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ZnO doped with Cr, Mn, Fe, Co, Ni and Cu was prepared by homogeneous hydrolysis of sulfates with urea. The samples were annealed at various temperatures and characterized by X-ray powder diffraction, UV/VIS reflectance spectroscopy, BET (Brunauer-Emmet-Teller) surface area and porosity measurements. The photocatalytic activity of the samples was evaluated by measuring the degradation of an organic dye Reactive Black 5. The morphology of the samples was determined by scanning electron microscopy and atomic force microscopy. For the Cu-doped ZnO sample, EPR spectra were obtained. All samples annealed at 800°C contained hexagonal ZnO. In the VIS region, the best photocatalytic performance had the ZnO samples doped with Cr, Fe and Cu. [ABSTRACT FROM AUTHOR]

The photocatalytic properties of bismuth-modified titania were studied by photobleaching of two aqueous azo dyes solutions (Reactive Black 5 and Acid Orange 7), and by photoinduced decomposition (PID) of acetaldehyde using in situ FTIR spectroscopy. Low bismuth doping concentrations up to 3 at.% is shown to lead to an increased photobleaching rate of both azo dyes solutions. Too high Bi dopant concentrations lead to less developed crystallite nanoparticles and exhibit weaker adsorption capacity. Bismuth doping altered the adsorption kinetics of acetaldehyde resulting in different surface products, and a modified photocatalytic reaction pathway was inferred. [ABSTRACT FROM AUTHOR]

The photocatalytic properties of bismuth-modified titania were studied by photobleaching of two aqueous azo dyes solutions (Reactive Black 5 and Acid Orange 7), and by photoinduced decomposition (PID) of acetaldehyde using in situ FTIR spectroscopy. Low bismuth doping concentrations up to 3 at.% is shown to lead to an increased photobleaching rate of both azo dyes solutions. Too high Bi dopant concentrations lead to less developed crystallite nanoparticles and exhibit weaker adsorption capacity. Bismuth doping altered the adsorption kinetics of acetaldehyde resulting in different surface products, and a modified photocatalytic reaction pathway was inferred. [ABSTRACT FROM AUTHOR]

The nanocomposites of titania coupled with graphene oxide ( GO) and reduced graphene oxide ( rGO), respectively, were prepared by homogeneous hydrolysis with urea. Graphene was obtained by effect of high-intensity cavitation field on natural graphite in the presence of strong aprotic solvents in pressurized ultrasonic reactor. The morphology of TiO2- GO and TiO2- rGO composites was assessed by scanning electron microscopy and atomic force microscopy. The nitrogen adsorption-desorption was used for determination of surface area ( BET) and porosity. Raman and IR spectroscopy were used for qualitative analysis and diffuse reflectance spectroscopy was employed to estimate band-gap energies. Further enhancement of the photocatalytic activity was attained by codoping of composites with noble metals- Au, Pd and Pt. The photocatalytic activity of TiO2- GO and TiO2- rGO were assessed by photocatalytic decomposition of Orange II dye in an aqueous slurry under UV and visible light irradiation. The photocatalytic activity of noble metals codoped samples was determined with decomposition of Reactive Black 5 azo dye. [ABSTRACT FROM AUTHOR]

A novel In3+-doped TiO2 and TiO2/In2S3 nanocomposites for photocatalytic degradation of environmental pollutants and stoichiometric degradation of warfare agents were prepared by a homogeneous hydrolysis with urea and thioacetamide, respectively. The prepared samples series TiInTAA were annealed at 600°C. The prepared samples were characterized by X-ray powder diffraction, IR spectroscopy, Raman spectroscopy, specific surface area (BET) and porosity determination. The method of UV-Vis diffuse reflectance spectroscopy was employed to estimate band-gap energies. The photocatalytic activity (PCA) was tested by degradation of Orange dye, whereas stoichiometric activity was studied by degradation of sulfur mustard. Incorporation of In3+ into titania lattice increases PCA of TiO2 in the visible light and increases stoichiometric decomposition of sulfur mustard against nondoped TiO2 as well. PCA of TiO2/In2S3 composite depends on the optimal ratio of TiO2:In2S3 in composite, while the activity for stoichiometric decomposition of sulfur mustards depends on the content of In2S3 in nanocomposite. [ABSTRACT FROM AUTHOR]