Electrochemical Study on Electroless Nickel Plating Using Sodium Borohydride as the Reductant

We studied electroless Ni-B plating with sodium borohydride as the reductant by linear sweep voltammetry. The effects of bath solution composition and operating conditions on the cathodic reduction and anodic oxidation were studied. Increases in the concentrations of nickel acetate and sodium borohydride accelerated the reduction of Ni2+ and the oxidation of BH4-, respectively. Ethylenediamine, sodium hydroxide, thiourea and saccharin sodium inhibited both the cathodic and anodic reactions to varying degrees. Additionally, sulfur in the additives promoted the dissolution of nickel. High temperature was beneficial to both the cathodic reduction and anodic oxidation.