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...

To improve the optoelectronic properties of hematite film as a photoanode, hematite film was orientated on the (012) plane by the secondary growth of organized microcrystals. The resultant film showed promising photoelectrochemical effects compared with a randomly oriented one, with a maximum photocurrent of 0.8 mA cm(-2) at 1.23 V vs. RHE under the illumination of 1 sun.

Transient absorption spectroscopy on subpicosecond to second time scales is used to investigate photogenerated charge carrier recombination in Si-doped nanostructured hematite (α-Fe2O3) photoanodes as a function of applied bias. For unbiased hematite, this recombination exhibits a 50% decay time of ~6 ps, ~10(3) times faster than that of TiO2 under comparable conditions. Anodic bias significant...

The impact of zinc on the reductive dissolution of hematite by the dissimilatory metal-reducing bacterium Shewanella putrefaciens CN32 was studied in batch culture mode. Experiments were conducted with hematite (2.0 g L 1) in 10 mM PIPES (pH 6.8) and H2 as the electron donor under nongrowth conditions (108 cell mL 1), spiked with zinc (0 to 0.23 mM), and incubated for 5 days. Experiments were a...

As part of a study of the effect of particle size on reactivity of hematite to aqueous metal ions, the sorption of Zn(II) on hematite nanoparticles and microparticles was examined over a wide range of Zn(II) concentrations using Zn K-edge EXAFS. When reacted with nanoparticles at pH 5.5 and low Zn(II) sorption densities (0.04 < Γ < 2.76 μmol/m), Zn(II) formed five-coordinated or a mixture of fo...

Hematite is a promising catalyst for the photoelectrochemical water oxidation reaction, which however displays a low overall efficiency. To improve it, a systematic understanding of the underlying photocatalytic mechanisms is desirable but difficult to obtain by experimental techniques alone. Here, we have investigated the oxidation of water on the most stable terminations of the bare hematite,...

-Mixtures of synthetic Al-substituted goethite (a-Feo.814AloA86OOH) and hematite (a-Fel.658Alo.34203) (75, 50, 25, 3~ hematite by weight) were studied by M6ssbauer spectroscopy to evaluate the use of that technique for quantitative analysis. M6ssbauer spectra for these mixtures, obtained in the temperature range 12-130 K, were better fitted by a distribution of magnetic fields than by two magne...

In this work we present an investigation of the influence of particle surface characteristics on the electrorheological (ER) behavior of suspensions of either pure or modified hematite (α-Fe(2)O(3)) particles dispersed in silicone oil. The modification consisted of either dehydration or hydrophobization of the particles before preparing the suspensions. A comparison was performed between the el...

Hematite or α-Fe2O3 has emerged as a highly promising photoanode candidate for photoelectrochemical cells. While significant improvements in its performance have recently been achieved, it remains unclear why the maximum photocurrents still remain well below their theoretical predictions. Here, we report, for the first time, a detailed correlation between the electrical conductivity of undoped ...

Samples of Banded Iron Formation (BIF) with different quartz and hematite contents were deformed in axial compression experiments in a Griggs-type apparatus, at T = 900oC, P =1.5 GPa and strain rates of 10-5 and 10-6 s-1. The aim is to investigate the mineral phase that controls the rheology of multi-phase rocks and to determine the processes that control the observed rock strength. BIF samples...