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In this paper, we report on the preparation and study of Mg doped Co-Zn Nano-ferrites. Properties of nano ferrites strongly depend upon synthesis methods and conditions. To get better properties of prepared samples, Co-Zn ferrite nano particles having composition Co0.5Zn0.5-xMgxFe2O4 (with x= 0.1, 0.2, 0.3, 0.4, 0.5) were prepared by using simplified sol-gel process. The cations in synthesized composition of spinel ferrites occupy appropriate lattice sites and results in exchange coupling. The crystallite size of the specimen increased by sintering the samples at 700 °C for 3 hours. The dielectric loss and dielectric constant of sintered samples were increased with the Mg doping concentration. Saturation magnetization was decreased while coercivity increased with Mg doping concentration. [ABSTRACT FROM AUTHOR]

Nanoparticles of titanium dioxide (TiO2), co-doped with carbon (C) and yttrium (Y) were prepared by hydrothermal method using titanium tetraisopropoxide (TTIP), glucose and Y2O3 as precursors. The prepared samples calcined at 5000C were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD results showed anatase phase of TiO2 nanoparticles and crystallite size of TiO2 nanoparticles were decreased with doping of C and Y. The decrease of particle size was also confirmed by TEM. FTIR measurements demonstrate the identification of functional groups present at the surface of TiO2. Absorption spectra showed a red shift of absorption band edge in visible light region due to synergistic effects of Y and C. The photocatalytic activity measurements were performed for the degradation of methyl orange (MO) dye under visible light illumination. The results obtained demonstrated that photocatalytic activity was enhanced due to doping and codoping of C and Y. It is expected that this work will give new insights in the developments of novel visible light active photocatalysts for environmental issues. [ABSTRACT FROM AUTHOR]

A novel Ce-TiO2/graphene composite photocatalyst was synthesized by method of hydrothermal. The synthesized catalysts were analyzed by TEM, XRD, and XPS, DRS and PL spectroscopy, TGA and GC-MS. The results demonstrate that Ce-TiO2/graphenecatalysts showed enhanced absorption of light energy in visible region, also inhibited the recombination of charge carrier due to cooperative effects of graphene and cerium. The photocatalytic action of prepared catalysts was investigated by degradation of dye methylene blue (MB) under solar irradiation. The GC-MS results shows that the dye Methylene Blue has completely mineralized to CO2 and H2O. The synthesized composites of Ce-TiO2/graphene showed enhanced catalytic activity for MB degradation compared to Ce-TiO2 and pure TiO2. The improved photocatalytic degradation of MB can be attributed to excellent properties of graphene. [ABSTRACT FROM AUTHOR]

Mg-Al system and 2mol% Ni additive nano catalyst in the particle size range of 30-45 nm were synthesized at relatively low temperature by thermal decomposition of coprecipitated [Mg(Bipy)2]Cl2, [Al(Bipy)2]Cl4 and [Ni(Bipy)3]Cl2 in an inert ambient of dry argon gas. The silvery black Mg-Al alloy and dark black Ni nanoparticles were found to be air-stable. Afterwards 2mol% Ni was added in Mg-Al system by high energy ball milling. These nano alloys were characterized by Transmission electron microscopy (TEM) Scanning electron microscopy (SEM) and X-rays diffraction (XRD) for compositional and structural analysis. Hydrogen absorption measurements were carried out using seivert'z type apparatus. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch (FT) synthesis in fixed bed micro reactor (high pressure reaction cell) was studied over different wt% Co supported Na-montmorillonite (NaMMT) and Al-pillared montmorillonite (AlMMT) catalysts. The synthesized catalysts were characterized by XRD, TPR, NH3-TPD, TGA, BET and SEM techniques. FT reaction was carried out at temperature 225, 260 and 275°C and pressure of 1, 5, and 10 bar. Co supported NaMMT catalysts showed very lower CO-conversion along with increase methane selectivity while AlMMT supported Co catalysts gave higher CO-conversion and lower methane selectivity. With increase in reaction temperature from 225°C to 275°C methane selectivity and CO-conversion increased and the selectivity towards C5+ hydrocarbons decreased. Decrease in methane selectivity while increase in C5+ hydrocarbons and COconversion was observed when the pressure was increased to 5 and 10 bar. [ABSTRACT FROM AUTHOR]