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potential applications of TiO 2 for solar energy conversion. Titanium dioxide is extensively studied as a photocatalyst for water splitting because of its high photocatalytic activity, robust chemical stability, relatively low production costs, availability

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Abstract  

A simple method for preparing F-doped anatase TiO2 nanoparticles with high visible light photocatalytic activity was developed using TiCl4 and HF as TiO2 and fluorine precursors in HCl solution by a one-step hydrothermal treatment without any organic species. The presence of HF plays an important role in the formation of the F-doped shuttle-like anatase TiO2 nanostructures. XRD analysis showed that the F could prevent the transformation of anatase to rutile in HCl solution. Compared with ordinary TiO2, the F-doped TiO2 nanoparticles synthesized at 180 °C exhibited better photocatalytic activity for the degradation of rhodamine B under visible light irradiation. Possible formation mechanism of F-doped anatase TiO2 under hydrothermal conditions was discussed.

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Journal of Thermal Analysis and Calorimetry
Authors: Mphilisi M. Mahlambi, Ajay K. Mishra, Shivani B. Mishra, Rui W. Krause, Bhekie B. Mamba and Ashok M. Raichur

to play an important role in solving many serious environmental and water pollution problems [ 2 ]. Titanium dioxide (TiO 2 or titania) is a metal oxide semiconductor that has been extensively studied as a photocatalyst. As a photocatalyst

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Green chemistry approach for the synthesis of PbSnO3

An effective photocatalyst for the degradation of dyes under sunlight

Journal of Thermal Analysis and Calorimetry
Authors: A. V. Borhade and Y. R. Baste

radiation and semi-conductor catalysts has a strong potential as it has been widely demonstrated in the recent years [ 10 ]. Visible light-induced photocatalysts have received considerable attention because visible light occupies the main part of solar light

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the preparation of titania photocatalyst was developed. Methods of TG, DTA, ETA, EGA/MS and FTIR made it possible to characterize the thermal behaviour of titania precursors prepared by using H 2 O 2 and HNO 3 , respectively and to recommend optimum

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carried out in search for advanced heterogeneous photocatalysts that can work under visible light. Among the metal oxides, TiO 2 has attracted extensive attention as a promising technique for the photocatalytic decomposition of organic pollutants in water

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Abstract  

A TiO2/monazite photocatalyst was prepared by embedding TiO2 nanoparticles into a monazite substrate surface. TiCl4 hydrolysis/citric acid chelating procedure under acidic conditions were used to synthesize the nanophase TiO2 particles. The anatase TiO2/monazite photocatalyst surface area, morphology, crystalline and elemental concentrations were characterized using Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), X-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Monazite contains a large amount of Ce-, La-, Nd- and Th-PO4 compounds; it has been known as a natural mineral material with minor radioactivity. TiO2-CeO2 composite is a kind of radiation sensitive photocatalyst in which the radiations of thorium nuclides give energy to trigger TiO2 and cerium ions which play an energy absorber with charge separator. The result showed that methylene blue and phenol were spontaneously photocatalytic decomposed by TiO2/monazite composite even in a dark environment. A synergistic effect was also examined with applied exterior UV or 60Co irradiation. A hybrid mechanism is proposed; according by the radioluminescence (RL) from excited Ce ion by γ-radiation soliciting CeO2/TiO2 heterojunction (HJ). This seems to be a possible mechanism to explain this self-activated photo-catalytic behavior.

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Abstract  

To utilize visible light more efficiently in photocatalytic reactions, Bi2O3/CaO photocatalysts were prepared by a mechanical mixing method and characterized by X-ray diffraction (XRD) and UV–vis spectroscopy. UV–vis spectroscopy results showed that the photocatalysts have a wide absorption band in the range of visible light. The photocatalytic activities of obtained Bi2O3, CaO, and Bi2O3/CaO samples were evaluated by methylene blue degradation under visible light irradiation. It was found that the Bi2O3/CaO sample exhibited the highest photocatalytic activity.

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Reaction Kinetics, Mechanisms and Catalysis
Authors: Bo-Hyun Kim, Tae-Hee Lim, Jin-Woong Roh, Sang-Geun Lee, Chang Ju, Seong Park, Seong Hong and Gun Lee

Abstract  

Undoped and Cr-doped Bi12TiO20 (BTO) were prepared and used as photocatalysts for the degradation of formic acid both under visible light and UV irradiation. The effects of the Cr doping on the visible light response and the photocatalytic activity of BTO were investigated. The prepared catalysts were characterized by using XRD, XPS, UV–Vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy. The doping of Bi12TiO20 with low concentration of Cr leads to noticeable increase in visible light absorption and decrease in the recombination rate of photo-generated electrons and holes. As a result, the Cr-doped BTO showed a higher photocatalytic activity for the degradation of formic acid both under visible light and UV irradiation, as compared with undoped BTO.

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Abstract  

Gd2O3/Ag3VO4 photocatalysts are synthesized through the impregnation method and characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV–vis diffuse reflectance spectra (DRS). It is shown that Gd3+ is dispersed on the surface of Ag3VO4 in the form of Gd2O3. The DRS analysis indicates that the ability of visible-light absorption of Gd2O3/Ag3VO4 catalysts is enhanced greatly. The photocatalytic activities of the samples are evaluated by degradation of Rhodamine B dye under UV and visible-light irradiation, respectively. The experimental results show that the role of Gd2O3 content has a significant impact on the photocatalytic activities of the samples. The mechanism of enhanced photocatalytic activity after the Gd introduction is discussed.

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