ^{and good} crystallinity was successfully prepared. The chrono-current results showed that the solution systems all followed a transient nucleation process, but the addition of tartaric acid affected the nucleation and growth kinetics of the silver and inhibited cathodic polarisation.

Key words:Dendritic silver powder; tartaric acid; electrochemical behaviour; deposition mechanism