We present measurements of the complete scattering matrix as a function of the scattering angle of randomly oriented irregular hematite and rutile particles. The measurements were made at a wavelength of 632.8 nm in the scattering angle range from 5–174 degrees. Apart from their astronomical interest, these two samples are extremely interesting from a theoretical point of view, because they bot...

Using extended X-ray absorption fine structure (EXAFS) and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) measurements, we examined the sorption of Pb(II) to hematite in the presence of malonic acid. Pb L(III)-edge EXAFS measurements performed in the presence of malonate indicate the presence of both Fe and C neighbors, suggesting that a major fraction of surface-bound malon...

Herein, we demonstrate that an electrochemical surface treatment of Fe foil with simple pulse reverse electrodeposition (PRED) prior to thermal oxidation can substantially enhance the photoelectrochemical (PEC) stability and water splitting performance of Fe2O3/Fe photoanodes. Comprehensive structural (XRD, FESEM, and HRTEM), compositional (XPS depth profiling), and electrochemical (EIS and Mot...

The aim of this study was to examine the catalyzed decomposition of hydrogen peroxide and 2-chlorophenol (2-CP) in the presence of iron oxides. Granular ferrihydrite, goethite, and hematite were selected as catalysts in this study. 2-CP was used as the model compound because it is a typical toxic compound and has not been investigated in the catalytic decomposition by iron oxides. The catalytic...

The effect of the shell thickness and density on the magnetic properties of composite colloidal particles consisting of a hematite (alpha-Fe(2)O(3)) core and an yttrium oxide (Y(2)O(3)) layer is described. Pure iron oxide colloidal spheres show two clearly different trends of variation of their magnetic susceptibility, chi(m), with temperature. Below T(M) approximately 220 K, chi(m) shows a sli...

The colloidal dimer particles are templated from sacrificial α-Fe2O3 (hematite) core particles prepared via aging of a condensed Fe(OH)3 gel as described in [1]. In a typical synthesis, 50 mL of FeCl3 (2.0 M) is mixed with 45 mL of NaOH (6.0 M) and 5 mL of the shapemodifier, Na2SO4 (0.6 M), before being placed in an oven set at 100°C for 8 days. To make the nonmagnetic particles investigated in...

The speciation and fate of neptunium as Np(V)O2(+) during the crystallization of ferrihydrite to hematite and goethite was explored in a range of systems. Adsorption of NpO2(+) to iron(III) (oxyhydr)oxide phases was reversible and, for ferrihydrite, occurred through the formation of mononuclear bidentate surface complexes. By contrast, chemical extractions and X-ray absorption spectroscopy (XAS...

Rhombohedral single crystallites of hematite (iron oxide, R-Fe2O3) in the size range of 20-200 nm have been synthesized by forced hydrolysis in water. The optical Rayleigh scattering and AFM topography of individual crystallites have been recorded on an inverted microscope based apparatus. Individual crystallites show narrow Mie “optical cavity” resonances across the visible spectrum as the par...