Showing papers on "Iron oxide published in 2015"
TL;DR: In this article, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to bio-field treatment.
Abstract: Transition metal oxides (TMOs) have been known for their extraordinary electrical and magnetic properties. In the present study, some transition metal oxides (Zinc oxide, iron oxide and copper oxide) which are widely used in the fabrication of electronic devices were selected and subjected to biofield treatment. The atomic and crystal structures of TMOs were carefully studied by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) studies. XRD analysis reveals that biofield treatment significantly changed the lattice strain in unit cells, crystallite sizes and densities in ceramics oxide powders. The computed molecular weight of the treated samples exhibited significant variation. FT-IR spectra indicated that biofield treatment has altered the metal-oxygen bond strength. Since biofield treatment significantly altered the crystallite size, lattice strain and bond strength, we postulate that electrical and magnetic properties in TMOs (transition metal oxides) can be modulated by biofield treatment.
303 citations
TL;DR: In this paper, the performance of single basin single slope solar still with and without water nanofluid was compared and two experimental stills of the same basin area have been fabricated and tested with water and different nanophluids simultaneously.
265 citations
TL;DR: A porous Ni–Fe oxide with improved crystallinity has been prepared as a highly efficient electrocatalytic water oxidation catalyst that has a small overpotential, a low Tafel slope, and an outstanding stability.
Abstract: A porous Ni-Fe oxide with improved crystallinity has been prepared as a highly efficient electrocatalytic water oxidation catalyst. It has a small overpotential, a low Tafel slope, and an outstanding stability. The remarkably improved electrocatalytic performance is due to the porous structure, high extent homogeneous iron incorporation, ameliorative crystallinity, and the low mass transfer resistance.
238 citations
TL;DR: This work presents a comprehensive template for the design and synthesis of iron oxide nanoparticles with control over size, size distribution, phase, and resulting magnetic properties, and describes how phase purity can be controlled.
Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are used for a wide range of biomedical applications requiring precise control over their physical and magnetic properties, which are dependent on their size and crystallographic phase. Here we present a comprehensive template for the design and synthesis of iron oxide nanoparticles with control over size, size distribution, phase, and resulting magnetic properties. We investigate critical parameters for synthesis of monodisperse SPIONs by organic thermal decomposition. Three different, commonly used, iron containing precursors (iron oleate, iron pentacarbonyl, and iron oxyhydroxide) are evaluated under a variety of synthetic conditions. We compare the suitability of these three kinetically controlled synthesis protocols, which have in common the use of iron oleate as a starting precursor or reaction intermediate, for producing nanoparticles with specific size and magnetic properties. Monodisperse particles were produced over a tunable range of sizes from approximately 2–30 nm. Reaction parameters such as precursor concentration, addition of surfactant, temperature, ramp rate, and time were adjusted to kinetically control size and size-distribution, phase, and magnetic properties. In particular, large quantities of excess surfactant (up to 25 : 1 molar ratio) alter reaction kinetics and result in larger particles with uniform size; however, there is often a trade-off between large particles and a narrow size distribution. Iron oxide phase, in addition to nanoparticle size and shape, is critical for establishing magnetic properties such as differential susceptibility (dm/dH) and anisotropy. As an example, we show the importance of obtaining the required size and iron oxide phase for application to Magnetic Particle Imaging (MPI), and describe how phase purity can be controlled. These results provide much of the information necessary to determine which iron oxide synthesis protocol is best suited to a particular application.
237 citations
TL;DR: It is shown that methane produced in Bothnian Sea sediments is oxidized in distinct zones of iron- and sulfate-dependent AOM, the first field evidence for iron- dependent AOM in brackish coastal surface sediments and Laboratory incubation studies of these sediments suggest that the in situ microbial community is capable of linking methane oxidation to iron oxide reduction.
Abstract: Methane is a powerful greenhouse gas and its biological conversion in marine sediments, largely controlled by anaerobic oxidation of methane (AOM), is a crucial part of the global carbon cycle. However, little is known about the role of iron oxides as an oxidant for AOM. Here we provide the first field evidence for iron-dependent AOM in brackish coastal surface sediments and show that methane produced in Bothnian Sea sediments is oxidized in distinct zones of iron- and sulfate-dependent AOM. At our study site, anthropogenic eutrophication over recent decades has led to an upward migration of the sulfate/methane transition zone in the sediment. Abundant iron oxides and high dissolved ferrous iron indicate iron reduction in the methanogenic sediments below the newly established sulfate/methane transition. Laboratory incubation studies of these sediments strongly suggest that the in situ microbial community is capable of linking methane oxidation to iron oxide reduction. Eutrophication of coastal environments may therefore create geochemical conditions favorable for iron-mediated AOM and thus increase the relevance of iron-dependent methane oxidation in the future. Besides its role in mitigating methane emissions, iron-dependent AOM strongly impacts sedimentary iron cycling and related biogeochemical processes through the reduction of large quantities of iron oxides.
234 citations
TL;DR: A flexible electrode, based on carbon cloth substrate and iron phosphide nanotubes coated with an iron oxide/phosphate layer, is shown to catalyze overall water splitting and demonstrates remarkable electrocatalytic activity for both the hydrogen evolution reaction (HER) and the oxygen evolution Reaction (OER) at modest overpotentials.
Abstract: The design of cheap and efficient water splitting systems for sustainable hydrogen production has attracted increasing attention. A flexible electrode, based on carbon cloth substrate and iron phosphide nanotubes coated with an iron oxide/phosphate layer, is shown to catalyze overall water splitting. The as-prepared flexible electrode demonstrates remarkable electrocatalytic activity for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) at modest overpotentials. The surface iron oxide/phosphate, which is formed in situ, is proposed to improve the HER activity by facilitating the water-dissociation step and serves directly as the catalytically-active component for the OER process.
224 citations
TL;DR: In this article, a 25-wt% Mn 0.75 Fe 0.25 Ti-DP catalyst, prepared by deposition precipitation with ammonium carbamate (AC) as a precipitating agent, showed superior low-temperature SCR (selective catalytic reduction) of NO with NH 3.
Abstract: Mn/TiO 2 and Mn–Fe/TiO 2 catalysts have been prepared by impregnation (IMP) and deposition-precipitation (DP) techniques and characterized by N 2 physisorption, XRPD, NH 3 -TPD, H 2 -TPR, XPS and TGA. 25 wt% Mn 0.75 Fe 0.25 Ti-DP catalyst, prepared by deposition precipitation with ammonium carbamate (AC) as a precipitating agent, showed superior low-temperature SCR (selective catalytic reduction) of NO with NH 3 . The superior catalytic activity of the 25 wt% Mn 0.75 Fe 0.25 Ti-DP catalyst is probably due to the presence of amorphous phases of manganese oxide, iron oxide, high surface area, high total acidity, acid strength and ease of reduction of manganese oxide and iron oxide on TiO 2 in addition to formation of an SCR active MnO x phase with high content of chemisorbed oxygen (O α ). The optimum catalyst might be used as tail-end SCR catalysts in, e.g., biomass-fired power plants and waste incineration plants.
217 citations
TL;DR: A reproducible and potentially scalable microwave-based method to make stable citric acid coated multi-core iron oxide nanoparticles, with exceptional magnetic heating parameters, viz. intrinsic loss parameters (ILPs) of up to 4.1 nH m(2) kg(-1), 35% better than the best commercial equivalents.
Abstract: The adoption of magnetic hyperthermia as either a stand-alone or adjunct therapy for cancer is still far from being optimised due to the variable performance found in many iron oxide nanoparticle systems, including commercially available formulations. Herein, we present a reproducible and potentially scalable microwave-based method to make stable citric acid coated multi-core iron oxide nanoparticles, with exceptional magnetic heating parameters, viz. intrinsic loss parameters (ILPs) of up to 4.1 nH m2 kg−1, 35% better than the best commercial equivalents. We also probe the core-to-core magnetic interactions in the particles via remanence-derived Henkel and ΔM plots. These reveal a monotonic dependence of the ILP on the magnetic interaction field Hint, and show that the interactions are demagnetising in nature, and act to hinder the magnetic heating mechanism.
214 citations
TL;DR: In this paper, the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit in Chile has been studied using laser ablation-inductively coupled plasma mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping.
183 citations
TL;DR: The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles and the results showed a noteworthy inhibition on both bacterial strains.
177 citations
TL;DR: Sulfidization was a dominant pathway in iron reduction despite low sulfate concentrations and regardless of iron oxide substrate, indicating that sulfur (re)cycling is a dominant force in iron cycling even in low-sulfate systems and in a manner difficult to predict using the classical thermodynamic ladder.
Abstract: A central tenant in microbial biogeochemistry is that microbial metabolisms follow a predictable sequence of terminal electron acceptors based on the energetic yield for the reaction. It is thereby oftentimes assumed that microbial respiration of ferric iron outcompetes sulfate in all but high-sulfate systems, and thus sulfide has little influence on freshwater or terrestrial iron cycling. Observations of sulfate reduction in low-sulfate environments have been attributed to the presumed presence of highly crystalline iron oxides allowing sulfate reduction to be more energetically favored. Here we identified the iron-reducing processes under low-sulfate conditions within columns containing freshwater sediments amended with structurally diverse iron oxides and fermentation products that fuel anaerobic respiration. We show that despite low sulfate concentrations and regardless of iron oxide substrate (ferrihydrite, Al-ferrihydrite, goethite, hematite), sulfidization was a dominant pathway in iron reduction. This process was mediated by (re)cycling of sulfur upon reaction of sulfide and iron oxides to support continued sulfur-based respiration—a cryptic sulfur cycle involving generation and consumption of sulfur intermediates. Although canonical iron respiration was not observed in the sediments amended with the more crystalline iron oxides, iron respiration did become dominant in the presence of ferrihydrite once sulfate was consumed. Thus, despite more favorable energetics, ferrihydrite reduction did not precede sulfate reduction and instead an inverse redox zonation was observed. These findings indicate that sulfur (re)cycling is a dominant force in iron cycling even in low-sulfate systems and in a manner difficult to predict using the classical thermodynamic ladder.
TL;DR: Modulation of nanoparticles reactivity to the biological environment by the choice of materials and surface functionalization may provide new directions in the design of multifunctional nanomedicines with predictable fate.
Abstract: Safe implementation of nanotechnology and nanomedicine requires an in-depth understanding of the life cycle of nanoparticles in the body. Here, we investigate the long-term fate of gold/iron oxide heterostructures after intravenous injection in mice. We show these heterostructures degrade in vivo and that the magnetic and optical properties change during the degradation process. These particles eventually eliminate from the body. The comparison of two different coating shells for heterostructures, amphiphilic polymer or polyethylene glycol, reveals the long lasting impact of initial surface properties on the nanocrystal degradability and on the kinetics of elimination of magnetic iron and gold from liver and spleen. Modulation of nanoparticles reactivity to the biological environment by the choice of materials and surface functionalization may provide new directions in the design of multifunctional nanomedicines with predictable fate.
TL;DR: This review article reports on some of the most recent experimental and theoretical studies on magnetic heating mechanisms under an alternating (AC) magnetic field and reports on the recently discovered photoluminescence of Fe3O4 and explains the emission mechanisms in terms of the electronic band structures.
Abstract: Iron oxide exhibits fascinating physical properties especially in the nanometer range, not only from the standpoint of basic science, but also for a variety of engineering, particularly biomedical applications. For instance, Fe3O4 behaves as superparamagnetic as the particle size is reduced to a few nanometers in the single-domain region depending on the type of the material. The superparamagnetism is an important property for biomedical applications such as magnetic hyperthermia therapy of cancer. In this review article, we report on some of the most recent experimental and theoretical studies on magnetic heating mechanisms under an alternating (AC) magnetic field. The heating mechanisms are interpreted based on Neel and Brownian relaxations, and hysteresis loss. We also report on the recently discovered photoluminescence of Fe3O4 and explain the emission mechanisms in terms of the electronic band structures. Both optical and magnetic properties are correlated to the materials parameters of particle size, distribution, and physical confinement. By adjusting these parameters, both optical and magnetic properties are optimized. An important motivation to study iron oxide is due to its high potential in biomedical applications. Iron oxide nanoparticles can be used for MRI/optical multimodal imaging as well as the therapeutic mediator in cancer treatment. Both magnetic hyperthermia and photothermal effect has been utilized to kill cancer cells and inhibit tumor growth. Once the iron oxide nanoparticles are up taken by the tumor with sufficient concentration, greater localization provides enhanced effects over disseminated delivery while simultaneously requiring less therapeutic mass to elicit an equal response. Multi-modality provides highly beneficial co-localization. For magnetite (Fe3O4) nanoparticles the co-localization of diagnostics and therapeutics is achieved through magnetic based imaging and local hyperthermia generation through magnetic field or photon application. Here, Fe3O4 nanoparticles are shown to provide excellent conjugation bases for entrapment of therapeutic molecules, fluorescent agents, and targeting ligands; enhancement of solid tumor treatment is achieved through co-application of local hyperthermia with chemotherapeutic agents.
TL;DR: The aging effects of nZVI, prepared using a borohydride reduction method in static water over a period of 90 days (d), are investigated and the patterns of occurrence of specific iron oxides in different natural conditions are explained.
TL;DR: A short review of methods for obtaining nanoparticulate iron oxides and characteristics of the different characterization techniques and decomposition of these nanomaterials can be found in this article.
Abstract: Iron oxide is a polymorphous crystalline mineral, including hematite, a-Fe 2 O 3 , magnetite, Fe 3 O 4 and maghemite, g-Fe 2 O 3 . In the area of solid propulsion, nanoparticulate materials such, hematite and maghemite, exhibit high performance on thermal decomposition of ammonium perchlorate (AP).The best catalytic effect of metallic iron oxide nanoparticles was attributed to its small particle size, more active sites and high surface area, which prove most gas adsorption of released products during the thermal reactions of oxidizer. Nowadays, metallic iron nanoparticles can be synthesized via many methods, by co-precipitation, sol-gel, microemulsion, or thermal decomposition. Although there are data on these synthetic methods in the literature, there is a lack of details in nanoparticulate oxides and on the characterization techniques used. In this context, this short review presents methods for obtaining nanoparticulate iron oxides and characteristics of the different characterization techniques and decomposition of these nanomaterials. The morphologies and structures can be characterized by transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, and FT- IR spectroscopy and the textural properties by physical adsorption.
TL;DR: In this article, the effect of support pore sizes on the structure and performance of iron catalysts supported by mesoporous silicas in high-temperature Fischer-Tropsch synthesis was addressed.
TL;DR: Iron oxide impregnation enabled the BPA uptake to be maintained in the presence of NOM, indicating that the hybrid adsorbent provided synergistic adsorption characteristics for BPA and NOM.
TL;DR: In this paper, the synthesis of metallic and bimetallic nanoparticles such as spherical iron oxide nanoparticles, rod iron oxide and iron@gold nanoparticles (Fe3O4@AuNPs) for methanol electro-oxidation was reported.
Abstract: Fuel cells have been attracting more and more attention in recent decades due to high-energy demands, fossil fuel depletions and environmental pollution throughout world In this study, we report the synthesis of metallic and bimetallic nanoparticles such as spherical iron oxide nanoparticles [(sp)Fe3O4], rod iron oxide nanoparticles [(rd)Fe3O4] and iron@gold nanoparticles (Fe3O4@AuNPs) involving L-cysteine functionalized reduced graphene oxide nanohybrids [(sp)Fe3O4/cys/rGO, (rd)Fe3O4/cys/rGO and Fe3O4@AuNPs/cys/rGO] and their application as an electrocatalyst for methanol electro-oxidation The nanohybrids have been characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) The experimental results have demonstrated that reduced graphene oxide-supported bimetallic nanoparticles enhanced the electrochemical efficiency for methanol electro-oxidation with regard to diffusion efficiency, oxidation potential and forward oxidation peak current Fe3O4@AuNPs/cys/rGO, in comparison to (sp)Fe3O4/cys/rGO and (rd)Fe3O4/cys/rGO, showed the most efficiency for methanol electro-oxidation
TL;DR: In this paper, a variety of functionalized and structurally diverse anilines, which serve as key building blocks and central intermediates for fine and bulk chemicals, were synthesized in good to excellent yields.
Abstract: Nanoscaled iron oxides on carbon were modified with nitrogen-doped graphene (NGr) and found to be excellent catalysts for the chemoselective transfer hydrogenation of nitroarenes to anilines. Under standard reaction conditions, a variety of functionalized and structurally diverse anilines, which serve as key building blocks and central intermediates for fine and bulk chemicals, were synthesized in good to excellent yields.
TL;DR: An increase in solution viscosity led to lower heating rates in nanoparticle solutions, which can have significant implications for the application of magnetic fluid hyperthermia in vivo.
TL;DR: In this article, a thermal decomposition of iron oxide (FeOL) in the presence of sodium oleate (NaOL) was used to obtain monodisperse iron oxide nanostructures with diverse morphology.
Abstract: Controlled synthesis of monodisperse iron oxide (IO) nanostructures with diverse morphology remains a major challenge. In this work, IO nanostructures with various shapes and surface structures were synthesized by thermal decomposition of iron oleate (FeOL) in the presence of sodium oleate (NaOL). In a mild condition using 1-octadecene (ODE) as solvent, NaOL may preferentially bind to Fe3O4{111} facets and lead to the formation of Fe3O4{111} facet exposed IO plates, truncated octahedrons, and tetrahedrons. While in a high-boiling temperature tri-n-octylamine (TOA) solvent, we obtained Fe3O4{100} facet exposed IO cubes, concaves, multibranches, and assembled structures by varying the molar ratios of NaOL/FeOL. Moreover, we demonstrated that IO nanoparticles (NPs) with metal-exposed surface structures have enhanced T1 relaxation time shortening effects to protons, and IO NPs with anisotropic shapes are superior in protons T2 relaxation shortening due to the larger effective radii compared to that of spheric...
TL;DR: The findings of this study will increase the current understanding of the natural biological attenuation of aromatic hydrocarbons in anaerobic environments by evaluating the possibility that conductive iron oxides (hematite and magnetite) can stimulate the methanogenic degradation of benzoate.
TL;DR: In this paper, a comparative study of isolated FeII, iron oxide particles, and metallic nanoparticles on silica for non-oxidative propane dehydrogenation was performed.
Abstract: We report a comparative study of isolated FeII, iron oxide particles, and metallic nanoparticles on silica for non-oxidative propane dehydrogenation. It was found that the most selective catalyst was an isolated FeII species on silica prepared by grafting the open cyclopentadienide iron complex, bis(2,4-dimethyl-1,3-pentadienide) iron(II) or Fe(oCp)2. The grafting and evolution of the surface species was elucidated by 1H NMR, diffuse reflectance infrared Fourier transform spectroscopy and X-ray absorption spectroscopies. The oxidation state and local structure of surface Fe were characterized by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure. The initial grafting of iron proceeds by one surface hydroxyl Si–OH reacting with Fe(oCp)2 to release one diene ligand (oCpH), generating a SiO2-bound FeII(oCp) species, 1-FeoCp. Subsequent treatment with H2 at 400 °C leads to loss of the remaining diene ligand and formation of nanosized iron oxide clusters, 1-C. Dispersion ...
TL;DR: In this article, a review summarizes the research progress in the preparation of graphene based iron oxide composites for electrochemical energy storage and conversion devices like lithium ion batteries, supercapacitors and fuel cells.
TL;DR: In this paper, the effect of support on the cyclic redox performance of iron oxides as well as the underlying mechanisms were investigated. But, the results indicated that the redox properties of the oxygen carrier, e.g. activity and long-term stability, are significantly affected by support and iron oxide interactions.
Abstract: The chemical looping processes utilize lattice oxygen in oxygen carriers to convert carbonaceous fuels in a cyclic redox mode while capturing CO2. Typical oxygen carriers are composed of a primary oxide for active lattice oxygen storage and a ceramic support for enhanced redox stability and activity. Among the various primary oxides reported to date, iron oxide represents a promising option due to its low cost and natural abundance. The current work investigates the effect of support on the cyclic redox performance of iron oxides as well as the underlying mechanisms. Three ceramic supports with varying physical and chemical properties, i.e. perovskite-structured Ca0.8Sr0.2Ti0.8Ni0.2O3, fluorite-structured CeO2, and spinel-structured MgAl2O4, are investigated. The results indicate that the redox properties of the oxygen carrier, e.g. activity and long-term stability, are significantly affected by support and iron oxide interactions. The perovskite supported oxygen carrier exhibits high activity and stability compared to oxygen carriers with ceria support, which deactivate by as much as 75% within 10 redox cycles. The high stability of perovskite supported oxygen carrier is attributable to its high mixed ionic–electronic conductivity. Deactivation of ceria supported samples results from solid-state migration of iron cations and subsequent enrichment on the oxygen carrier surface. This leads to agglomeration and lowered lattice oxygen accessibility. Activity of MgAl2O4 supported oxygen carrier is found to increase during redox cycles in methane. The activity increase is a consequence of surface area increase caused by filamentous carbon formation and oxygen carrier fragmentation. While higher redox activity is desired for chemical looping processes, physical degradation of oxygen carriers can be detrimental.
TL;DR: The synthesis of more than 40 amines, which are important feedstocks and key intermediates for pharmaceuticals, agrochemicals and polymers, are reported herein.
Abstract: Hydrogenation of functionalized substrates often relies on expensive noble metal—based catalysts. Jagadeesh et al. detail the hydrogenation of nitroarenes and the reductive amination of aldehydes with nitroarenes performed with an iron-based catalyst.
TL;DR: In this paper, the effect of microwave radiation on Egyptian high phosphorus iron ore was investigated, and the results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases.
TL;DR: It was found the surface area normalized Cr(VI) removal rate constants of Fe@Fe2O3 nanowires first increased with increasing the iron oxide shell thickness and then decreased, suggesting that Fe@ Fe 2O3 Nanowires possessed an interesting core-shell structure dependent Cr( VI) removal property.
Abstract: In this study, we investigated the anoxic Cr(VI) removal with core–shell Fe@Fe2O3 nanowires. It was found the surface area normalized Cr(VI) removal rate constants of Fe@Fe2O3 nanowires first increased with increasing the iron oxide shell thickness and then decreased, suggesting that Fe@Fe2O3 nanowires possessed an interesting core–shell structure dependent Cr(VI) removal property. Meanwhile, the Cr(VI) removal efficiency was positively correlated to the amount of surface bound Fe(II). This result revealed that the core–shell structure dependent Cr(VI) removal property of Fe@Fe2O3 nanowires was mainly attributed to the reduction of Cr(VI) by the surface bound Fe(II) besides the reduction of Cr(VI) adsorbed on the iron oxide shell via the electrons transferred from the iron core. The indispensable role of surface bound Fe(II) was confirmed by Tafel polarization and high-resolution X-ray photoelectron spectroscopic depth profiles analyses. X-ray diffraction patterns and scanning electron microscope images o...
TL;DR: It is proposed that the chemodenitrification rate is insensitive to the type of Fe(III) (hydr)oxide, and stable isotope measurements reveal a narrow range of isotopic fractionation during NO2- reduction to N2O.
Abstract: When oxygen is limiting in soils and sediments, microorganisms utilize nitrate (NO3-) in respiration--through the process of denitrification--leading to the production of dinitrogen (N2) gas and trace amounts of nitrous (N2O) and nitric (NO) oxides. A chemical pathway involving reaction of ferrous iron (Fe2+) with nitrite (NO2-), an intermediate in the denitrification pathway, can also result in production of N2O. We examine the chemical reduction of NO2- by Fe(II)--chemodenitrification--in anoxic batch incubations at neutral pH. Aqueous Fe2+ and NO2- reacted rapidly, producing N2O and generating Fe(III) (hydr)oxide mineral products. Lepidocrotite and goethite, identified by synchrotron X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy, were produced from initially aqueous reactants, with two-line ferrihydrite increasing in abundance later in the reaction sequence. Based on the similarity of apparent rate constants with different mineral catalysts, we propose that the chemodenitrification rate is insensitive to the type of Fe(III) (hydr)oxide. With stable isotope measurements, we reveal a narrow range of isotopic fractionation during NO2- reduction to N2O. The location of N isotopes in the linear N2O molecule, known as site preference, was also constrained to a signature range. The coexistence of Fe(III) (hydr)oxide, characteristic 15N and 18O fractionation, and N2O site preference may be used in combination to qualitatively distinguish between abiotic and biogenically emitted N2O--a finding important for determining N2O sources in natural systems.
TL;DR: In this paper, an iron based metal organic framework loaded on iron oxide nanoparticles (Fe3O4@MIL-100(Fe)) and its capability for the removal of methyl red was investigated.