Nb-doped TiO2 thin films as photocatalytic materials

Abstract

Amorphous undoped and Nb-doped films were obtained by the spin coating method. The films have a compact structure, as revealed by scanning electron microscopy, and are very thin, with thickness values under 100 nm. The photocatalytic activity of the films was evaluated by observing the decomposition of an oleic acid solution under UV irradiation, and by studying the change in the optical transmittance of an aqueous solution containing methylene blue, in the presence of the UV-irradiated films. More than 30 h, depending on doping, are needed to recover their initial contact angles before applying oleic acid. The increase of the optical transmittance of the methylene blue solution confirms the photocatalytic degradation of methylene blue on the Nb-doped TiO 2 films. X-ray photoelectron spectroscopy studies, performed to detect the presence of the carbon on the irradiated surface of the films, drive to the conclusion that at the surface of the films, even for contact angles close to 0°, the presence of carbon still can be detected, which demonstrates that hydrophilicity is ruled by a different mechanism than photocatalysis.

Selective Adsorption and Photocatalytic Clean‐Up of Oil by TiO2 Thin Film Decorated with p‐V3D3 Modified Flowerlike Ag Nanoplates

“…On the other hand, the TiO 2 thin film surface was also contaminated with oleic acid and exposed to UV light for 10 h. XPS investigation showed a gradual decrease in peak intensity and concentration % of C 1s while those increase in case of both Ti 2p and O 1s (Figure S6 and Table S2, Supporting Information). [40] Here, high stability of the p-V 3 D 3 coating might arise due to the presence of the SiO bond (which can also promote a strong adhesion of the polymer layer to the Ag/TiO 2 surface. [19] This clearly shows that a p-V 3 D 3 layer is more suitable than the conventional PTFE coating for oil-water separation and photocatalytic clean-up application.…”

Ceramic tiles coated with Zr‐Ag co‐doped TiO2 thin film for indoor air purifying and antimicrobial applications

“…The increase in the Ti 3+ states at film surface had an effect on decreasing the electron-hole recombination and the holes oxidized O 2 − anions, which improved the surface hydrophilic. 46,47 The hydrophilic properties of doped and co-doped thin films offered advantages on not only photocatalytic property but also on being self-cleaning surfaces. The dirt can be removed by water sheet due to the hydrophilic surface.…”

Fabrication and Characterization of SiO₂/TiO₂ Nano-Hybrid Particles

“…Among these studies, doping Si in TiO 2 photocatalyst is one effective way to improve the catalyst photoactivity and acidity [4]. Up to now, the morphologies of the prepared SiO 2 /TiO 2 have been mainly core-shell structures [6], films [7][8][9], particles [10,11], nanotubes [12,13] and hollow hybrid spheres [14]. Compared with the other morphologies, particles owned the better activity due to the low density, high specific surface areas, and large surface-to-volume ratios.…”