We studied platinum-zinc alloy plating by adding zinc to an alkaline platinum bath that used hexahydroxoplatinate.
Hexachloroplatinate solution and potassium hydroxide were mixed to prepare a potassium hexahydroxoplatinate solution. Zinc oxide was dissolved into the potassium hydroxide solution. These solutions were then used to compose a platinum-zinc alloy plating bath.
We then analyzed deposition efficiency, alloy composition, crystal structure, and the appearance of the precipitated deposit.
Deposition efficiency increased as zinc was added. When up to 0.7g/L of zinc had been added, the deposit contained 90wt% of platinum and 10wt% of zinc. The ratio of zinc to platinum in the deposit was higher than that in the plating solution.
A mirror-bright platinum-zinc alloy of 3μm was plated on copper panel and the substrate was dissolved in nitric acid to fabricate a foil. The foil, however, was destroyed by bending.
Zinc codeposited at 5wt% yielded a mirror-bright deposit, but the ductility of the deposit was poor.