Iron Nitrate Solution Research Articles

Behavior of fission products in the course of dissolution of simulated spent nuclear fuel in iron nitrate solutions and of recovery of uranium and plutonium from the resulting solutions

Experiments aimed to examine the spent nuclear fuel dissolution in iron(III) nitrate solutions and to elucidate the behavior of fission products in the process were performed with simulated fuel corresponding to spent nuclear fuel of a WWER-1000 reactor. In Fe(III) nitrate solutions, U is quantitatively transferred from the fuel together with Cs, Sr, Ba, Y, La, and Ce, whereas Mo, Tc, and Ru remain in the insoluble precipitate and do not pass into the solution, and Nd, Zr, and Pd pass into the solution to approximately 50%. The recovery of U or jointly U + Pu from the solution after the dissolution of oxide nuclear fuel is performed by precipitation of their peroxides, which allows efficient separation of actinides from residues of fission products and iron.

Soft Chemistry Preparation of lead Iron Vanadate

In order to prepare the new monoclinic Pb2FeV3O11 at low temperature; an acidic solution of vanadium oxide, pH 2, was mixed with a corresponding amount of both lead and iron nitrate at boiling temperature. The yellow precipitate obtained is a mixture of lead pyrovanadate Pb2V2O7 and an amorphous phase. At 500°C, the new monoclinic Pb2FeV3O11 phase appears but mixed with Pb2V2O7. At higher temperature, 570°C, the monoclinic phase disappears and a new phase appears. This phase is similar to triclinic Pb2Fe2V4O15, recently reported, although the EDAX analysis shows the as-prepared sample with higher amount of vanadium and iron. To understand the mechanism involved, lead and iron nitrate solution were reacted separately with vanadium oxide solution. The phases formed were found to be sensitive to initial concentration and to stirring time

Catalytic Oxidation of Toluene over Fe<sub>2</sub>O<sub>3</sub>/Al<sub>2</sub>O<sub>3</sub> Catalyst

Fe2O3/Al2O3 catalyst was prepared and the catalytic oxidation of toluene over the catalyst was investigated. The catalyst was prepared by wet impregnation of commercial alumina support. The support was impregnated with an aqueous solution of iron nitrate. The wet support was dried and calcined at 600-800 °C. The catalytic property of the catalyst was measured by the light-off curve of CO2 yield. All these catalysts were active for total oxidation of toluene above 250 °C. The catalytic activity of catalyst calcined at 600 °C was better than those of catalysts calcined at 700 and 800 °C.

Preparation of hierarchically meso-macroporous hematite Fe2O3 using PMMA as imprint template and its reaction performance for Fischer–Tropsch synthesis

The paper described a facile approach to prepare hierarchically meso-macroporous hematite Fe2O3 using PMMA as imprint template and its catalytic reaction in Fischer–Tropsch synthesis (FTS). The mixed solution of iron nitrate with ethylene glycol (EG) and methanol was infiltrated into the void of the colloidal crystal of a poly(methyl methacrylate) (PMMA) sphere with size in several microns. Heating initiated nitrate oxidation of the EG to produce metal glyoxylate salt. Further heating converted the glyoxylate salt to metal oxide and the skeleton of PMMA was reserved, which produced the hierarchically mesoporous and macroporous hematite Fe2O3. The fabricated iron oxide was applied to catalyze the FTS, showing high reaction activity and stability in comparison with the conventional Fe FTS catalyst.

Bottom-up in situ formation of Fe3O4 nanocrystals in a porous carbon foam for lithium-ion battery anodes

A facile and scalable process for the in situ formation of Fe3O4 nanocrystals in a pre-formed carbon foam (CF) (Fe3O4/CF) was developed, which involved impregnation of an aqueous iron nitrate solution onto CF followed by controlled thermal treatment in an inert atmosphere. N2adsorption/desorption and BET measurements showed that the CF was a mesoporous carbon with a high pore volume and specific surface area. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction measurement, thermogravimetric analysis, and X-ray photoelectron spectroscopy (XPS) revealed that 5–50 nm Fe3O4 nanocrystals at a high loading of 78.7 wt% were formed preferentially in the confined pores of CF. When tested for anode material in a Li ion half-cell, the Fe3O4/CF composite was far superior to unsupported Fe3O4 nanocrystals, exhibiting significantly improved Coulombic efficiencies and cycling stability and achieving >780 mA h g−1 after 50 deep charge–discharge cycles with >95% cycling efficiency.

ChemInform Abstract: Preparation, Characterization, and Unusual Reactivity of Fe-MCM-41.

A new preparation method for highly dispersed iron in mesoporous MCM-41 materials has been developed, employing a methanolic solution of iron(III) nitrate. In situ EXAFS and NO adsorption followed by IR spectroscopy suggest that the resulting iron is present mainly in the form of isolated cations bound to the internal surface of the purely siliceous host material. Interchange between the Fe(II)/Fe(III) redox pair is facile, depending on the way in which the material is treated. The preparation procedure not only generates these highly dispersed iron species but also results in the formation of methoxy groups strongly bound to the MCM-41. It is suggested that the iron cations are chemically bound through siloxane bridges at silanol nests within the porous framework of the MCM-41 material.

Synthesis of SiFeC Magnetoceramics from Reverse Polycarbosilane‐Based Microemulsions

In this paper, we report the synthesis of iron‐containing SiC(O) magnetoceramics using a reverse microemulsion technique. First, an aqueous iron nitrate solution as the internal phase and a polycarbosilane (PCS)–heptane solution as the continuous phase were emulsified in the presence of a surfactant to synthesize iron‐containing PCS (Fe‐PCS) reverse microemulsion systems. After the removal of water and heptanes, the Fe‐PCS precursors were pyrolyzed at 600°–1200°C to produce magnetoceramics. The structures and magnetic properties of the ceramics obtained were characterized by using X‐ray diffraction, transmission electron microscopy, electron probe microanalysis, and superconducting quantum interference device. The results showed that the ceramics contained Fe3Si nanoparticles, which dispersed in SiCO amorphous matrix. This unique structure makes the ceramics excellent soft ferromagnetic materials with a high magnetizability and negligibe hysteresis loops.

Specific features of the mesostructure of amorphous iron(III) hydroxide xerogels synthesized in an ultrasonic field

The influence of high-power ultrasonic treatment on the structure of amorphous iron(III) hydroxide xerogels prepared by precipitation from iron(III) nitrate solutions of different concentrations has been investigated. An analysis of the small-angle neutron scattering data allowed us to reveal for the first time that ultrasound substantially affects the mesostructure of amorphous xerogels, including the homogeneity, the fractal dimension, and the size of constituting monomer particles.

A Vacuum Nano-casting Route to Magnetite Cores/Mesoporous Silica Shell Composites

Hollow mesoporous silica spheres with magnetite cores (HMSMC) have been fabricated by Vacuum Nano-casting Route. The amount of magnetite cores and saturation magnetization value can be easily adjusted by changing the concentration of iron nitrate solution used in the synthesis procedure. Furthermore, the as-prepared HMSMCs still maintain narrow mesopore distribution, high surface area and large pore volume after the hollow cores of hollow mesoporous silica spheres were filled with magnetite particles. Specially, when the saturation magnetization value of as-prepared HMSMCs reaches 22.0 emu/g, the surface area and pore volume of corresponding HMSMCs are 149 m2/g and 0.19 cm3/g, respectively, and the pore size is 2.30 nm. The corresponding samples are characterized by X-ray diffraction, N2 sorption isotherms, transmission electron microscopy and vibrating-sample magnetometer.

Synthesis and crystal structure of [Fe4O2(H2O)10(C5H5NCOO)4](NO3)8 · 2H2O

Crystals of the tetranuclear complex [Fe4O2(H2O)10(C5H5NCOO)4](NO3)8 · 2H2O are obtained by the slow evaporation of an aqueous solution of iron(III) nitrate and isonicotinic acid. According to the X-ray diffraction data, four metal atoms lie in the same plane and together with two μ3-O oxygen atoms form the fragment [Fe4(μ3-O)2]10+. The [Fe4O2(H2O)10(C5H5NCOO)4]8+ cation has been obtained and structurally characterized for the first time.

Porous Ba Ferrite Prepared from Wood Template

Ba ferrite materials with porous microstructures were prepared from a natural cedar wood template in order to investigate new electromagnetic shielding materials. The wood templates were infiltrated with barium nitrate and iron nitrate solutions (molar ratio = 1:12) and dried to form ferrite gel, then, they were sintered in air at a temperature between 800 °C and 1400 °C. The 1-dimensional porous structures were retained after sintering and the pore size was approximately 10–20 μm. These ferrites show large coercive force and anisotropy field. The largest coercive force was obtained for the specimen sintered at 800 °C.

A vacuum nano-casting route to magnetite cores/mesoporous silica shell composites

Abstract Hollow mesoporous silica spheres with magnetite cores (HMSMC) have been fabricated by Vacuum Nano-casting Route. The amount of magnetite cores and saturation magnetization value can be easily adjusted by changing the concentration of iron nitrate solution used in the synthesis procedure. Furthermore, the as-prepared HMSMCs still maintain narrow mesopore distribution, high surface area and large pore volume after the hollow cores of hollow mesoporous silica spheres were filled with magnetite particles. Specially, when the saturation magnetization value of as-prepared HMSMCs reaches 22.0 emu/g, the surface area and pore volume of corresponding HMSMCs are 149 m2/g and 0.19 cm3/g, respectively, and the pore size is 2.30 nm. The corresponding samples are characterized by X-ray diffraction, N2 sorption isotherms, transmission electron microscopy and vibrating-sample magnetometer.

Hollow Mesoporous Carbon Spheres with Magnetic Cores and Their Performance as Separable Bilirubin Adsorbents

Hollow mesoporous carbon spheres with magnetic cores are directly replicated from hollow mesoporous aluminosilicate spheres with hematite cores by a simple incipient-wetness impregnation technique. The amount of magnetic cores and the saturation magnetization value can be easily tuned by changing the concentration of iron nitrate solution used in the synthesis procedure. As-prepared hollow mesoporous carbon spheres with magnetic cores are used as separable bilirubin adsorbents and show very good adsorptive properties. The characteristics of as-prepared composites are examined by XRD, N(2) sorption, TEM, vibrating-sample magnetometry, and UV/Vis spectroscopy.

Selective Deposition of Iron Oxides Thin Layers on Si(100) from Aqueous Solutions

o C for 1 h. A solution of OTS in anhydrous hexane (10 mM) was used as an ink and applied to the stamp using a spinner at 3000 rpm for 30 s. The inked stamp was placed in contact with Si and held in place for 30 seconds, yielding OTS thin films with approximately 30 A mass coverage. 10 Fe(NO3)3·9H2O and FeCl3·6H2O were used as starting ma- terials to produce hematite and akaganeite, respectively. The hematite thin films were deposited from a 0.05 M iron nitrate solution. The akaganeite thin film was deposited from 0.05 M iron chloride in 0.1 M acetate buffer solution. The OTS-pat- terned Si substrates were immersed in the solution for 2 h at 75 o C with constant stirring. The final pH range of the iron nitrate and iron chloride-acetate buffer solutions was 1.5 ~ 1.7 and 2.5 ~ 3.0, respectively. The color of the nitrate and chloride solutions was red-brown and light ochre, respectively. Both precipitates and thin films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Figure 1(a) and (c) show SEM images of the precipitates and thin film prepared in Fe(NO3)3 solution. The deposited thin film was densely covered with hematite nanoparticles with spherical shapes with an average size of 20 - 50 nm. XRD of both the powder and film showed three predominant peaks at 33.2, 35.6, 65.4° 2θ, which were assigned to (104), (110) and (214) for the hematite phase.

Characterization of nanostructured magnetite thin films produced by sol–gel processing

Nanocrystalline films of magnetite have been prepared by a novel sol–gel route in which, a solution of iron (III) nitrate dissolved in ethylene glycol was applied on glass substrates by spin coating. Coating solution showed Newtonian behaviour and viscosity was found as 0.0215 Pa.s. Annealing temperature was selected between 291 and 350 °C by DTA analysis in order to obtain magnetite films. In-plane grazing angle XRD and TEM studies showed that magnetite phase was present upon annealing the films at 300 °C. The films had crack free surfaces and their thicknesses varied between ~10 and 200 nm. UV–Vis spectrum results showed that transmittance of the films increases with decreasing annealing temperature and increasing spinning rate. Up to 96% transmittance was observed between the wavelengths of 900–1,100 nm. Vibrating sample magnetometer measurements indicated that magnetite thin films showed ferromagnetic behavior and the saturation magnetization value was found as ~35 emu/cm3.

Impedance Response of Franklinite Films to Humidity and Propane

Iron-Zinc oxide films were deposited by the well known ultrasonic spray pyrolysis method from an aqueous solution of iron nitrate and zinc acetate ([Zn]/[Fe] = 0.30). A Franklinite structure of these films turned out from XRD measurements. Additional basic characterization with UV-Vis and infrared spectroscopies and AFM was also performed. Electrical measurements under a small alternating current signal (15 mV RMS) were performed under dry air, humid air (53 % R:H.) and humid air plus propane. Frequency scans yielded sensitivities as high as 260% to humidity and  475% to propane at 30 °C. At 250 °C lower sensitivities were obtained, but in all cases the highest values came from the reactive response of the film. From dynamical response measurements, the response time was also assessed. The mechanisms of sensing are discussed as well.

Nanocomposites materials generated from a spray

The Spray Pyrolysis (SP) process has been employed at moderate temperature (470-970 K) for the synthesis of micro- and nano-particles of hydrated metal oxides and of related nanocomposites. It has been applied to iron nitrate solutions, without or with the addition of sodium chloride as a flux. After removal of the flux, nanocomposites of ferrihydrite (5Fe2O3,9H2O) / hematite (a- Fe2O3) / and an amorphous Fe2O3 are obtained, with surface area 140 m 2 /g. It has been applied also to a sol of Aluminum-tri-sec-butoxide, without or with activation by europium or terbium ions. Boehmite (g-AlOOH) powders are synthesized at 470 K, with surface area equal to 180 m 2 /g. Transition alumina ( g-Al2O3) are synthesized at 970 K. Nanocomposites made by reaction of the boehmite or g-Al2O3 particles with the amino acid asparagin (ASN) have been prepared and characterized. The luminescence of the Eu 3+ or Tb 3+ doped nanocomposites has been investigated: they can be considered as bio-compatible luminescent nanoparticles.

Opal-Hematite and Opal-Magnetite Films: Lateral Infiltration, Thermodynamically Driven Synthesis, Photonic Crystal Properties

Hematite (α-Fe2O3) was infiltrated into opal film pores without depositing the oxide onto the outer film surface by the developed method of lateral infiltration of an aqueous solution of iron nitrate under capillary forces. The thermodynamically driven syntheses of either Fe3O4 (magnetite) or α-Fe were performed in the opal pores using α-Fe2O3 as a precursor. The opal-α-Fe2O3 and opal-Fe3O4 films were characterized by scanning electron microscopy, X-ray diffraction, reflectance, and transmittance measurements. The photonic band gap red-shifted gradually as the number of lateral infiltration runs increased. The maximum filling degrees both of opal-α-Fe2O3 and of opal-Fe3O4 films, calculated from the reflection spectra, appeared to be similar and equal to ∼55% of the pore volume because of very close values of molar volumes of the oxides. It was found that the reversible chemical transformation of fillers in opal pores α-Fe2O3 ↔ Fe3O4 ↔ α-Fe2O3 changes only the filler dielectric constant but does not practi...

Supercapacitive properties of spray pyrolyzed iron-added manganese oxide powders deposited by electrophoretic deposition technique

Nanocrystalline iron-added manganese oxide powders were prepared by spray pyrolysis (SP) from manganese acetate and iron nitrate solutions at 400 °C. The as-obtained powders were subsequently deposited onto graphite substrates via an electrophoretic deposition technique (EPD). The as-prepared powders were examined by transmission electron microscopy (TEM) and X-ray diffractometry (XRD); the electrochemical properties of the coatings were further examined by cycling voltammetry (CV). Structural investigation by TEM and XRD revealed that the as-deposited coatings exhibited Mn 3O 4 phase with nanocrystalline structure. CV examinations showed that the iron addition significantly improved the electrochemical properties of the Mn-oxide powder coatings. The specific capacitance of as-deposited Mn-oxide coating was increased from 202 F/g to 232 F/g when 2 at.% of iron was added. Even after 1200 cycles of life test, the iron-added coatings exhibited higher cycling efficiency (~ 78% of the initial maximum capacitance) than that unadded one (~ 60% of its maximum value).

Characteristics of Hydrothermally Deposited Nanostructured (NiZn) Fe2O4 Films

This work is devoted to the hydrothermal deposition of nanostructured (NiZn) Fe2O4 films on PCB substrates and their structural, morphological and electro-magnetic characterisation. Ferrite films were prepared by the hydrothermal treatment of iron, nickel and zinc nitrate solutions in the presence of reduced iron powder and urea at a temperature of 150 degrees C for 2 hrs. The resulting films with a black appearance are homogeneous without visible pores. The film formed is polycrystalline with a spinel structure and a thickness of about 1.5 microm. Characterisation of the films by a variety of techniques showed that their magnetic and electrical properties are comparable to those of films prepared by other methods reported in the literature.