Impact of key deposition parameters on the morphology of silver foams prepared by dynamic hydrogen template deposition

Abstract

The potentiostatic deposition of porous Ag foams from a new stable thiocyanate based bath using hydrogen bubbles as a dynamic template during deposition was investigated. The influence of the electrolyte content, deposition potential and deposition time on the micro- and nanoscale morphology of the Ag form was examined. The formation of three main morphological forms on the nanoscale level: dendrites, a framework of identical particles, and agglomerates of inhomogeneous particles with big Ag granules distributed on the foam surface, was demonstrated by the analysis of the scanning electron microscopy (SEM) data. The quality of the structures obtained was examined by energy dispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD). It was found that the experimental parameters had a huge effect on the morphology of Ag on both the micro- and nanoscale. The structures with the most efficient geometry from the technological point of view were obtained with the correct combination of parameters, viz. high concentrations of NH 4 + and Ag + in conjunction with a sufficient deposition potential and time. Foams with roughness factors as high as 1100 were obtained, showing a high geometrical area normalized double-layer capacitance and relatively high gravimetric capacitance of 22 mF cm −2 and 2.4 F g −1, respectively.