Yazar "Gubbuk, I. Hilal" seçeneğine göre listele

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    Catalytic degradation of organic dye using reduced graphene oxide-polyoxometalate nanocomposite
    (ELSEVIER SCIENCE SA, 2017) Ucar, Asuman; Findik, Mukerrem; Gubbuk, I. Hilal; Kocak, Nuriye; Bingol, Haluk
    Silicotungstic acid (SiW) decorated reduced graphene oxide (rGO) nanocomposite (rGO-SiW) has been prepared and evaluated as a heterogeneous nanocatalyst for the degradation reactions of methylene blue (MB) and rhodamine B (RhB). The structural and morphological properties of rGO-SiW nanocomposite were investigated by various techniques such as Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), Atomic force microscopy (AFM) and Scanning electron microscope (SEM), which revealed the homogeneous and noncovalent anchoring of SiW nanoparticles on rGO sheets. The catalytic activity of rGO-SiW nanocomposite on the degradations of MB and RhB has been monitored using UV-visible absorption spectrometry in the presence of NaBH4 as the reducing agent at room temperature in water. The reduction reactions followed pseudo-first order kinetics and degradation were achieved in 34 min for MB and 81 min for RhB using rGO-SiW as catalysts. (C) 2017 Elsevier B.V. All rights reserved.
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    Öğe
    A new Keggin-type polyoxometalate catalyst for degradation of aqueous organic contaminants
    (ELSEVIER, 2017) Olgun, Asim; Colak, Alper Tolga; Gubbuk, I. Hilal; Sahin, Onur; Kanar, Ebru
    In this study, a new polyoxometalate,K-16[Ni(H2O)(6)](2)[BW12O40]4(center dot)48H(2)O (1) was synthesized at room temperature and characterized by X-ray single crystal diffractions, elemental analyses, IR spectra, and thermo gravimetric analyses (TGA). Crystal structure analysis reveals that compound 1 exhibits a supramolecular structure containing one Keggin-type [BW12O40](4) heteropoly anion. The catalytic properties of this molecule for the degradation of Methyl red (MR), Rhodamine B (RhB), Methyl orange (MO) and Congo red (CR) were investigated. The results show that the compound 1 is a promising catalyst candidate for dye degradation. (C) 2016 Elsevier B.V. All rights reserved.