Topic
Feroxyhyte
About: Feroxyhyte is a research topic. Over the lifetime, 97 publications have been published within this topic receiving 2536 citations. The topic is also known as: IMA1975-032.
Papers published on a yearly basis
Papers
TL;DR: In this paper, the authors report on the use of synthetic and natural Fe (hydr)oxides as catalysts in environmental remediation procedures using an advanced oxidation process, more specifically the Fentonlike system, which is highly efficient in generating reactive species such as hydroxyl radicals, even at room temperature and under atmospheric pressure.
Abstract: Iron is the fourth most common element by mass in the Earth’s crust and forms compounds in several oxidation states. Iron (hydr)oxides, some of which form inherently and exclusively in the nanometre-size range, are ubiquitous in nature and readily synthesized. These facts add up to render many Fe (hydr)oxides suitable as catalysts, and it is hardly surprising that numerous studies on the applications of Fe (hydr)oxides in catalysis have been published. Moreover, the abundant availability of a natural Fe source from rocks and soils at minimal cost makes the potential use of these as heterogeneous catalyst attractive.
Besides those Fe (hydr)oxides that are inherently nanocrystalline (ferrihydrite, Fe5HO8·4H2O, and feroxyhyte, δ′-FeOOH), magnetite (Fe3O4) is often used as a catalyst because it has a permanent magnetization and contains Fe in both the divalent and trivalent states. Hematite, goethite and lepidocrocite have also been used as catalysts in their pure forms, doped with other cations, and as composites with carbon, alumina and zeolites among others.
In this review we report on the use of synthetic and natural Fe (hydr)oxides as catalysts in environmental remediation procedures using an advanced oxidation process, more specifically the Fenton-like system, which is highly efficient in generating reactive species such as hydroxyl radicals, even at room temperature and under atmospheric pressure. The catalytic efficiency of Fe (hydr)oxides is strongly affected by factors such as the Fe oxidation state, surface area, isomorphic substitution of Fe by other cations, pH and temperature.
385 citations
TL;DR: It is demonstrated for the first time that iron cation vacancies induce superb water splitting bifunctionality in alkaline media and the atomic level insight into the new catalyst activation principle based on metal vacancies is adaptable for developing other transition metal electrocatalysts, including Fe-based ones.
Abstract: Exploring of new catalyst activation principle holds a key to unlock catalytic powers of cheap and earth-abundant materials for large-scale applications. In this regard, the vacancy defects have been proven to be effective to initiate catalytic active sites and endow high electrocatalytic activities. However, such electrocatalytically active defects reported to date have been mostly formed by anion vacancies. Herein, it is demonstrated for the first time that iron cation vacancies induce superb water splitting bifunctionality in alkaline media. A simple wet-chemistry method is developed to grow ultrathin feroxyhyte (δ-FeOOH) nanosheets with rich Fe vacancies on Ni foam substrate. The theoretical and experimental results confirm that, in contrast to anion vacancies, the formation of rich second neighboring Fe to Fe vacancies in δ-FeOOH nanosheets can create catalytic active centers for both hydrogen and oxygen evolution reactions. The atomic level insight into the new catalyst activation principle based on metal vacancies is adaptable for developing other transition metal electrocatalysts, including Fe-based ones.
283 citations
TL;DR: A multisite surface complexation (MUSIC) model for ferrihydrite (Fh) has been developed in this article, where the surface structure and composition of Fh nanoparticles are described in relation to ion binding and surface charge development.
275 citations
TL;DR: A large vibrational spectroscopic database is provided for comparison of As(III) and As(V) speciation in aqueous solutions and at the iron oxide - solution interface to contribute to a better understanding of arsenic complexation by iron oxides.
175 citations
TL;DR: In this article, a tuneable dye laser was used to enhance the Raman spectra for the detection of iron oxide and iron oxyhydroxide compounds using an excitation wavelength of 636.4 nm.
Abstract: Raman spectroscopy, in principle, is an excellent technique for the study of molecular species developed on metal surfaces during electrochemical investigations. However, the use of the more common laser wavelengths such as the 514.5-nm line results in spectra of less than optimal intensity, particularly for iron oxide compounds. In the present work, near-resonance enhancement of the Raman spectra was investigated for the iron oxide and iron oxyhydroxide compounds previously reported to be present in the passive film on iron, using a tuneable dye laser producing excitation wavelengths between 560 and 637 nm. These compounds were hematite (α-Fe2O3), maghemite (γ-Fe2O3), magnetite (Fe3O4), goethite (α-FeOOH), akaganeite (β-FeOOH), lepidocrocite (γ-FeOOH) and feroxyhyte (δ-FeOOH). Optimum enhancement, when compared to that with the 514.5-nm line, was obtained for all the iron oxide and oxyhydroxide standard samples in the low wavenumber region (<1000 cm−1) using an excitation wavelength of 636.4 nm. Particularly significant enhancement was obtained for lepidocrocite, hematite and goethite. Copyright © 2010 John Wiley & Sons, Ltd.
158 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 9 |
| 2020 | 5 |
| 2019 | 6 |
| 2018 | 7 |
| 2017 | 7 |
| 2016 | 7 |