Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates

Cizauskaite, Sigute; Kareiva, Aivaras

doi:10.2478/s11532-008-0045-0

Cited by 15 publications

(9 citation statements)

References 67 publications

(71 reference statements)

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“…All the diffraction peaks of samples calcined at 500-700°C are well matched with La 0.7 Sr 0.3 FeO 3 (JCPDS 89-1269), respectively, except a small peak located at 25.2°( 2h) corresponding to SrCO 3 phase (JCPDS 05-0418). This phenomenon was also observed by Karpinski et al [22,23]. Most of the alkaline earth metal oxides and rare earth metal oxides, in particular BaO, SrO, and Re 2 O 3 , contain metal carbonate [24,25].…”

Section: Methodssupporting

confidence: 52%

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

et al. 2014

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La 0.7 Sr 0.3 FeO 3 nanofibers with tunable hollow structures are prepared by a facile single capillary electrospinning and annealing process. The hollow nanofibers are characterized by thermogravimetry and differential thermal analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and nitrogen physisorption isotherms. The tunable hollow structures are controlled by adjusting the weight ratio of (La(NO 3 ) 3 Á6H 2 O ? Sr(NO 3 ) 2 ? Fe(NO 3 ) 3 Á 9H 2 O)/PVP. With the increasing of nitrate/PVP ratio, the diameter and the shell thickness of hollow nanofibers increase. Formaldehyde gas sensing properties are carried out in the concentration range of 0.1-100 ppm at the operating temperature of 240°C. The gas sensing mechanism is also discussed.

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Section: Methodssupporting

confidence: 52%

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

et al. 2014

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“…These findings agree with literature data obtained by X‐ray diffraction. Cizauskaite and Kareiva investigated LSC samples with different Sr‐concentrations also fabricated by a sol‐gel process 37. They demonstrated that a single‐phase perovskite is formed at calcination temperatures between 900 and 1000 °C.…”

Section: Resultsmentioning

confidence: 99%

“…Cizauskaite and Kareiva investigated LSC samples with different Sr-concentrations also fabricated by a sol-gel process. [ 37 ] They demonstrated that a single-phase perovskite is formed at calcination temperatures between 900 and 1000 ° C. At lower temperatures they found the formation of metastable phases like Co 2 O 3 , SrCO 3 [ 38 ] La 2 CoO 4 is also known to be formed if the perovskite-type LaCoO 3 is reduced at high temperatures. [ 39 ] wileyonlinelibrary.com The grayscale histogram of the image stack of sample LSC800 is displayed in Figure 4 c. It shows the voxel frequency in dependence of the grayscale value.…”

Section: Crystalline Phasesmentioning

confidence: 99%

“…Cizauskaite and Kareiva investigated LSC samples with different Sr-concentrations also fabricated by a sol-gel process. [ 37 ] They demonstrated that a single-phase perovskite is formed at calcination temperatures between 900 and 1000 ° C. At lower temperatures they found the formation of metastable phases like Co 2 O 3 , SrCO 3 and SrO. Depending on the used solgel chemistry Co 3 O 4 was found up to 1000 ° C annealing temperature.…”

Section: Crystalline Phasesmentioning

confidence: 99%

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Microstructure of Nanoscaled La_0.6Sr_0.4CoO_3‐δ Cathodes for Intermediate‐Temperature Solid Oxide Fuel Cells

Dieterle

Bockstaller

Gerthsen

et al. 2011

Advanced Energy Materials

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Numerous preparation techniques for perovskite-based MIEC materials have been developed over the last years. Apart from the conventional methods of cathode preparation, including high temperature calcination, mechanical grinding of powders, screen printing and sintering of thick fi lm layers, alternative synthesis and deposition routes are available. Nanocrystalline LSC or La 1−x Sr x Co 1−y Fe y O 3− δ thin fi lms on electrolyte substrates were already fabricated by pulsed laser deposition, [6][7][8][9] DC, and RF sputtering, [ 10,11 ] spray pyrolysis, [ 12 ] and sol-gel deposition. [13][14][15][16][17] In this work the chemical and structural properties and the stability of nanoscaled La 0.6 Sr 0.4 CoO 3− δ LSC thin fi lm cathodes on polycrystalline Gd 0.1 Ce 0.9 O 1.95 (CGO) substrates were investigated thoroughly. The fabrication by a low-temperature sol-gel technique is favorable for tailoring the grain size, porosity and cathode-fi lm thickness. [ 18 ] The electrochemical properties of the nanoscaled LSC thin fi lm cathodes were already reported by Hayd et al. who presented an outstanding electrochemical performance and extraordinary low area specifi c resistances as low as ASR chem = 0.023 Ω cm 2 at an operating temperature of 600 ° C. [ 19,20 ] Interestingly enough, theoretical models predicted ASR chem values up to one order of magnitude larger than the experimental data. For obvious reasons, the excellent performance of our nanoscaled cathodes does not solely depend on microstructure (porosity, increased inner surface area) as reported in previous work, [ 21 ] but presumably on the enhanced catalytic properties of the La 0.6 Sr 0.4 CoO 3− δ . However, the outstanding electrochemical performance motivates the analysis of the microstructure and phase composition of the LSC cathodes presented in this work.The nanoscaled LSC thin-fi lm cathodes were studied by transmission and scanning transmission electron microscopy (TEM/STEM) combined with energy-dispersive X-ray spectroscopy (EDXS). Moreover, high-angle annular dark-fi eld (HAADF) STEM tomography was used to study the distribution of the pores and quantify the porosity, which was not reported for nanoscaled (La,Sr)CoO 3 -based materials in literature before. Although several techniques like μ -tomography, [ 22 ] FIB-tomography, [ 23,24 ] transmission X-ray microscope based X-ray tomography, [ 12 , 25 ] mercury intrusion, [ 22 , 26 ] nitrogen adsorption, [ 27 ] or the Archimedes method [ 22 , 28 ]

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“…A number of approaches such as solid-state reactions (Zhou et al, 2006), mechanical-synthesis (Szabo et al, 2002), coprecipitation (Nakayama et al, 2003;Srdic et al, 2005), solution combustion or thermal decomposition (Bansal and Zhong, 2006;Berger et al, 2004;Berger et al, 2007) hydrothermal, and sol-gel technique (Pechini, 1967;Cizauskaite and Kareiva, 2008) have been used to synthesize LaMO 3 -based perovskite powders. The solgel method is highly attractive because various metal ions are chelated to form metal complexes in solution and are uniformly distributed at the molecular level.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Evaluation Catalytic Efficiency of Perovskite-Type Oxide Nanopowders in Removal of Bromocresol Purple from Aqueous Solution

Tavakkoli¹,

Ghaemi²,

Mostofizadeh³

2014

IJSRK

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Abstract. A 1-x A x BO 3 belongs to the perovskite oxides of the ABO 3 structure. In this study, nanoparticles of La 0.5 Ca 0.5 FeO 3 were fabricated by sol-gel citrate technique. A series of common analytical techniques were used to characterize the crystallinity, morphology, specific surface area, and grain size of the nanopowders. These properties were characterised by means of XRD, SEM, EDX and FTIR. The calculated particles size using the Scherrer's formula was about 20 nm. Moreover, the family of perovskite-type oxides could be considered as an adsorbent/catalyst material for the removal of dyes. This study has also investigated the efficiency of La 0.5 Ca 0.5 FeO 3 , as an adsorbent for removal of dye (Bromocresol Purple (BP)), from an aqueous solution. The adsorption studies were carried out at different pH values, various adsorbent dosages and contact time in a batch experiments. The kinetic studies indicate that the removal process obeys the Pseudo-first-order kinetic equation. Also, the isotherm evaluations reveal that the adsorption of BP by the nanoparticles follows the Langmuir model. In addition, this nanoparticle with good specific affinity towards dye molecules was a promising adsorbent for dye removal from natural water.

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Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates

Cited by 15 publications

References 67 publications

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

Microstructure of Nanoscaled La_0.6Sr_0.4CoO_3‐δ Cathodes for Intermediate‐Temperature Solid Oxide Fuel Cells

Synthesis and Evaluation Catalytic Efficiency of Perovskite-Type Oxide Nanopowders in Removal of Bromocresol Purple from Aqueous Solution

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Sol-gel preparation and characterization of non-substituted and Sr-substituted lanthanum cobaltates

Cited by 15 publications

References 67 publications

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

Direct fabrication of La0.7Sr0.3FeO3 nanofibers with tunable hollow structures by electrospinning and their gas sensing properties

Microstructure of Nanoscaled La0.6Sr0.4CoO3‐δ Cathodes for Intermediate‐Temperature Solid Oxide Fuel Cells

Synthesis and Evaluation Catalytic Efficiency of Perovskite-Type Oxide Nanopowders in Removal of Bromocresol Purple from Aqueous Solution

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Microstructure of Nanoscaled La_0.6Sr_0.4CoO_3‐δ Cathodes for Intermediate‐Temperature Solid Oxide Fuel Cells