Correlation between crystal structure and morphology of potentiostatically electrodeposited silver dendritic nanostructures

Abstract

Silver dendritic nanonstructures obtained by the potentiostatic electrolysis from different electrolytes at different overpotentials were characterized by the scanning electron microscopy (SEM) technique and X-ray diffraction analysis of the produced particles. The needle-like and fern-like dendrites were formed from the nitrate electrolyte at overpotentials inside and outside plateaus of the limiting diffusion current density, respectively. The three-dimensional pine-like dendrites constructed from approximately spherical grains were formed from the ammonium electrolyte at overpotentials both inside and outside plateaus of the limiting diffusion current density. The morphology of silver dendrites was correlated with their crystal structure at the semi quantiative level. The change of crystal orientation from the strong (111) preferred orientation for the needle-like dendrites to almost randomly orientied spherical grains in the pine-like dendrites obtained at the overpotential outside the plateau of the limiting diffusion current density was observed. This trend in change of crystal orientation and morphology of Ag nanostructures was accompanied by considerable increase of the specific surface area (SSA) of the produced powders. The average crystallite sizes were in the range of 38-50 nm, proving nanostructural character of the formed Ag particles.