Photoinduced hydroxyl radical and photocatalytic activity of samarium-doped TiO nanocrystalline. J Hazard Mater

School of Resources Processing and Bioengineering, Central South University, Changsha 410083, China.
Journal of Hazardous Materials (Impact Factor: 4.33). 02/2008; 150(1):62-7. DOI: 10.1016/j.jhazmat.2007.04.045
Source: PubMed

ABSTRACT Sm(3+)-doped TiO(2) nanocrystalline has been prepared by sol-gel auto-combustion technique and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, and also UV-vis diffuse reflectance spectroscopy (DRS). These Sm(3+)-doped TiO(2) samples were tested for methylene blue (MB) decomposition and *OH radical formation. The analysis of *OH radical formation on the sample surface under UV irradiation was performed by fluorescence technique with using terephthalic acid, which readily reacted with *OH radical to produce highly fluorescent product, 2-hydroxyterephthalic acid. It was observed that the presence of Sm(3+) ion as a dopant significantly enhanced the photocatalytic activity for MB degradation under UV light irradiation because both the larger specific surface area and the greater the formation rate of *OH radical were simultaneously obtained for Sm(3+)-doped TiO(2) nanocrystalline. The adsorption experimental demonstrated that Sm(3+)-TiO(2) had a higher MB adsorption capacity than undoped TiO(2) and the adsorption capacity of MB increased with the increase of samarium ion content. The results also indicated that the greater the formation rate of *OH radical was, the higher photocatalytic activity was achieved. In this study, the optimum amount of Sm(3+) doping was 0.5 mol%, at which the recombination of photo-induced electrons and holes could be effectively inhibited, the highest formation rate of *OH radicals was, and thereby the highest photocatalytic activity was achieved.

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Available from: Zhichun Si, Aug 24, 2015
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    • "The lanthanide ions with 4f electron configurations into TiO 2 lattice can act as an electron reservoir to trap electrons and significantly increase the separation rate of generated electron–hole pairs, resulting in the improvement of the catalytic activity [27] [28] [29]. On the other hand, lanthanide ions doping can enhance the light sensitivity of catalyst and provide a means to concentrate the organic pollutant at the catalyst surface [30] [31]. "
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    Ultrasonics Sonochemistry 02/2015; 26:281–292. DOI:10.1016/j.ultsonch.2015.02.001 · 4.32 Impact Factor
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    • "The enhanced production of HCHO using P25-500 and other catalytic reaction under direct sunlight irradiation was confirmed by hydroxyl radical ( • OH) determination during the course of the reaction using fluorescence technique with terephthalic acid as a probe molecule (Ishibashi et al. 2000; Yu et al. 2009; Xiao et al. 2008). The result revealed that (Fig. 12a– e), the fluorescence intensity at 425 nm is increased with increase in the direct sunlight irradiation time for all the catalytic reaction. "
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