NANOCRYSTALLINE Pt FILMS BY MOCVD IN THE PRESENCE OF WATER VAPOR FOR ELECTRODE USE

摘要

The utilisation of water vapour during the CVD of Pt from platinum(II) acetylacetonate enabled the films to grow more slowly and more homogeneously along the reactor. The system structure, chemical composition and morphology as a function of the processing conditions were analyzed by means of XRD (X-ray Diffraction), XPS (X-ray Photoelectron Spectroscopy) and AFM (Atomic Force Microscopy). The performance of the Pt-films as electrode materials were investigated by cyclic voltammetry in aqueous solutions containing H_2SO_4 and Ru(NH_3)_6Cl_3. They displayed voltammograms with features very similar to those of bulk Pt electrodes. Larger than theoretically predicted, cathodic-to-anodic peak potential separations were obtained for very thin Pt-films for the Ru(NH_3)_6~(3+/2+) process, indicating ohmic drop effects.