ELECTROCHEMICAL EPITAXIAL-GROWTH OF A PT(111) PHASE ON AN AU(111) ELECTRODE

The electrochemical deposition of platinum on an Au(111) single-crysta l electrode in acidic solutions containing H2PtCl6 was studied using a n electrochemical scanning tunneling microscope (STM) and electrochemi cal quartz crystal microbalance (EQCM). The STM investigation showed a n ordered adlayer of PtCl62- on the electrode surface during the elect rochemical deposition of platinum and a Pt(111)-(1x1) structure an the electrode surface after the electrode was rinsed with a Pt complex-fr ee solution. Formations of the Pt(111) bulk phase and surface structur e of Pt(111)-(1x1) were confirmed by X-ray diffraction (XRD) and the u nderpotential deposition of copper and hydrogen, respectively.