Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics, and drug delivery. The surface or material interface can be performance-limiting in these applications, so it is vital to determine accurate atomic-scale structures for iron oxides and understand why they form. Using a combination of quantitative low-energy electron diffraction, scannin...

[1] Sediment cores from the intertidal zone of Waquoit Bay (Cape Cod, Massachusetts) yielded iron oxide-coated sands in the subterranean estuary, which underlies the head of the bay. The oxides were dark red, yellow and orange colors and are formed by the oxidation of ferrous iron-rich groundwater near the groundwaterseawater interface. Within these iron oxide-rich sediments, the concentration ...

Selenate (SeO4(2-)) is an oxyanion of environmental importance because of its toxicity to animals and its mobility in the soil environment. It is known that iron(III) oxides and hydroxides are important sorbents for SeO4(2-) in soils and sediments, but the mechanism of selenate adsorption on iron oxides has been the subject of intense debate. Our research employed Extended X-ray absorption fine...

Iron oxides catalyze the conversion of hydrogen peroxide (H(2)O(2)) into oxidants capable of transforming recalcitrant contaminants. Unfortunately, the process is relatively inefficient at circumneutral pH values because of competing reactions that decompose H(2)O(2) without producing oxidants. Silica- and alumina-containing iron oxides prepared by sol-gel processing of aqueous solutions contai...

Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing micro...

3. Soluble Metal Oxides 2459 3.1. Polyoxometalates 2459 3.2. Peroxotungstates 2459 3.3. Peroxomolybdates 2460 3.4. Methyltrioxorhenium 2461 3.5. Other Metal Oxides 2461 4. Metal Oxides Generated in Situ 2461 4.1. Selenium and Arsenic Compounds 2461 4.2. Simple Metal Salts 2462 5. Coordination Complexes 2463 5.1. Manganese Porphyrins 2463 5.2. Iron Porphyrins 2464 5.3. Manganese Salen Complexes ...

Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully rec...

Some bacteria utilize (semi)conductive iron-oxide minerals as conduits for extracellular electron transfer (EET) to distant, insoluble electron acceptors. A previous study demonstrated that microbe/mineral conductive networks are constructed in soil ecosystems, in which Geobacter spp. share dominant populations. In order to examine how (semi)conductive iron-oxide minerals affect EET paths of Ge...

We have hypothesized (Negro et al. 1999) that bearded vultures, Gypaetus barbatus, deliberately stain their plumage with iron oxides to signal dominance status. The conceptual frame to which we ascribe our hypothesis is the handicap principle (Zahavi & Zahavi 1997). For a signal to convey reliable information, and thus to evolve, it has to be costly (Zahavi 1975), and we proposed that the assoc...

Neutrophilic, bacterial iron-oxidation remains one of the least understood energy-generating biological reactions to date. One of the reasons it remains under-studied is because there are inherent problems with working with iron-oxidizing bacteria (FeOB), including low biomass yields and interference from the iron oxides in the samples. In an effort to circumvent the problem of low biomass, a n...