Fabrication of Porous LSCF-SDC Carbonates Composite Cathode for Solid Oxide Fuel Cell (SOFC) Applications

2011 ◽  
Vol 471-472 ◽  
pp. 179-184 ◽  
Author(s):  
Raharjo Jarot ◽  
Andanastuti Muchtar ◽  
Wan Ramli Wan Daud ◽  
Norhamidi Muhamad ◽  
Edy Herianto Majlan

Composite cathodes made of perovskite La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) and SDC carbonates (SDC-(Li/Na)2CO3) were investigated in relation to their structure, morphology, thermal expansion coefficient and porosity. As a first step, the LSCF powder was prepared by sol-gel technique. This was followed by the preparation of the LSCF-SDC carbonates composite cathode by mixing the LSCF with SDC-(Li/Na)2CO3 electrolyte via solid state reaction in various compositions, i.e. 30, 40 and 50 wt.%, namely 70LSCF-30SDC7030, 60LSCF-40SDC7030 and 50LSCF-50SDC7030, respectively. The powder mixtures were then calcined at 680oC. The resultant powder was fine with surface area of about 3.39-7.42 m2/g and particle size of 0.56-0.66µm. The powder consists of two distinct phases, i.e. LSCF and SDC-(Li/Na)2CO3 as confirmed with x-ray diffraction. The microstructures were observed under scanning electron microscopy (SEM). Increasing the amount of the SDC-(Li/Na)2CO3 electrolyte in the composite cathode was found to bring the thermal expansion of the cathode closer to that of the electrolyte. The cathode pellets were later compacted at different pressures (27, 32 and 37 MPa) and sintered at 600oC. The optimum porosity (20.99-24.98%) was achieved for samples with SDC-(Li/Na)2CO3 content of 30-50% sintered at 600oC and cold pressed at 37 MPa.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bamba Mahman ◽  
Mpho Enoch Sithole

A series of undoped mixed-phase BaAl2O4/CaAl4O7 (hereafter called BC) and doped BC: x% Eu3+ (0 < x ≤ 5.5) nanophosphors were successfully prepared by the citrate sol-gel technique. Their structure, morphology, and optical properties were studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD and SEM showed that all the BC:x% Eu3+ samples consisted of the crystalline structure of the mixed phases of both the BaAl2O4 and CaAl4O7 materials. The structure resembles more that of the BaAl2O4 than the CaAl4O7 phase. The TEM results suggest that the crystallite sizes are in the nanometer scale with rod-like particles. PL results showed multiple emission peaks located at 436, 590, 616, 656, and 703 nm, which were assigned to the intrinsic defects within the BC matrix, 5D0 ⟶ 7F1, 5D0 ⟶ 7F2, 5D0 ⟶ 7F3, and 5D0 ⟶ 7F4 transitions of Eu3+, respectively. The decay curves evidently showed that the nanophosphors have persistent luminescence. The Commission Internationale de l’Eclairage (CIE) analysis revealed that doping has tuned the emission colour from blue to orange-red. The results indicate that the Eu3+-doped samples can potentially be used in the orange/red-emitting phosphors.


2010 ◽  
Vol 177 ◽  
pp. 257-259
Author(s):  
Shu Fang Zheng ◽  
Guo Xuan Xiong ◽  
Hai Qing Huang ◽  
Liu Jun Luo

Nano-porous Barium ferrite (BaFe12O19) nanoparticles were synthesized by sol-gel technique using CTAB as template. The structure, morphology, and magnetic properties of samples were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results show that particles size are about 45 nm to 65 nm. And the nanoparticles show a saturation magnetization (Ms) of 62.831 emu/g, a coercivity (Hc) of 5481.0 Oe and a remament magnetization (Mr) of 33.083 emu/g.


High purity barium titanate BaTiO3 was successfully synthesized by using the sol-gel technique. Barium acetate Ba(CH3COO)2 and tetrabutyl titanate, Ti(C4H9O)4 was dissolved moderately in the solvent of glacial acetic acid and ethanol was added as the chemical modifier. The synthesized BaTiO3 nanoparticle was calcined at the temperature range of 700 ºC to 1100 ºC. The powders were further characterized by X-ray diffraction and scanning electron microscopy (SEM). Fined BaTiO3 powders result indicates the phase of tetragonal structures and high crystallites of BaTiO3. It was observed that the crystallinity and particle size of BaTiO3 is greatly influenced by the calcination temperature.


2017 ◽  
Vol 89 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Elena Asabina ◽  
Vladimir Pet’kov ◽  
Pavel Mayorov ◽  
Dmitriy Lavrenov ◽  
Igor Schelokov ◽  
...  

AbstractThe phosphates M0.5+x M′x Zr2−x (PO4)3 (M–Ca, Mn, Co, Sr, Cd, Ba, Pb; M′–Mg, Mn, Co) were synthesized by sol-gel method with the following thermal treatment of reaction mixtures. X-ray diffraction, IR spectroscopy and electron microprobe analysis showed that the obtained phosphates crystallized in Sc2(WO4)3 (SW) and NaZr2(PO4)3 (NZP) structural types. Both types of crystal structures are based on a framework comprised of octahedra and tetrahedra, the difference between them is fragments orientation. Thermal expansion of the phosphates was studied in the temperature range 20–800°C. Some compounds were found to belong to low-expanding materials (αav ~2·10−6°C−1).


2018 ◽  
Vol 34 (6) ◽  
pp. 3140-3144
Author(s):  
Ritu Vershney ◽  
Komal Chelaramani ◽  
Arpan Bhardwaj ◽  
Nayma Siddiqui ◽  
Suresh Kumar Verma

The synthesis of Ni doped titania (TiO2) nanoparticles were achieved via simple novel sol gel technique, in which Titanium-n-butoxide and NiCl2 were taken as precursors. Effect of different wt% of dopant in TiO2 was studied on photocatalytic degradation of Aniline blue and Toluidine Blue. The study suggested the increased photocatalytic degradation with increased time duration. The synthesized samples were analyzed by surface electron microscopy (SEM) and X-ray diffraction studies. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus bacteriae. Studies revealed that on increasing the dopant concentration, the diameter of zone of inhibition also increased upto 1.5 wt%.


1998 ◽  
Vol 541 ◽  
Author(s):  
M. Linnik ◽  
O. Wilson ◽  
A. Christou

AbstractThe preparation and characterization of thick PLZT films for spatial phase modulator applications are reported. Films were fabricated on LSCO/LAO substrates by a sol-gel technique using multiple heat-treatment parameters. The crystal quality of PLZT 9/65/35 films was investigated by X-ray diffraction and scanning electron microscopy.


2017 ◽  
Vol 907 ◽  
pp. 56-60
Author(s):  
Ummuhanı Hilal Özer ◽  
Kerim Emre Öksüz ◽  
Ali Özer

It is well known that sol-gel technique is a simple method to produce nano sized ceramic powders. In this study, cerium oxide doped zirconia samples, with 10 mol%-12mol% and14mol% CeO2, were synthesized by sol-gel technique and characterized. The surface morphology, elemental composition, microstructure, and phase analysis, of the sintered CeO2 doped ZrO2 ceramics were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDS) analysis, and X-ray diffraction (XRD) respectively. X-ray diffraction for samples sintered at 1550 °C for 4h revealed that the zirconia ceramics have a tetragonal phase structure. The addition of CeO2 can raise the content of the tetragonal phase, but the minor monoclinic phase exists even at the CeO2 content of 10 mol%. The effect of dopant concentration on the lattice parameter, average primary crystallite size and micro-strain was studied. Relative densities for CeO2 doped ZrO2 bulk ceramics varied between 95% and 99 %, depending on the CeO2 addition.


2019 ◽  
Vol 51 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Srdjan Perisic ◽  
Marija Vuksanovic ◽  
Milos Petrovic ◽  
Andjela Radisavljevic ◽  
Aleksandar Grujic ◽  
...  

Hybrid composite panels of Wood-Plastic Composites (WPC) consisting of wood and poly (methyl methacrylate) (PMMA) were reinforced with alumina particles and made by ?hot pressing? method. Alumina-based particles were made by sol-gel technique. The particles were characterized by the X-ray diffraction (XRD). The resulting alumina particles were modified with (3mercaptopropyl) trimethoxysilane (MPTMS), in order to obtain better mechanical properties of the composite relative to the composite with unmodified alumina particles. The aim of this work was to study the influence of composite structure and the moisture absorption on bending and the impact properties of the hybrid composite. The bending and impact tests revealed that modulus of elasticity and absorbed energy of deformation increased with modification of alumina and slightly decrease after moisture absorption.


The pure and Mg2+ doped CeO2 quantum dot were synthesized by sol-gel technique. The prepared quantum dots were characterized using X-ray diffraction pattern (XRD), Scanning electron microscope (SEM-EDX). The XRD results show cubic structure of the CeO2 quantum dots. The crystalline size (D), microstrain (ε), dislocation density (δ) and lattice parameter (α) were calculated and analyzed. SEM-EDX analysis shows the morphology and the presence of elements. The photocatalytic activity of the synthesized quantum dot was evaluated based on the photodegradation of methylene blue (MB) by UV-Vis spectrometry.


2021 ◽  
Author(s):  
Deniz ÇOBAN ÖZKAN ◽  
Ahmet Türk ◽  
Erdal Celik

Abstract The present research demonstrates the synthesis and characterization of LaMnO3 perovskite powders using the sol-gel technique for dye-sensitive solar cell applications. With this respect, transparent solutions were prepared from La and Mn based precursors, distilled water and citric acid monohydrate. Ammonium hydroxide was incorporated into the La-Mn solution in order to neutralize/precipitate at 24oC for 1 hour in the air. The solution was allowed to evaporate on a hot plate device at 90 °C in the air. The obtained solutions were dried at 90 oC for 24 hours to form a xerogel structure, dried at 200 oC for 2 hours and consequently annealed at 500 and 850 oC for 2 hours in the air. Thermal, structural, microstructural, optical and magnetic properties of the powders were characterized through differential thermal analysis-thermogravimetry (DTA-TG), Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), scanning electron microscopy (SEM), Malvern zeta sizer (PSD), UV-vis spectrometer and vibrating sample magnetometer (VSM). The obtained results indicate promise, especially the low band range, that LaMnO3 powders can be used in dye-sensitized solar cells and can positively affect performance and efficiency.


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