Samarium Nitrate Research Articles

Nitrates of cerium and samarium deposit on human enamel independently of a salivary pellicle.

The aim of this study was to analyze the precipitation of Cerium(III)nitrate hexahydrate [Ce(NO3)3] or Samarium(III)nitrate hexahydrate [Sm(NO3)3] solutions on human enamel with and without a salivary pellicle. Investigated parameters were At%Ce and At%Sm measured using energy dispersive x-ray spectroscopy (EDX) after test solution (two concentrations) application. Precipitation of Ce(NO3)3 and Sm(NO3)3 solutions was examined on human enamel with and without a salivary pellicle. 6 enamel specimens each were obtained from 12 freshly extracted human third molars. These specimens were ground flat and polished. A salivary pellicle was created on 3 of the 6 specimens per tooth by storing the samples in human saliva. Subsequently, an aqueous solution of Ce(NO3)3 was applied to 2 of the 6 specimens (one with, one without salivary pellicle) for 60 s. The same was carried out with an aqueous solution of Sm(NO3)3 on 2 further specimens. The remaining 2 specimens from each tooth were treated with demineralized water (negative control). Ce(NO3)3 and Sm(NO3)3 solutions were applied at 25 or 50 wt% (aqueous solutions). The test materials and concentrations were distributed using a randomization table. After 60 s exposure and rinsing with demineralized water, the elemental composition (Ce, Sm, Ca, P, O, N, Na, Mg) of the enamel surface was analyzed by EDX. Atomic percentages (At%), differences (ΔAt%) and calcium/phosphorous-ratios (Ca/P-ratios) were calculated and analyzed non-parametrically (α = 0.05). 2.0-2.3 At%Ce (median) was detected on Ce(NO3)3-treated enamel and 0.4-0.7 At% Sm (median) was detected on Sm(NO3)3-treated enamel. Ce was only detected on the surfaces after application of Ce(NO3)3, Sm only after application of Sm(NO3)3. The Ca/P-ratio was significantly lower (1.37-1.59; p = 0.028) after the application of 25% and 50%Ce(NO3)3 as well as 50%Sm(NO3)3 compared to the control treatment (demineralized water; 1.61-1.63). After treatment with Ce(NO3)3, At%Ca and At%Na were significantly lower (p ≤ 0.043) compared to treatment with Sm(NO3)3. No significant differences were found between specimens treated with 25% or 50% lanthanide nitrate solution. Presence of a salivary pellicle had no significant influence on the measured At% with the exception of specimens treated with 50% Sm(NO3)3 with increased At%Sm (p ≤ 0.046). Ce(NO3)3 and Sm(NO3)3 precipitate on human enamel independently of the presence of a salivary pellicle.

Cerium- and samarium-nitrate interaction and accumulation on human dentin

ObjectiveTo investigate the accumulation of cerium-nitrate and samarium-nitrate on dentin without or with smear-layer and to test their antibacterial activity. Design24 dentin-enamel slices were cut from 24 extracted molars. 12 slices underwent smear-layer creation (320 grit, 200 g, 5 s), the other 12 smear-layer removal (20 % EDTA, 300 s). Slices were halved to 48 semilunar-shaped specimens. One specimen per tooth was treated with either Ce(NO3)3 (50 wt% aqueous solution; pH = 1.29; n = 6) or Sm(NO3)3 (50 wt% aqueous solution; pH = 1.88; n = 6). The other specimen served as control (A. demin). After water rinsing, elemental composition (Ce, Sm, Ca, P, O, N, Na, Mg, C) was measured (EDX; EDAX Octane-Elect, APEX v2.5, low-vacuum) in dentin. Atomic percent (At%), Ca/P- and Ca/N-ratios were calculated and analyzed non-parametrically (α = 0.05, error rates method). Additionally, antibacterial activity (2 min exposure) of Ce(NO3)3 and Sm(NO3)3 against Streptococcus mutans, Actinomyces naeslundii, Schaalia odontolytica, and Enterococcus faecalis was determined (colony forming units) after anaerobic incubation at 37 °C for 24 h (control: 0.2 % CHX). ResultsAt% (median) of Ce and Sm were as follows: Ce(NO3)3 3.4 and 0.9 At%Ce with and without smear-layer, respectively; Sm(NO3)3 2.4 and 1.3 At%Sm with and without smear-layer, respectively. Ce(NO3)3 and Sm(NO3)3-application significantly decreased Ca/P-ratios (1.22 – 1.45; p ≤ 0.02) compared to controls (1.47 – 1.63). With smear-layer, significantly higher Ca/N-ratios (5.1 – 29.3) could be detected across all groups (p ≤ 0.004) compared to specimens without smear-layer (0.37 – 0.48). Ce(NO3)3 and Sm(NO3)3 showed reduction rates of up to ≥ 5 log10 steps for S. mutans, A. naeslundii, and S. odontolytica. ConclusionsCerium and samarium nitrate showed accumulation on dentin and certain antibacterial activity and could therefore be identified as potential compounds to treat and prevent dentin and root caries and dentin hypersensitivity.

Extraction Equilibria in the Samarium Nitrate–Nitric Acid–Water–Di(2-ethylhexyl)phosphoric Acid–Organic Diluent System

Extraction Equilibria in the Samarium Nitrate–Nitric Acid–Water–Di(2-ethylhexyl)phosphoric Acid–Organic Diluent System

Electrodeposition behaviour of samarium in 1,3-dimethyl-2-imidazolidone solvent

Abstract The present study investigates the electrochemistry spectroscopy of Sm(III), and electrodeposition of samarium metal in neutral ligand-based ionic liquid (solvate ionic liquid). Mixture consisted of a samarium precursor (either samarium triflate or samarium nitrate hexahydrate) in the solvate ionic liquid, 1.3-dimethyl-2-imidazolidone (DMI). FT-IR analysis of Sm(III)-DMI electrolytes indicates that Sm3+ ion coordinates with DMI through carbonyl group (C=O); the band splits into two with emergence of new peak at 1630 cm−1 and 1649 cm−1 for the triflate and nitrate solutions, respectively. Raman spectroscopy also confirms the solvation of Sm(III) with DMI through oxygen atom of the carbonyl group. Voltametric behaviour of Sm(III) ion indicates two-step reduction mechanism via Sm(III)/Sm(II) at ca. −2.0 V and Sm(II)/Sm(0) at ca. −3.0 V vs. Ag/Ag+ for both samarium(III)-containing electrolytes. Diffusion coefficient value of Sm(III) was determined to be 2.185 × 10−6 cm2/s and 2.418 × 10−8 cm2/s for triflate and nitrate electrolytes, respectively. Electrodeposition of samarium was achieved through constant potential electrolysis using copper substrate as the working electrode which yielded compact deposits from triflate-DMI and non-uniform granular deposit from nitrate-DMI electrolyte. Ex situ X-ray photoelectron spectroscopy analysis of the as-deposited samples revealed the presence of metallic Sm (1081 eV) co-existing with its oxide form (1083 eV).

A novel strategy for the synthesis of samarium/europium-metal organic frameworks, and their utilization for detection of Cr3+, Pb2+, and acetone as a luminescent sensor with superior selectivity and sensitivity properties

With outstanding detection selectivity and sensitivity characteristics, samarium/europium-metal organic frameworks (Sm/Eu-MOF) is capable of functioning as a versatile light-emitting sensor particularly for detecting acetone, Cr3+, and Pb2+ in aqueous environment. While considering maximum detectable concentrations of 0.85 μM, 0.46 μM, and 1.04 μM, respectively, competitive energy interactions for acetone, absorption of energy for Cr3+, and substitution of ions for Pb2+ are the elucidated mechanisms of detecting these substances by Sm/Eu-MOF. Successful formulation and synthesis of a core–shell structured Sm/Eu-MOF, which has endurance to acid/alkali conditions and hydration/heat-stability, can be accomplished by utilizing Samarium and Europium nitrate ions, terephthalic acid, and 2, 5-furandicarboxylic acid. The recovery rate of acetone, Cr3+, and Pb2+ detection from real samples were 95.0–101.0 %, 99.8–101.0 %, and 99.9–104.0 %, respectively.

Compton scattering geometry: a tool to study radiation interaction characteristics of rare earth compounds doped in low-Z organic compound

Abstract The present measurements comprise of Compton scattering technique at six energies from 0.242 MeV to 0.402 MeV (not available from conventional radioisotopes) by scattering of primary gamma photon beam of 0.662 MeV energy from cylindrical aluminium target at different scattering angles. Two inorganic (rare-earth) compounds, Lanthanum (3+) nitrate hexahydrate and Samarium (3+) nitrate hexahydrate in a Low-Z organic solvent (acetone), have shown certain radiation interaction characteristics are the subject of study. The collimated beam of scattered gamma rays impinges on the plastic container having solution of rare earth compounds in the acetone of different concentrations. The transmitted gamma ray beam is detected by a well-collimated 2″ × 2″ NaI(Tl) scintillation detector and is analysed by a PC-based ORTEC Mastero-32 MCA. Attenuation coefficients along with some shielding parameters i.e. molar extinction coefficients, half value layer, tenth value layer and mean free path are evaluated. Besides this, Computed Tomography numbers and photon interaction cross-sections (photoelectric, coherent and incoherent) are also determined. The measured values of these parameters are compared with WinXCom software package’s values and are found to be in good agreement. The available data on rare earth salts’ solutions, in the current measurements, is scientifically important in nuclear and radiation physics, bridging the gap in which radiation workers do not have access to such data.

Recyclization reaction of <i>S</i>-, <i>N</i>-containing cyclic peroxides with aromatic amines

The recyclization reaction of tetraoxathiaspiroalkanes and tetraoxathiocanes with primary amines ( o , p -fluoroanilines, m , p -chloroanilines, o -toluidine, o , p -anisidines, ammonium chloride) to obtain cycloazadiperoxides under the action of samarium nitrate crystal hydrate as a catalyst was studied. The possibility of recycling N -( tert -butyl)hexaoxaazadispirocycloalkanes with arylamines to the corresponding azatriperoxides was shown. It was found that the rate of the recyclization reaction depends on the nature of the central heteroatom in the heterocycle (S > N > O).

Radiation Interaction Characteristics of Solutions of La(NO3)3.6H2O and Sm(NO3)3.6H2O in Acetone Using Compton Scattering Technique

This work deals with the evaluation of interaction cross sections, effective atomic number, and effective electron density at gamma photon energies, not available from standard radioisotopes. The Compton scattering technique is used to obtain the required gamma energies within a specific range of energies from 241.8 to 401.8 keV to perform the radiation measurements. Radiation interaction parameters of some inorganic compounds (high-Z rare-earth nitrate hexahydrate), namely, Lanthanum(III) nitrate hexahydrate [La(NO3)3.6H2O] and Samarium(III) nitrate hexahydrate [Sm(NO3)3.6H2O], soluble in low-Z organic solvent (acetone) are evaluated. Six scattering angles are chosen to obtain six (not available from standard radioisotopes) Compton scattered energies to perform narrow-beam transmission experiments. An NaI(Tl) scintillation detector is used to detect the transmitted flux from the different solutions in various proportions. Photon interaction parameters useful in vast basic and applied fields are evaluated. The present measured results, obtained from the Compton scattered technique, are found to be in good agreement with the computed values of radiation interaction parameters obtained from the WinXCom program. The present data on rare-earth solutions have definite scientific importance in nuclear and radiation physics and fill in the gap of nonavailability of such data for radiation workers at these specific energies.

Preparation of SmCoO3 by Sol-Gel Method and Its Photocatalytic Activity

Using citric acid (C6H8O7·H2O), samarium nitrate (Sm(NO3)3·6H2O) and cobalt nitrate (Co(NO3)3·6H2O) as main raw materials, the SmCoO3 samples were successfully prepared by sol-gel method. The prepared samples were characterized by thermogravimetry and differential scanning calorimetry (TG-DSC), X-ray diffractometer (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Using azo dye methyl orange solution as the simulated sewage, the photocatalytic activity of SmCoO3 samples was explored at different synthesis temperatures and illumination times. The experimental results show that pure SmCoO3 samples can be prepared at a calcination temperature of 600 °C to 1000 °C. Under ultraviolet light conditions, the sample of SmCoO3 calcined at 800 °C has the best photocatalytic activity. When illumination times is 120 min, the degradation rate of methyl orange of 10 mg/L can reach more than 97%, and SmCoO3 shows good photocatalytic performance.

Hydrothermal Syntheses of Uranium Oxide Hydrate Materials with Sm(III) Ions: pH-Driven Diversities in Structures and Morphologies and Sm-Doped Porous Uranium Oxides Derived from Their Thermal Decompositions.

We report the hydrothermal syntheses of three uranyl oxide hydroxy-hydrate (UOH) materials containing Sm(III) ions (UOH-Sm) by controlling the solution pH and a new way to make Sm-doped porous uranium oxides with different U-to-Sm atomic ratios via their thermal decompositions. While layer-structured UOH-Sm phases with U-to-Sm atomic ratios of 1 (UOH-Sm1) and 4 (UOH-Sm2) were obtained from the reaction of schoepite and samarium nitrate with final solution pH values of over 4, similar reactions without pH adjustment with final solution pH values of less than 4 led to the formation of a uranyl oxide framework (UOF-Sm) with a U-to-Sm atomic ratio of 5.5. The crystal structure of compound UOF-Sm was revealed with synchrotron single-crystal X-ray diffraction and confirmed with transmission electron microscopy. The two-dimensional uranyl oxide hydroxide layers, similar to that for β-U3O8, are linked by double pentagonal uranyl polyhedra to form a three-dimensional framework with Sm(III) ions in the channels. Scanning electron microscopy characterization revealed nanoplate crystal morphologies for the two UOH-Sm phases, in contrast to the needle morphology for UOF-Sm. Subsequent thermal treatments led to the formation of Sm-doped uranium oxides, maintaining the original crystal shapes and U-to-Sm ratios but with nanopores. This work demonstrated that the hydrothermal synthesis conditions, especially fine-tuning of the solution pH, have a significant impact on the uranium hydrolysis, thus leading to well-defined products. This will facilitate the targeted syntheses of UOH phases with lanthanide (Ln) ions and explore the subsequent applications of these materials and Ln-doped porous uranium oxides as potential nuclear or functional materials.

Fabrication of Sm2O3 nano-particle – Transparent urethane resin composite films and its PL properties

Using a solution of samarium nitrate and ethanol and a UV-curable liquid urethane resin as starting materials, we fabricated samarium (III)oxide (Sm2O3) nanoparticle-based composite films. The color of the films turned from yellow (of the precursor) to reddish orange after being cured by UV irradiation. The particle size of the Sm2O3 in the composite film were measured using transmission electron microscopy (TEM) and observed to be in the range of 56–86 nm. Moreover, the crystallographic structure of the particles was analyzed via TEM and selected area electron diffraction. The composite film exhibited photoluminescent (PL) properties with a peak at 640 nm (corresponding to the transition 4G5/2 → 6H9/2) upon irradiation with light at a wavelength of 340 nm. Furthermore, upon extended UV light irradiation, some of the trivalent Sm3+ of Sm2O3 particles in the films were reduced to Sm2+, which was confirmed by the PL peaks observed at 683 nm and 731 nm (attributed to the divalent Sm2+).

Characteristics and Photovoltaic Applications of Au-Doped ZnO-Sm Nanoparticle Films.

Au-doped ZnO–samarium nitrate (Sm) nanoparticles with fixed concentrations of Sm (1 wt %) and various concentrations of Au (0.0, 0.5, 1.0 and 1.5 wt %) were prepared and used as photoelectrodes to enhance the photovoltaic efficiency of dye-sensitized solar cells (DSSCs). The cell fabricated with 1.5 wt % of Au-doped ZnO–Sm nanoparticles film achieved an optimal efficiency of 4.35%, which is about 76% higher than that of 0.0 wt % of Au-doped ZnO–Sm-based cell (2.47%). This increase might be due to the formation of a blocking layer at the ZnO–Sm/Au interface, which inhibits the recombination of electrons. This increase may also be attributed to the addition of rare-earth ions in ZnO to enhance the non-absorbable wavelength region of light via up/down-conversion of near-infrared and ultraviolet radiations to visible emission and reduce the recombination loss of electron in the cell. The efficiency of cells may be increased by the blocking layer and up/down-conversion process and thus promote the overall performance of the cells. This work indicates that Au-doped ZnO–Sm nanoparticle films have the potential to increase the performance of DSSCs.

Novel Multifunctional Samarium-Organic Framework for Fluorescence Sensing of Ag+, MnO4 -, and Cimetidine and Electrochemical Sensing of o-Nitrophenol in Aqueous Solutions.

A novel Sm-metal–organic framework (MOF) sensor with the molecular formula Sm8(HDBA)6·H2O has been prepared based on a penta-carboxyl organic ligand (H5DBA = 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid) and samarium nitrate under solvothermal conditions. Sm-MOF is characterized by single-crystal X-ray diffraction analysis, elemental analysis, thermogravimetric analysis, and powder X-ray diffraction analysis. Structural analysis shows that the dimer metal units are alternately connected to form a one-dimensional chain, and this chain is connected by the bridging carboxyl oxygen of the ligand H5DBA to form a two-dimensional double-layer plane, which then expands into a three-dimensional microporous framework. Fluorescence detection studies show that Sm-MOF can detect Ag+ ions, MnO4– anions, and cimetidine tablets with high sensitivity and selectivity and can also be used to electrochemically detect o-nitrophenol in water. High-sensitivity detection capability of the Sm-MOF can enrich the application of samarium complexes in multifunctional sensors.

Samarium-doped ZnO thin films synthesized by Sol-gel: Structural, optical and electrical properties

Zinc oxide thin films doped with various elements are in the spotlight due to their electrical, thermoelectrical, luminescent and transparency in the visible range properties, with multiple applications in optoelectronic devices. In this work, samarium doped zinc oxide thin films were prepared by the Sol-gel technique, from a very simple solution. Only the metal precursors (zinc acetate and samarium nitrate) were dissolved in methanol at room temperature. A completely transparent, homogeneous and stable solution was obtained without the need of additives, stabilizers or catalysts of any kind. Thin films were prepared using a multi-dipping procedure on Corning glass substrates. The doping concentrations were 3 and 5 at.% and the annealing temperature varied from 100 to 500 °C. The films were characterized by XRD, FTIR, UV–Vis and SEM; the thickness and resistivity of the films were also measured. According to the XRD results, all the films are polycrystalline and nanostructured, even when annealed at 100 °C, a considerably low temperature. The electrical properties of the films and their high optical transmission (>80%) in the visible-near IR range, render these nanocrystalline films potential materials for their use in optoelectronic devices. A figure of merit (ϕ) of 3.5 × 10−6 Ω−1 was obtained for the 3 at.% ZnO:Sm films annealed at 400 °C, which also confirmed the beneficial effects of the samarium dopant in the ZnO matrix.

Synthesis, Structures and Properties of Two Ln(III) Coordination Polymers based on Pyrimidine‐2‐carboxylic Acid and Sodium Dicyanamide

AbstractAssemblies of pyrimidine‐2‐carboxylic acid (Hpmc) and samarium nitrate or europium nitrate in the presence of sodium dicyanamide (Na‐dca) under ambient conditions yielded two new coordination polymers, namely [Ln(pmc)2(dca)(H2O)2]n (Ln=Sm (1), Eu (2)). The complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR and fluorescence spectra. Structure analysis shows two complexes are isostructural with monoclinic (C2/c) symmetry. And each central metal atom is coordinated by three chelate pmc−, one terminal dca− and two water molecules to generate an infinite zigzag chain. Through Owater−H ⋅ ⋅ ⋅ Ocarboxylate, Owater−H ⋅ ⋅ ⋅ Npyrimidine hydrogen bonds, the chains are connected to a two‐dimensional net, which is furtherly extended to a three‐dimensional supramolecular structure by Owater−H ⋅ ⋅ ⋅ Ncyano hydrogen bonds. Luminescent measurement of complex 2 shows the characteristic fluorescence of Eu3+.

Effect of the Counterion on Circularly Polarized Luminescence of Europium(III) and Samarium(III) Complexes.

Each enantiopure europium(III) and samarium(III) nitrate and triflate complex of the ligand L, with L = N,N′-bis(2-pyridylmethylidene)-1,2-(R,R + S,S)-cyclohexanediamine ([LnL(tta)2]·NO3 and [LnL(tta)2(H2O)]·CF3SO3, where tta = 2-thenoyltrifluoroacetylacetonate) has been synthesized and characterized from a spectroscopic point of view, using a chiroptical technique such as electronic circular dichroism (ECD) and circularly polarized luminescence (CPL). In all cases, both ligands are capable of sensitizing the luminescence of both metal ions upon absorption of light around 280 and 350 nm. Despite small differences in the total luminescence (TL) and ECD spectra, the CPL activity of the complexes is strongly influenced by a concurrent effect of the solvent and counterion. This particularly applies to europium(III) complexes where the CPL spectra in acetonitrile can be described as a weighed linear combination of the CPL spectra in dichloromethane and methanol, which show nearly opposite signatures when their ligand stereochemistries are the same. This phenomenon could be related to the presence of equilibria interconverting solvated, anion-coordinated complexes and isomers differing by the relative orientation of the tta ligands. The difference between some bond lengths (M–N bonds, in particular) in the different species could be at the basis of such an unusual CPL activity.

Synthesis and photoluminescence properties of nanoporous anodic aluminum oxide (NAAO): Sm3+ nanocomposite layer: Effect of anodizing parameters (time and voltage), Sm3+ concentrations, and annealing temperatures

In the present work, nanoporous anodic aluminum oxide (NAAO) layers were synthesized by mild and mild-hard anodization methods in a solution of oxalic acid and photoluminescence properties of these oxide layers were compared. Then, the nanoporous anodic aluminum oxide: Sm3+ (NAAO: Sm3+) nanocomposite layer is produced by boiling the NAAO layers in a solution of samarium nitrate and annealing at different temperatures under argon atmosphere. Moreover, effect of anodizing parameters (time and voltage), Sm3+ concentrations, and annealing temperatures on photoluminescence properties of the NAAO: Sm3+ nanocomposite layers were investigated and results indicate composition of SmAlO3. Finally, morphology, phase structure, energy levels, and emission wavelengths of the oxide layers were investigated by field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), and photoluminescence (PL) spectroscopy. Results indicate that the PL intensity of the NAAO layers produced by mild-hard anodization is more than the mild anodization. Moreover, the layers produced at 120 V for 2 h have the most PL intensity. At 1200 °C temperature, 0.7 M concentration of samarium ions the most PL intensity is created. Moreover, with the excitation of the NAAO: Sm3+ nanocomposite layer created at 400 nm wavelength, three main emission bands from the 4f-4f intra-configuration transitions from Sm3+ ions are clearly observed. These transitions include 4G5/2 → 6H5/2, 4G5 2 → 6H7/2, and 4G5/2 → 6H9/2.

Synthesis and Characterization of [Sa(p-anisal-DA)4(H2O)2]by insitu Method

The insitu synthesis of Schiff base metal complex using N-phenyl-1,4-phenylenediamine (DA), p-anisaldehyde (p-anisal) as starting materials with samarium nitrate hexahydrate (Sa(NO3)2.6H2O) as a metal precursor in the molar ratio (1:1:1 M) at room temperature. The prepared metal complex is washed with several times with ethanol and boiled water for the removal of un-reacted starting materials completely. The following techniques are used to confirm the prepared Schiff base metal complex by UV-visible spectroscopy, Fourier Transforms Infrared spectroscopy, X-ray diffraction pattern and Cyclic Voltammetry.

Synergistic corrosion inhibition effects of benzimidazole-samarium (III) molecules on the steel corrosion prevention in simulated seawater

Benzimidazole molecules and samarium nitrate were mixed together to synergistically reduce the steel corrosion rate in simulated seawater solution. Scanning electron microscopy analysis demonstrated that in the solution containing the mixture of inhibitive compounds (especially at 250 ppm Sm+750 ppm BI) a dense film without micro-crack uniformly deposited on the steel surface. The interaction (physical and/or chemical) between the samarium cations and benzimidazole molecules was confirmed by means of Fourier-transform infrared spectroscopy. By polarization and electrochemical impedance spectroscopy techniques, the corrosion inhibition activity of the deposited film on the steel surface was investigated. The electrochemical tests revealed the poor corrosion inhibition activity of each of inhibitors in NaCl solution, but 92% efficiency was attained in mixed form. The polarization test showed that the film of benzimidazole-samarium (III) could effectively retard the cathodic/anodic corrosion reactions on the steel surface in subjection to the chloride-containing electrolyte and decrease the corrosion current density from 8.5 to 0.7 μA/cm2.

Preparation and characterization of NiO based nano-ceramic composites as alternative anode materials for solid oxide fuel cells (SOFCs)

Solid oxide fuel cell (SOFC) is being developed all over the world at present as a future energy conversion device. The alternative anode materials are also being studied in order to develop efficient low temperature SOFCs (LTSOFCs) operating below 800o C. Ni‐based cermets are still the most promising anode materials and some targeted modifications are needed to improve the coking resistance and to enhance their electro-catalytic activity relatively at low temperature (~600 – 700 oC) range. Present work is aimed to develop alternate anode materials such as, NiO-Ce0.9Gd0.1O2-δ-Ce0.9Y0.1O2-δ, NiO-Ce0.8Gd0.2O2-δ-Ce0.8Y0.2O2-δ, NiO-Ce0.9Gd0.1O2-δ-Ce0.9Sm0.1O2-δ, NiO-Ce0.8Gd0.2O2-δ-Ce0.8Sm0.2O2-δ, NiO-Ce0.9Gd0.1O2-δ and NiO-Ce0.8Gd0.2O2-δ for by simple chemical precipitation route and characterize them towards application in SOFC systems. The precursor materials used in this synthesis were cerium nitrate hexahydrate, gadolinium nitrate, yttrium nitrate, samarium nitrate [as basic materials] and sodium hydroxide [as precipitator material]. C-TAB (cetyl trimethylammonium bromide) was used as a surfactant in order to avoid the agglomeration of the nanoparticles. The influence of Gd, Y and Sm doping on the phase structure development of ceria was investigated. The prepared anode materials were characterized by TGA, XRD, FTIR, particle size analysis, SEM and EDAX. The electrical characteristics of the materials were studied by electrochemical impedance spectroscopy. The results obtained were discussed in order to use the materials as alternate anode materials for SOFCs.