Mass transfer to a nanostructured nickel electrodeposit of high surface area in a rectangular flow channel

Abstract

Nanostructured nickel was electrodeposited on a stainless steel plate. The convective-diffusion mass transfer to this nanostructured electrode was compared to that of a planar, mirror polished solid nickel electrode using the limiting current technique, for the reduction of ferricyanide, hexacyanoferrate (III) ion in an undivided cell. The effect of introducing a turbulence promoter into the electrolyte channel was also evaluated for each electrode under steady state conditions. At a Reynolds number of 700, the product of mass transfer coefficient and active electrode area, kLA for the nanostructured nickel electrode increases over 11 times compared to the mirror polished planar nickel electrode. In the presence of a turbulence promoter, the nanostructured nickel electrode shows an approximately 23 times increase in kLA compared to the planar mirror polished nickel electrode. The dimensionless mass transfer correlations Sh=aRebScdLee are compared to others in the literature.