Nanocomposite films consisting of TiO2 particles and Zn (thickness, 10 to 15 mu m) were formed on steel plates (TiO2-Zn/steel) by using an occlusion electrodeposition method. Scanning electron micrographs demonstrated that TiO2 particles were incorporated throughout the film. The TiO2 uptake increased significantly with addition of NOS ions to the electrodeposition bath. A positive con elation was observed between the TiO2 uptake and the photocatalytic activity for gas-phase oxidation of CH3CHO. Postannealing of the TiO2-Zn/steel sample in air at 673 K produced ZnO whiskers with a preferred orientation of(10 (1) over bar 1) plane, while the same treatment of the Zn/steel sample yielded granular ZnO polycrystals. The TiO2 particles-ZnO whiskers composite film exhibited a very high photocatalytic activity, which was greater than of the TiO2-Zn/steel sample by a factor of 1.5.