Measured pH and dissolved ferric iron concentration ([Fe(III)diss]) in contact with well-characterized hematite indicated an equilibrium with hematite immediately after synthesis, but [Fe(III)diss] increased with hydration time to be consistent with the predicted solubility of goethite or hydrous ferric oxide (HFO), hydrated analogues of hematite. X-ray diffraction did not detect structural mod...

This paper presents and validates a new paradigm for modeling complex biogeochemical systems using a diagonalized reaction-based approach. The bioreduction kinetics of hematite ( -Fe2O3) by the dissimilatory metal-reducing bacterium (DMRB) Shewanella putrefaciens strain CN32 in the presence of the soluble electron shuttling compound anthraquinone-2,6-disulfonate (AQDS) is used for presentation/...

In this study, we prepared high-stability hematite mesocrystals by a facile route without polymer additives. In particular, the rhombic hematite mesocrystals exhibit excellent lithium insertion behavior compared to the hematite single-crystals.

Introduction. The Thermal Emission Spectrometer (TES) instrument aboard Mars Global Surveyor discovered several isolated deposits of gray, crystalline hematite in Sinus Meridiani, Aram Chaos, and Valles Marineris. A variety of formation mechanisms has been proposed for the martian hematite deposits [1-5], including aqueous and nonaqueous processes. Comparison of the average Sinus Meridiani hema...

Since 2001, there have been two, parallel interpretations of Mars Global Surveyor Thermal Emission Spectrometer (TES) observations of Sinus Meridiani, which are: (1) coarse hematite is the only spectral match; and (2) fine-grained hematite with particles closer than ~wavelength (“fine-intimate hematite”, e.g., coating, ferricrete) is a better match, but coarse hematite is also viable. The TES t...

Polymer concretes (PCs) were created by using varying concentrations of silica sand as aggregate and also hematite, colemanite and a commercial epoxy resin. Hematite is known to exhibit radiation shielding properties. Mechanical performance was evaluated including unit weight, pulse velocity, compressive strength, flexural strength, splitting tensile strength, modulus of elasticity and dynamic ...

Introduction: Meridiani Planum was chosen as the landing site for the Mars Exploration Rover Opportunity partially based on Mars Global Surveyor Thermal Emission Spectrometer data indicating an abundance of hematite [1]. Hematite often forms through processes that involve water, so the site was a promising one to determine whether conditions on Mars were ever suitable for life [1,2]. Opportunit...

Photochemical deposition of Co and Ni based oxygen evolution catalysts on hematite nanorods cathodically shifted the onset potential of photocurrent near to the flat band potential of hematite. A 9.5 fold enhancement in the photocurrent density at 0.86 V vs. RHE compared to the parent hematite photoanode was observed with the Ni-Bi/Fe(2)O(3) photoanode.

The visible light photochemical reactivity of a 50 nm thick α-Fe(2)O(3)(0001) (hematite) film on a SrTiO(3)(111) substrate is compared to the reactivities of bulk hematite and the same film supported by α-Al(2)O(3)(0001). The hematite film supported by SrTiO(3)(111) is far more reactive then the other two cases.

Introduction: Analysis of OMEGA and CRISM spectral data for sulfate-rich Interior Layered Deposits (ILDs) in Valles Marineris has revealed complex assemblages of iron oxides and multiple sulfates [1-7]. We have been developing stratigraphic assemblages to assess the similarities and differences among chasma [3, 5, 7]. Here we present sulfate and iron oxide stratigraphy within the central ILD of...