Electrodeposition of platinum metal and platinum-rhodium alloy on titanium substrates

A method for application of an adherent platinum (Pt) and platinum-rhodium (Pt-Rh) alloy plate to a titanium (Ti) substrate includes steps of surface pretreatment, anodization, and electrodeposition of Pt and Pt-Rh alloy from their electrolytic baths consisting of H2Pt^sub 2^Cl^sub 6^·6H2O (20 gL^sup -1^), and HCl (300 gL^sup -1^) for a Pt bath. The Pt-Rh bath consists of H2Pt^sub 2^Cl^sub 6^·6H2O (20 gL^sup -1^), and HCl (300 gL^sup -1^) and RH2 (SO^sub 4^)^sub 3^ (2 gL^sup -1^). At the optimum conditions of electroplating, the Pt and Pt-Rh deposits were formed over the anodized Ti substrates with high adhesion, brightness, and high current efficiency (35.33% for Pt and 70.38% for the Pt-Rh alloy).[PUBLICATION ABSTRACT]