Introduction. Lane et al. [1] and Christensen et al. [2] conclude that the 1996 Global Surveyor Thermal Emission Spectrometer (TES, ~1700–200 cm) spectra of regions in Sinus Meridiani match only coarsely particulate hematite. Here we show spectra of hematite coatings that match the TES signatures. The coating option is important because (1) hematite coatings can require little water to form, wh...

The study has investigated the feasibility of using siderite-coated quartz sand and/or hematite-coated quartz sand columns for removing As from water. Arsenic-spiked tap water and synthetic As solution with As concentrations from 200 to 500 mug/L were used for the experiments. Since three coating methods employed to prepare siderite-coated quartz sand and hematite-coated quartz sand had no sign...

-The formation of hematite from amorphous Fe(III)hydroxide in aqueous systems at pH 6 and 70~ both with and without oxalate, was followed by kinetic measurements, electron microscopy, i.r. spectroscopy and thermal analysis. In the absence of oxalate, small amorphous particles coalesce into aggregates which eventually become single crystals of hematite. When oxalate is present, crystal growth is...

The reaction between dissolved sulfide and synthetic iron (oxyhydr)oxide minerals was studied in artificial seawater and 0.1 M NaCl at pH 7.5 and 25°C. Electron transfer between surface-complexed sulfide and solid phase Fe(III) results in the oxidation of dissolved sulfide to elemental sulfur, and the subsequent dissolution of the surface-reduced Fe. Sulfide oxidation and Fe(II) dissolution kin...

The onset potential is an important parameter that affects the water oxidation performance of photoanodes. Herein, we investigated the behavior of the photocurrent onset potential of hematite (α-Fe2O3) photoanodes by incorporating Sn(4+) cations via external (surface overlayer) or self (underlying FTO substrate) doping. The α-Fe2O3/FTO photoanodes fabricated at both low (550 °C) and high (800 °...

[1] Ground-penetrating radar (GPR) has the potential to image the Martian subsurface to give geological context to drilling targets, investigate stratigraphy, and locate subsurface water. GPR depth of penetration depends strongly on the electromagnetic (EM) properties (complex dielectric permittivity, complex magnetic permeability, and DC resistivity) of the subsurface. These EM properties in t...

In photoelectrochemical cells, sunlight may be converted into chemical energy by splitting water into hydrogen and oxygen molecules. Hematite (α-Fe(2)O(3)) is a promising photoanode material for the water oxidation component of this process. Numerous research groups have attempted to improve hematite's photocatalytic efficiency despite a lack of foundational knowledge regarding its surface reac...