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Abstract: Anatase (TiO2) thin films were obtained by immersion of glass plates into a titanium sol–gel precursor followed by calcination at 450°C for 3h. The Raman results for the CO2 laser irradiated TiO2 films show that laser radiation is able to promote favorable changes of anatase phase in anatase/rutile mixtures. Nevertheless, the transformation process level depends on laser characteristics and scan speed of the radiation treatment. [Copyright &y& Elsevier]

Abstract: Sol–gel derived rough anatase films without controlled particle sizes were prepared by surfactant templating. The coating sol–gel was obtained by hydrolysis of Ti(OC3H7)4 in ethanol/HNO3 solution. The gel films, prepared by dipping glass substrates in surfactant solutions, were dried after immersion under an atmospheric pressure. The rough films of TiO2 anatase were obtained after calcining at 500°C. The resultant films were transparent, semitransparent or opaque and 136–402nm thick. It was found that the TiO2 films prepared from the sol–gel with surfactant showed a granular nanostructure, and they were composed of regular particles, for example; between 50 and 70nm. The roughness of the films was found to depend on the surfactant concentration in the sol–gel solution and can show a roughness between 0.82 and near of 17nm. The photocatalytic activity of the films for the degradation and mineralization of phenol, an industrial pollutant, in water and under 365nm irradiation was improved by the surfactant modification. Kinetic analysis of degradation and mineralization of phenol in water were employed to evaluate the different TiO2 films under the same experimental conditions. The global photonic efficiency for degradation and mineralization of phenol ξ g, was calculated to facilitate comparison with a TiO2 standard photocatalyst named Degussa P-25. [Copyright &y& Elsevier]

Abstract: Substrate dipping in a composite sol–gel solution was used to prepare both smooth and rough thin films of titanium dioxide (TiO2) on commercial fiberglass. The deposition of a composite film was done in a beaker using a solution of titanium (IV) isopropoxide as the sol–gel precursor and cetyltrimethyl ammonium bromide as the surfactant. In order to establish a correlation between experimental conditions and the titanium oxide produced, as well as the film quality, the calcined samples were characterized using Raman spectroscopy, UV–vis spectrophotometry, scanning electron microscopy and atomic force microscopy. One of the most important results is that a 61-nm TiO2 film was obtained with a short immersion of fiberglass into the sol–gel without surfactant. In other cases, the deposited film consisted of a titanium precursor gel encapsulating micelles of surfactant. The gel films were converted to only the anatase phase by calcining them at 500 °C. The resulting films were crystalline and exhibited a uniform surface topography. In the present paper, it was found that the TiO2 films prepared from the sol–gel with a surfactant showed a granular microstructure, and are composed of irregular particles between 1.5 and 3 μm. Smooth TiO2 films could have useful optical and corrosion-protective properties and, on other hand, roughness on the TiO2 films can enhance the inherent photocatalytic activity. [Copyright &y& Elsevier]

Abstract: Anatase thin films (<200nm in thickness) embedding Degussa P25 TiO2 were prepared by sol–gel method. TiO2-anatase thin films were deposited on a fiberglass substrate and then ground to obtain glass microrods containing the composite films. The film structure was characterized using Raman spectroscopy, atomic absorption and UV–vis spectrophotometry, and atomic force microscopy. The photocatalytic activity of the composite films, calcined at 450°C, and the regeneration of the activity under the same experimental conditions, were assessed using gas chromatography to study the photodegradation of phenol, an industrial pollutant, in water under 365nm irradiation. The film with 15.0wt.% of P25 TiO2 was found to be more photoactive (54ppm of degraded phenol at 6h of illumination) than the other ones. [Copyright &y& Elsevier]