Electroplating and electroless plating of Ni through/onto a porous polymer in a flow cell

Porous Ni coatings on electrodes were produced by electroplating through the cells and pores of a generic 'high internal phase emulsion polymer' (PHIPE), a styrene-ethylhexylacrylate-divinylbenzene copolymer, and subsequent thermal decomposition of the polymer template. Electroplating was carried out from flowing solutions through a polymer block fitted in the interelectrode gap of a flow-by cell. The mass transfer conditions and the flow regime in the cell were also characterized. The structure of the porous electrodeposits thus produced was determined by the distortion of the electric field through the cells and pores of the insulating polymer and depends on the current density and the thickness of the polymer layer. Porous deposits plated at 5 mA cm(-2) showed high utilization of electroactive surface area when used as hydrogen evolving cathodes from alkaline solutions. Finally, Ni/PHIPE composite foams were prepared by Ni electroless plating through the polymer pores and their electrochemical surface area was evaluated.