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    Item type:Publication,
    Effect of cobalt dopant on structural and optical properties of co-precipitated TiO2 nanopowders
    (2016-01-01)
    Junlabhut, Prasopporn
    ;
    Wattanawikkam, Chakkaphan
    ;
    Phoohinkong, Weerachon
    ;
    Mekprasart, Wanichaya
    ;
    Pecharapa, Wisanu
    The effects of cobalt (Co) addition on structural and optical properties of TiO<inf>2</inf> nanopowders have been investigated. A co-precipitation method was employed to synthesize TiO<inf>2</inf> nanoparticles with various Co additives from 0-10 mol% using tetrabutyl titanate and Cobalt (II) nitrate hexahydrate as starting precursors for Ti and Co source, respectively. The crystallinity of Co-doped TiO<inf>2</inf> nanopowders is heightened by calcination process. The crystal structure, phase formation and the corresponding functional groups of Co-doped TiO2 were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscope (SEM) was taken to observe their morphologies. The chemical compositions of Co additive into TiO<inf>2</inf> matrix are confirmed by EDAX. Their optical properties were investigated by diffuse reflectance spectroscopy. Diffuse reflectance spectra of samples exhibit the increasing absorption in visible region with an increasing Co content. The overall characterization results indicated that the crystallinity and optical properties of TiO<inf>2</inf> nanoparticles are significantly affected by Co dopant.
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    Item type:Publication,
    Characterization of ZnO:Sn nanopowders synthesized by co-precipitation method
    (2014-01-01)
    Junlabhut, Prasopporn
    ;
    Mekprasart, Wanichaya
    ;
    Noonuruk, Russameeruk
    ;
    Chongsri, Krisana
    ;
    Pecharapa, Wisanu
    ZnO:Sn nanopowders were synthesized by co-precipitation method using zinc acetate dihydrate and tin (IV) chloride hexahydrate as a precursors. Co-precipitate of ZnO:Sn nanopowders with various Sn additive 0-50 %wt were obtained by calcination process at 500 °C. The corresponding functional groups and chemical bonding of the samples were investigated by Fourier Transform Infrared Spectroscopy (FTIR). The effects of Sn addition on structural and morphological properties of ZnO:Sn nanopowders have been investigated by X-ray diffraction (XRD), Raman Spectroscopy (Raman) and Scanning electron microscopy (SEM). The chemical bonding of Zn-O, Sn-O and Sn-OH in ZnO:Sn nanopowders were observed by FTIR results. The phase formation of this coumpound was observed with increasing Sn content with calcined at 500 °C. These results indicate that the crystallinity and structural of ZnO nanopowders are significantly affected by Sn dopant.
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    Item type:Publication,
    Study of antifungal activities of CuO/ZnO nanocomposites synthesized by co-precipitation method
    (2013-10-29)
    Phiwdang, Kankanit
    ;
    Phensaijai, Mongkol
    ;
    Pecharapa, Wisanu
    In this work, series of CuO/ZnO functional nanocomposites were synthesized through co-precipitation method using CuCl<inf>2</inf>·H<inf>2</inf>O and ZnCl<inf>2</inf> as starting materials with various molar ratio of copper:zinc, followed by annealing process at 600°C for 2 hours to obtain CuO/ZnO nanocomposites. The structures of the composites were analyzed using X-ray diffraction and field emission scanning electron microscopy. For XRD result, diffraction peaks of the composites reveal the well-crystalline characteristic indicating the mixture phase of CuO and ZnO. SEM results show different morphologies of CuO, ZnO and Cu-Zn oxide nanocomposites appearing in quasi spherical structure.The composites were used for antifungal activity via agar disk diffusion method. It is found that the composite with certain ratio of Cu:Zn exhibits superiority in partial inhibition of strain AspergillusflavusTrichoderma comparing to either pure CuO or ZnO. © (2013) Trans Tech Publications, Switzerland.
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    Item type:Publication,
    Structure properties of as-synthesized Cu-doped ZnO nanopowder synthesized by co-precipitation method
    (2013-01-01)
    Thaweesaeng, Napaporn
    ;
    Supankit, Sineenart
    ;
    Techidheera, Wicharn
    ;
    Pecharapa, Wisanu
    pure ZnO and Cu - doped ZnO nanopowders (1, 2, 3, 4 and 5 wt% Cu) were synthesized by coprecipitation method without further post-heat treatment. The as-synthesized powders were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Raman spectroscopy. The XRD results represented as-synthesized Cu-doped ZnO nanopowders in hexagonal wurtzite structure and SEM images demonstrated the shape and size of as-prepared samples. In addition, Raman spectra confirm space group of ZnO. All results indicated significant influence of Cu doping on relevant structural properties of ZnO. © 2013 The Authors.