화학공학소재연구정보센터
Journal of Electroanalytical Chemistry, Vol.421, No.1-2, 111-120, 1997
Preparation and Characterization of Nanocrystalline Composite (Nanocomposite) Films of Titanium-Dioxide and Nickel by Occlusion Electrodeposition
A new family of nanocrystalline composite films was developed for photoelectrochemical application by occlusion deposition of TiO2 particles from a nickel plating bath. The photoactivity of the resultant NiTiO2 films was examined under chopped-light illumination with a xenon are lamp in 0.1 M KNO3. A TiO2 dose in the nickel bath of 0.8 M, a deposition potential of - 0.8 V, a bath pH of 5.0, a bath temperature of 20 degrees C and a film deposition charge of 36mC (corresponding to a film ca. 0.7 mu m thick) were found to yield the best photoresponse for the resultant NiTiO2 films. The photoresponse of these nanocomposite films was compared with that of TiO2 layers on Ti supports, obtained either from thermal oxidation of titanium or by oxidative decomposition of aq. TiCl4 at 550 degrees C. Formate and acetate ions were employed as current-doubling agents in the 0.1 M KNO3 electrolyte for this comparative study. The current-doubling effect was seen to be the highest for the NiTiO2 films; possible mechanistic origins for this trend are discussed. Other characterizations of the NiTiO2 films, including analyses by laser Raman spectroscopy and X-ray photoelectron spectroscopy, are also discussed.