Siderophile elements are depleted in the Earth's mantle, relative to chondritic meteorites, as a result of equilibration with core-forming Fe-rich metal. Measurements of metal-silicate partition coefficients show that mantle depletions of slightly siderophile elements (e.g. Cr, V) must have occurred at more reducing conditions than those inferred from the current mantle FeO content. This implie...

in this work firstly fe2o3 nanoparticles were synthesized via a simple chemical method. properties of the product were examined by x-ray diffraction pattern (xrd), scanning electron microscope (sem) and fourier transform infrared (ft-ir) spectroscopy. vibrating sample magnetometer (vsm) shows nanoparticles exhibit ferromagnetic behavior. to continue some of the 2-naphthol condensed 1,3-oxazinon...

a new type of magnetically-recoverable catalyst was synthesized by the immobilization of h3pw12o40 on the surface of silica-encapsulated -fe2o3 nanoparticles. a series of novel 1,3,5-triaryl pyrazoline derivatives has been synthesized by the reaction of chalcone and phenylhydrazine in the presence of the -fe2o3@sio2-pw12nanoparticles,  in high yields. the structures of compounds obtained were...

A microwave hydrothermal method is developed for the synthesis of iron oxides, α-Fe2O3, β-FeOOH, and the junction of α-Fe2O3-β-FeOOH. This method is absolutely organic-free, and various structures could be obtained simply by changing the use of the iron source and NaOH. The as-prepared sea urchin-like β-FeOOH exhibits excellent catalytic performance for the degradation of methylene blue (MB) in...

While preparation of metal oxide from metal organic frameworks (MOFs) has been widely studied, crystal growth via thermal decomposition of MOFs in a confined space is rarely investigated. We demonstrate a confinement effect on the crystal growth via pyrolysis of MOFs at high temperature. Iron containing MOF (Fe-MIL-88A) was calcined inside a SiO2. The crystalline phase, particle size, morpholog...

ZnO-Fe2O3 mixed oxides and supported gold nanocatalysts were prepared by using coprecipitation and deposition–precipitation methods, respectively. Cinnamaldehyde hydrogenation over various ZnO-Fe2O3 mixed oxides supported gold nanocatalysts have been investigated at 140 ◦C and a hydrogen pressure of 1.0 MPa. The molar ratio of Fe to Zn was found to greatly affect the selective hydrogenation cat...

The process of reductive dissolution of α-Fe2O3, Ba-hexaferrite, α-FeOOH, γ-Fe2O3, γ-FeOOH, and ferrihydrite can be monitored continuously by abrasive stripping voltammetry and chronoamperometry to obtain information about homogeneity of reactivity and about the particle size of the pure phases and mixtures. Phase parameters (rate constant and charge transfer coefficient) and the geometrical fa...

Magnetic nanoparticles are frequently coated with SiO2 to improve their functionality and bio-compatibility in a range of biomedical and polymer nanocomposite applications. In this paper, a scalable flame aerosol technology is used to produce highly dispersible, superparamagnetic iron oxide nanoparticles hermetically coated with silica to retain full magnetization performance. Iron oxide partic...