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 °...

The Eocene Huber Formation, exposed in the CFI Hall mine south of Irwinton, in Wilkinson County, Georgia, displays colored zones that are a consequence of an oxidative weathering front. These zones vary from very light gray (gray) to pinkish white (pink) to very pale yellow (cream) (Munsell N8, 5YR 8/2 and 2.5Y 8/2, respectively) with increasing degree of oxidation. A representative sample from...

The solubility of andradite garnet was determined at 800 °C and 10 kbar in a solution of 10 mol% NaCl and 90 mol% H2O. Experiments were syntheses carried out with high-purity natural wollastonite, reagent hematite or natural specular hematite containing ~1 wt% TiO2, and fluid. All experiments were performed with Mn2O3-Mn3O4 or Fe2O3-Fe3O4 oxygen buffers in a piston-cylinder apparatus with NaCl ...

An elliptically polarized light scattering (EPLS) technique for the size and shape characterization of ellipsoidal hematite particles is presented. The hematite particles are synthesized by aging aqueous FeCl(3) or Fe(NO(3))(3) solutions at 100 degrees C. Different reaction conditions create particles of aspect ratios between 1 (spherical) and 8 (elongated). Cross-sectional diameter and aspect ...

Mineralogical transformations of 2-line ferrihydrite were studied under oxic and Fe-reducing conditions to establish the role, if any, of 6-line ferrihydrite (“well” organized ferrihydrite) in the reaction pathway and as a final product. In oxic experiments, concentrated suspensions (0.42 mol/L Fe in 0.1 mol/L NaClO4) of freshly synthesized 2-line ferrihydrite, with and without 3% Ni, were aged...

in the past decade, magnetic nanomaterials have attracted much attention due to their physical properties and technological applications. in this work, α-fe2o3 nanoparticles were first synthesized via a simple co-precipitation method using iron chloride hexahydrate (fecl3.6h2o) as precursor and ammonia solution as precipitator. the samples were then characterized by high resolution transmission...

The processes responsible for the transformation of banded iron formations to hard high-grade hematite ore, and their timing, remain poorly understood despite many recent advances. The paleomagnetic method allows for the estimation of ore genesis timing as a complement to other techniques. The effectiveness of the paleomagnetic method at dating, and testing proposed models for, the genesis of h...

Hematite (α-Fe(2)O(3)) constitutes one of the most promising semiconductor materials for the conversion of sunlight into chemical fuels by water splitting. Its inherent drawbacks related to the long penetration depth of light and poor charge carrier conductivity are being progressively overcome by employing nanostructuring strategies and improved catalysts. However, the physical-chemical mechan...