Electrochemical Deposition of Pt Particles from Hexachloroplatinate(IV) and Tetrachloroplatinate(II) Ion Solutions

The behavior of Pt electrodeposition on n-Si is different between H2PtCl6 (Pt(IV)) and K2PtCl4 (Pt(II)) aqueous solutions. Immersion of bare n-Si wafers in a Pt(II) solution under an open-circuit condition deposits Pt particles on n-Si, but immersion in the Pt(IV) solution deposits no particles. In the Pt(IV) solution, silicon oxide is produced with holes injected into the Si valence band by the reduction reaction of Pt(IV) to Pt(II). The quantity of electrodeposited Pt on the glassy carbon at +0.10 V vs. SCE in the Pt(IV) solution was smaller than that of the Pt(II) case. Cyclic voltammetry shows that the electeroeposition behavior of Pt in the early stage is influenced by the substrates.