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    First principles study of oxygen adsorption on nickel-doped graphite

    , Article Molecular Physics ; Volume 110, Issue 13 , Feb , 2012 , Pages 1437-1445 ; 00268976 (ISSN) Nahali, M ; Gobal, F ; Sharif University of Technology
    Density functional theory is used in a spin-polarized plane wave pseudopotential implementation to investigate molecular oxygen adsorption and dissociation on graphite and nickel-doped graphite surfaces. Molecular oxygen physisorbs on graphite surface retaining its magnetic property. The calculated adsorption energy is consistent with the experimental value of 0.1eV. It is found that substituting a carbon atom of the graphite surface by a single doping nickel atom (2.8% content) makes the surface active for oxygen chemisorption. It is found that the molecular oxygen never adsorbs on doping nickel atom while it adsorbs and dissociates spontaneously into atomic oxygens on the carbon atoms... 

    Aqueous phase reforming of glycerol using highly active and stable Pt0.05CexZr0.95-xO2 ternary solid solution catalysts

    , Article Applied Catalysis A: General ; Volume 523 , 2016 , Pages 230-240 ; 0926860X (ISSN) Larimi, A. S ; Kazemeini, M ; Khorasheh, F ; Sharif University of Technology
    The aqueous phase reforming (APR) of glycerol is an attractive yet challenging pathway to convert abundant biomass into value added hydrogen. Pt catalysts have received attention due to their ability to produce hydrogen-rich gas under APR conditions. In this work, the conversion of glycerol into hydrogen is demonstrated using Pt0.05CexZr0.95-xO2 (x = 0, 0.29, 0.475, 0.66 and 0.95) solid solution catalysts. Both characteristic (XRD, BET, H2-TPR, CO-chemisorption, TEM and XPS) and reactivity measurements were used to investigate the activity of the catalysts. Results indicated that reactivity depended on the Ce/Zr ratio, which in turn affected the Pt oxidation state, active metal dispersion... 

    Nanomechanical properties of TiO2 granular thin films

    , Article ACS Applied Materials and Interfaces ; Volume 2, Issue 9 , 2010 , Pages 2629-2636 ; 19448244 (ISSN) Yaghoubi, H ; Taghavinia, N ; Keshavarz Alamdari, E ; Volinsky, A.A ; Sharif University of Technology
    Post-deposition annealing effects on nanomechanical properties of granular TiO2 films on soda-lime glass substrates were studied. In particular, the effects of Na diffusion on the films' mechanical properties were examined. TiO2 photocatalyst films, 330 nm thick, were prepared by dip-coating using a TiO2 sol, and were annealed between 100 °C and 500 °C. Film's morphology, physical and nanomechanical properties were characterized by atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, differential thermo-gravimetric analysis, and nanoindentation. Contrary to expectations, the maximum film hardness was achieved for 300°C annealing, with a value of 0.69 ± 0.05 GPa.... 

    Optimal design and characterization of superparamagnetic iron oxide nanoparticles coated with polyvinyl alcohol for targeted delivery and imaging

    , Article Journal of Physical Chemistry B ; Volume 112, Issue 46 , 2008 , Pages 14470-14481 ; 15206106 (ISSN) Mahmoudi, M ; Simchi, A ; Imani, M ; Milani, A. S ; Stroeve, P ; Sharif University of Technology
    American Chemical Society  2008
    Superparamagnetic iron oxide nanoparticles (SPION) with narrow size distribution and stabilized by polyvinyl alcohol (PVA) were synthesized. The particles were prepared by a coprecipitation technique using ferric and ferrous salts with a molar Fe3+/Fe2+ ratio of 2. Using a design of experiments (DOE) approach, the effect of different synthesis parameters (stirring rate and base molarity) on the structure, morphology, saturation magnetization, purity, size, and size distribution of the synthesized magnetite nanoparticles was studied by various analysis techniques including X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) with differential scanning calorimetry (DSC)...