The effect of a nickel oxide (NiO(x)) seed layer on the crystallization and photocatalytic activity of the sequentially plasma-enhanced chemical vapor deposited amorphous titanium oxide (TiO(x)) thin film processed by a post-annealing process was investigated. The evolution of the crystalline structures, chemical bond configurations, and surface/cross-sectional morphologies of the annealed TiO(x) films, with and without a NiO(x) seed layer, was examined using X-ray diffractometer, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscope measurements. Thermo- and photo-induced hydrophilicity was determined by measuring the contact angle of water droplet. Photocatalytic activity after UV light irradiation was evaluated from the decolorization of a methylene blue solution. The crystallization temperature of the TiO(x) film, deposited on a NiO(x) seed layer, was found to be lower than that of a pure TiO(x) film, further improving the thermo- and photo-induced surface super-hydrophilicity. The TiO(x) film deposited onto the NiO(x) seed layer, resulting in significant cluster boundaries, showed a rough surface morphology and proved to alleviate the anatase crystal growth by increasing the post-annealing temperature, which yielded a more active surface area and prohibited the recombination of photogenerated electrons and holes. The photocatalytic activity of the NiO(x)/TiO(x) system with such a textured surface therefore was enhanced and optimized through an adequate post-annealing process. (C) 2011 Elsevier B.V. All rights reserved.