Effect of gluconate addition on the electrodeposition of nickel from acidic baths

Effect of sodium gluconate on electrodeposition of nickel from acidic baths (chloride, sulphate, sulphate–chloride) was investigated. Distribution of nickel species in all solutions was calculated. Cyclic voltammetry and potentiostatic measurements showed that cathodic process was inhibited by sulphate and gluconate ions. Simultaneously, both types of ions improved buffer capacity of the baths. Two mathematical models of metal nucleation were tested. Thickness, morphology and microhardness of deposits as well as cathodic current efficiencies of nickel potentiostatic deposition were also presented.