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Abstract: SnO2/TiO2 composite films were fabricated on transparent electro-conductive glass substrates (F-doped SnO2-coated glass:FTO glass) via an electrophoretic deposition (EPD) method using Degussa P25 as raw materials, and were further characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), UV–vis diffuse reflectance spectra and Photoluminescence spectra (PL). XRD and XPS results confirmed that the films were composed of TiO2 and SnO2. FESEM images indicated that the as-prepared TiO2 films had roughness surfaces, which consisted of nano-sized particles. The effects of calcination temperatures on the surface morphology, microstructures and photocatalytic activity of SnO2/TiO2 composite films were further investigated. All the prepared SnO2/TiO2 composite films exhibited high photocatalytic activities for photocatalytic decolorization of Rhodamine-B aqueous solution. At 400°C, the SnO2/TiO2 composite films showed the highest photocatalytic activity due to synergetic effects of low sodium content, good crystallization, appropriate phase composition and slower recombination rate of photogenerated charge carriers. [Copyright &y& Elsevier]

Abstract: Highly photoactive nanocrystalline mesoporous Fe-doped TiO2 powders were prepared by the ultrasonic-induced hydrolysis reaction of tetrabutyl titanate (Ti(OC4H9)4) in a ferric nitrate aqueous solution (pH 5) without using any templates or surfactants. The as-prepared samples were characterized by thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), N2 adsorption–desorption measurements, UV–visible adsorbance spectra (UV–vis) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities were evaluated by the photocatalytic oxidation of acetone in air. The results showed that all the Fe-doped TiO2 samples prepared by ultrasonic methods were mesoporous nanocrystalline. A small amount of Fe3+ ions in TiO2 powders could obviously enhance their photocatalytic activity. The photocatalytic activity of Fe-doped TiO2 powders prepared by this method and calcined at 400°C exceeded that of Degussa P25 (P25) by a factor of more than two times at an optimal atomic ratio of Fe to Ti of 0.25. The high activities of the Fe-doped TiO2 powders could be attributed to the results of the synergetic effects of Fe-doping, large BET specific surface area and small crystallite size. [Copyright &y& Elsevier]

Abstract: Ag@TiO2 core–shell nanocomposite nanowires were synthesized via a vapor-thermal method using Ag nanowires as templates and tetrabutyl titanate (TBOT) as precursors at 150°C for 10h. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption–desorption isotherms. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic decolorization of Rhodamine B (RhB) aqueous solution at ambient temperature under UV-light irradiation. The results show that the Ag@TiO2 core–shell nanowires exhibit highly efficient and recyclable photocatalytic activity for the degradation of RhB aqueous solution. Moreover, in contrast to the discrete nanoparticles, the Ag@TiO2 nanowires can be readily separated from the treated solution by natural settlement after photocatalytic reaction. [Copyright &y& Elsevier]

Abstract: Ni(OH)2 and NiO nanosheets with hierarchical porous structures were synthesized by a simple chemical precipitation method using nickel chloride as precursors and urea as precipitating agent. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and nitrogen adsorption–desorption isotherms. Adsorption of Congo red (CR) onto the as-prepared samples from aqueous solutions was investigated and discussed. The pore structure analyses indicate that Ni(OH)2 and NiO nanosheets are composed of at least three levels of hierarchical porous organization: small mesopores (ca. 3–5nm), large mesopores (ca. 10–50nm) and macropores (100–500nm). The equilibrium adsorption data of CR on the as-prepared samples were analyzed by Langmuir and Freundlich models, suggesting that the Langmuir model provides the better correlation of the experimental data. The adsorption capacities for removal of CR was determined using the Langmuir equation and found to be 82.9, 151.7 and 39.7mg/g for Ni(OH)2 nanosheets, NiO nanosheets and NiO nanoparticles, respectively. Adsorption data were modeled using the pseudo-first-order, pseudo-second-order and intra-particle diffusion kinetics equations. The results indicate that pseudo-second-order kinetic equation and intra-particle diffusion model can better describe the adsorption kinetics. The as-prepared Ni(OH)2 and NiO nanosheets are found to be effective adsorbents for the removal of Congo red pollutant from wastewater as a result of their unique hierarchical porous structures and high specific surface areas. [ABSTRACT FROM AUTHOR]

SnO2/TiO2 composite films were fabricated on transparent electro-conductive glass substrates (F-doped SnO2-coated glass:FTO glass) via an electrophoretic deposition (EPD) method using Degussa P25 as raw materials, and were further characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), UV-vis diffuse reflectance spectra and Photoluminescence spectra (PL). XRD and XPS results confirmed that the films were composed of TiO2 and SnO2. FESEM images indicated that the as-prepared TiO2 films had roughness surfaces, which consisted of nano-sized particles. The effects of calcination temperatures on the surface morphology, microstructures and photocatalytic activity of SnO2/TiO2 composite films were further investigated. All the prepared SnO2/TiO2 composite films exhibited high photocatalytic activities for photocatalytic decolorization of Rhodamine-B aqueous solution. At 400 degrees C, the SnO2/TiO2 composite films showed the highest photocatalytic activity due to synergetic effects of low sodium content, good crystallization, appropriate phase composition and slower recombination rate of photogenerated charge carriers.