Search

Mesoporous TiO2was synthesized by sol-gel method and mechanically mixed with functionalized multiwall carbon nanotubes which decorated by different amount of Ag. Nanocomposite was characterized by X-ray Diffraction, Scanning Electron Microscopy/Transmission Electron Microscopy, Brunauer–Emmett–Teller, Fourier Transform Infrared Spectroscopy, Atomic Absorption Spectroscopy, UV–Visible Diffuse Reflectance Spectroscopy, and UV–Vis Absorption Spectroscopy. The photoactivity of nanocomposite containing mesoporous TiO2, multiwall carbon nanotubes (MWCNT), and Ag was evaluated by the degradation of methyl orange in aqueous solution under UV irradiation. Results showed that the MWCNT that decorated with the 15.5% of Ag facilitates the photocatalytic activity of mesoporous TiO2. [ABSTRACT FROM PUBLISHER]

GR–TiO2nanocomposite was prepared by simple chemical method using graphene oxide and titanium isopropoxide (Ti [OCH (CH3)2]4) precursors. The crystalline nature of the composite was characterised by powder X-ray diffraction and the intercalation was explained by Raman spectroscopy. The morphology of the composite was analysed by field emission scanning electron microscopy. The elemental and quantitative measurement of the composite was determined by electron dispersive spectroscopy. The shape and size of the particle was measured by transmission electron spectroscopy and high resolution spectroscopy. The surface area and elemental composition of the composite was studied by using Brunauer–Emmett–Teller (BET) method and X-ray photoelectron spectroscopy. Photo-generated electrons were studied by photoluminescence spectra. The photocatalytic activity of nanocomposite was investigated by the degradation of Rhodamine-B (Rh-B) in an aqueous solution under solar light irradiation. The GR–TiO2demonstrates photocatalytic activity in the degradation with a removal rate of 98% under solar light irradiation as compared with pure TiO2(42%), graphite oxide (19%), and mechanical mixture GR + TiO2(60%) due to the increased light absorption intensity and reduction of electron–hole pair recombination with the intercalation of graphene and TiO2. The results indicated that the GR–TiO2could be used as a catalyst to degrade Rh-B from coloured wastewater. [ABSTRACT FROM PUBLISHER]

The photocatalytic degradation of acephate was investigated using Ce-doped TiO2(TiO2/Ce) hydrosol. In contrast to previous research conducted under artificial light in the laboratory, this study investigated the decomposition of acephate in a field trial. The results show that acephate can be efficiently degraded by the TiO2/Ce system under natural field conditions; the degradation efficiency was affected by the dosage of the photocatalyst and acephate. The optimum dosage of TiO2/Ce was 2400 g a.i.ha−1, and the photodegradation efficiency of acephate reached 93.5% after 20 h at an acephate dosage of 675 g a.i.ha−1. Ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) analysis detected and identified four degradation products—methamidophos, phosphorothioic acid O,O,S-trimethyl ester, S-methyl methanethiosulfonate and phosphorous acid—that were formed during the TiO2/Ce photodegradation of acephate. Based on the structural identification of the degradation products, a probable photodegradation pathway was proposed, and the first decomposition step may be the cleavage of the C‒N bond of acephate. Subsequently, the P‒S and P‒O bonds may be oxidized gradually or simultaneously to complete the mineralization. [ABSTRACT FROM AUTHOR]

Tungsten and tungsten-carbon doped titania particles were successfully synthesised by a simple solvothermal method using WCl6 as W source and titanium tetra-n-butoxide/ethanol as C source. With the incorporation of W in TiO2 lattice, the near infrared absorption property of W-TiO2 samples was strongly promoted. Furthermore, the visible light absorption capability of TiO2 based samples was also greatly affected by codoping C in W-TiO2. More importantly, the C-W codoped TiO2 samples presented excellent continuous toxic NO gas destruction ability much superior to those of undoped TiO2, solely C and W doped TiO2 as well as commercial P25 titania under the irradiation of UV and visible lights. The near infrared absorption performance and photocatalytic activity of TiO2 based products could be effectively controlled by W doping and C-W codoping, which probably have a promising application in the field of environmental protection and near infrared light shielding. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the optimal conditions for the treatment of chromate [Cr(VI)]- contaminated water by UV photocatalysis using synthesized TiO2-coated silica granules (φ 1.7-4.0 mm) containing 12.4% of TiO2 in a batch method. The effect of the volume of the solution on Cr(VI) removal was investigated in the photocatalysis process by using 10 g of TiO2-coated silica granules in water samples with a constant initial Cr(VI) concentration of 5 mg L- 1. In a 10-mL solution, Cr(VI) concentrations were observed to decrease below the detection limit (< 0.05 mg L- 1) in 300 min. Furthermore, Cr(VI) concentrations gradually decreased with time in other solutions with larger volumes. The capacity of the UV photocatalysis process to remove Cr(VI) using 10 g of TiO2-coated granules did not fluctuate with the solution volume for samples with a constant initial Cr(VI) concentration. The lower the initial pH of the solution, the greater was the amount of Cr(VI) removed from the solution. The addition of chloride ions to the solutions accelerated the removal of Cr(VI) by UV photocatalysis. Ten grams of TiO2-coated silica granules were repeatedly used to the 300-min treatment of the Cr(VI) solution (10 mL, 6 mg L-1) till seven cycles. After four cycles of UV photocatalysis, Cr(VI) was completely removed from all the solutions. After the fifth cycle, the Cr(VI) removal capacity of the UV photocatalysis process decreased with the repeated use of the catalyst. [ABSTRACT FROM AUTHOR]