Geopolymer/CeO2 as Solid Electrolyte for IT-SOFC

As a material for application in the life sciences, a new composite material, geopolymer/CeO2 (GP_CeO2), was synthesized as a potential low-cost solid electrolyte for application in solid oxide fuel cells operating in intermediate temperature (IT-SOFC). The new materials were obtained from alkali-activated metakaolin (calcined clay) in the presence of CeO2 powders (x = 10%). Besides the commercial CeO2 powder, as a source of ceria, two differently synthesized CeO2 powders also were used: CeO2 synthesized by modified glycine nitrate procedure (MGNP) and self-propagating reaction at room temperature (SPRT). The structural, morphological, and electrical properties of pure and GP_CeO2-type samples were investigated by X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR), BET, differential thermal and thermogravimetric analysis (DTA/TGA), scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), and method complex impedance (EIS). XRPD and matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) analysis confirmed the formation of solid phase CeO2. The BET, DTA/TGA, FE-SEM, and EDS results indicated that particles of CeO2 were stabile interconnected and form a continuous conductive path, which was confirmed by the EIS method. The highest conductivity of 1.86 × 10−2 Ω−1 cm−1 was obtained for the sample GP_CeO2_MGNP at 700 °C. The corresponding value of activation energy for conductivity was 0.26 eV in the temperature range 500–700 °C.

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Structural, morphological and electrical properties of multi-doped calcium phosphate materials as solid electrolytes for intermediate temperature solid oxide fuel cells

Science of Sintering ◽

10.2298/sos1801095m ◽

2018 ◽

Vol 50 (1) ◽

pp. 95-109 ◽

Cited By ~ 3

Author(s):

Miljana Mirkovic ◽

Anja Dosen ◽

Suzana Eric ◽

Marija Stojmenovic ◽

Branko Matovic ◽

...

Keyword(s):

Solid Oxide Fuel Cells ◽

Solid Electrolytes ◽

Complex Impedance ◽

Cost Effective ◽

Precipitation Method ◽

Partial Substitution ◽

Acetate Solution ◽

X Ray Diffraction ◽

X Ray ◽

Effective Synthesis

Modified solution precipitation method was used to prepare pure and doped Mg, Sr and Na hydroxyapatite type materials (CaP, CaMgP and CaSrNaP). Modification consisted of partial substitution of nitrates by acetate solution in order to achieve a more soluble and cost effective synthesis. The obtained samples were calcined at 400?C (CaP400, CaMgP400 and CaSrNaP400). All powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Calcined samples were densified at 1000?C in an air for 3 h (CaP1000, CaMgP1000 and CaSrNaP1000). Sintered samples were characterized by XRPD, FTIR, SEM, EDS and complex impedance methods. The highest conductivity was found for the multi-doped phosphate sample (CaSrNaP1000) at 700?C (1.90?10-3?-1cm-1). The corresponding activation energies of conductivity amounted to 0.31 eV in the temperature range 500-700?C.

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Promising solid electrolyte material for an IT-SOFC: crystal structure of the cerium gadolinium holmium oxide Ce0.8Gd0.1Ho0.1O1.9 between 295 and 1023 K

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229617017946 ◽

2018 ◽

Vol 74 (2) ◽

pp. 236-239 ◽

Cited By ~ 2

Author(s):

Sri Rahayu ◽

Jennifer S. Forrester ◽

Girish M. Kale ◽

Mojtaba Ghadiri

Keyword(s):

Crystal Structure ◽

Solid Oxide Fuel Cells ◽

Solid Electrolyte ◽

Sol Gel ◽

Fluorite Structure ◽

Sodium Ion ◽

X Ray Diffraction ◽

X Ray ◽

Increasing Temperature ◽

Co Doped

The crystal structure of Ce0.8Gd0.1Ho0.1O1.9 (cerium gadolinium holmium oxide) has been determined from powder X-ray diffraction data. This is a promising material for application as a solid electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Nanoparticles were prepared using a novel sodium alginate sol-gel method, where the sodium ion was exchanged with ions of interest and, after washing, the gel was calcined at 723 K in air. The crystallographic features of Gd and Ho co-doped cerium oxide were investigated around the desired operating temperatures of IT-SOFCs, i.e. 573 ≤ T ≤ 1023 K. We find that the crystal structure is a stable fluorite structure with the space group Fm\overline{3}m in the entire temperature range. In addition, the trend in lattice parameters shows that there is a monotonic increase with increasing temperature.

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In situ remediation of arsenic-rich mine tailings using slag zero valence iron

Mineralogical Magazine ◽

10.1180/mgm.2020.26 ◽

2020 ◽

Vol 84 (3) ◽

pp. 420-434

Author(s):

Tingting Yue ◽

Shu Chen ◽

Jing Liu

Keyword(s):

Photoelectron Spectroscopy ◽

Solid Phase ◽

Low Cost ◽

Selective Extraction ◽

Hunan Province ◽

Control Group ◽

X Ray Diffraction ◽

Land Occupation ◽

X Ray

AbstractArsenopyrite (FeAsS) and realgar (As4S4) are two common arsenic minerals that often cause serious environmental issues. Centralised treatment of arsenic-containing tailings can reduce land occupation and save management costs. The current work examined the remediation schemes of tailings from Hunan Province, China, where by different tailings containing arsenopyrite and realgar were blended with exogenous slag zero valence iron (ZVI). Introducing Fe-oxidising bacteria (Acidithiobacillus ferrooxidans) recreates a biologically oxidative environment. All bioleaching experiments were done over three stages, each for 7 days and the solid phase of all tests was characterised by scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and selective extraction analyses. The results showed that the mixture group reduced arsenic release by 72.9–74.7% compared with the control group. The addition of 0.2 g ZVI clearly decreased arsenic release, and the addition of 4.0 g ZVI led to the lowest arsenic release among all tests. The decrease of arsenic released from the tailings was due to the adsorption and uptake of arsenic by secondary iron-containing minerals and Fe–As(V) secondary mineralisation. The addition of large amounts of ZVI reduced the arsenic detected in the amorphous Fe precipitates. Therefore, a low cost and integrated strategy to reduce arsenic release from tailings is to mix two typical tailings and apply exogenous slag ZVI, which can apply to the in situ remediation of two kinds or more arsenic-containing tailings.

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Potential of Green Ceramics Waste for Alkali Activated Foams

Materials ◽

10.3390/ma12213563 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3563 ◽

Cited By ~ 3

Author(s):

Barbara Horvat ◽

Vilma Ducman

Keyword(s):

Low Cost ◽

Alkali Activation ◽

Activation Process ◽

Foaming Agents ◽

Insulating Material ◽

X Ray ◽

Thermal Insulating ◽

Technical Ceramics ◽

Body Residue ◽

Alkali Activated

The aim of the paper is to research the influence of foaming and stabilization agents in the alkali activation process of waste green ceramics for future low cost up-cycling into lightweight porous thermal insulating material. Green waste ceramics, which is used in the present article, is a green body residue (non-successful intermediate-product) in the synthesis of technical ceramics for fuses. This residue was alkali activated with Na-water glass and NaOH in theoretically determined ratio based on data from X-ray fluorescence (XRF) and X-ray powder diffraction (XRD) that was set to maximise mechanical properties and to avoid efflorescence. Prepared mixtures were compared to alkali activated material prepared in theoretically less favourable ratios, and tested on the strength and density. Selected mixtures were further foamed with different foaming agents, that are Na-perborate (s), H2O2 (l), and Al (s), and supported by a stabilization agent, i.e., Na-dodecyl sulphate. The goal of the presented work was to prepare alkali activated foam based on green ceramics with density below 1 kg/l and compressive strength above 1 MPa.

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Hydration Resistance of CaO Material Prepared by Ca(OH)2 Calcination with Chelating Compound

Materials ◽

10.3390/ma12142325 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2325 ◽

Cited By ~ 4

Author(s):

Jinhu Wang ◽

Yaowu Wei ◽

Nan Li ◽

Junfeng Chen

Keyword(s):

Bulk Density ◽

Grain Growth ◽

Photoelectron Spectroscopy ◽

Solid Phase ◽

Energy Dispersive Spectrometer ◽

Liquid Phase Sintering ◽

Apparent Porosity ◽

X Ray ◽

Hydration Resistance ◽

Chelating Compounds

The hydration resistance of CaO materials prepared by Ca(OH)2 calcination with chelating compounds are investigated in this paper. The crystalline phases and microstructure characteristics of sintered specimens were studied by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and energy dispersive spectrometer (SEM, EDS). The bulk density, apparent porosity, and hydration resistance of samples were also tested. The results showed that chelating compounds improved the hydration resistance of the treated CaO specimens significantly. The surface-pretreated specimens showed an increase in bulk density and a decrease in apparent porosity after heating. The surface pretreatment of the Ti chelating compound promoted the solid phase sintering and grain growth of CaO specimens, which increased the density of the heated CaO sample. The Al chelating compound promoted the liquid-phase sintering of CaO specimens, which led to the grain growth and increased density of the sample. CaO grains were bonded by the formed tricalcium aluminate (C3A) and the apparent porosity of the sample was reduced, reducing the contact area of CaO with water vapor. The Al chelating compound was more effective in improving the hydration resistance of the CaO material in the situation of this study.

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Synthesis and Microwave-Absorbing Properties of Ni-Carbon Sphere Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.552 ◽

2011 ◽

Vol 399-401 ◽

pp. 552-555 ◽

Cited By ~ 1

Author(s):

Yuan Guang Zhang ◽

Hong Yu Xia ◽

Ying Guo Zhao

Keyword(s):

Electron Microscopy ◽

Solid Phase ◽

Energy Dispersive Spectrometer ◽

Synthetic Approach ◽

Carbon Sphere ◽

X Ray Diffraction ◽

X Ray ◽

Microwave Absorbing Properties ◽

Transmission Electron ◽

Microwave Absorbing

A simple solid-phase synthetic approach has been exploited for the preparation of Ni-carbon sphere composites using Ni(CH3COO)2•4H2O as nickel source, and vitamin C (L-ascorbic acid) as reductant and carbon source at 500oC for 6 h. The products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectrometer (EDS), raman spectroscopy and microwave-absorbing measurement. The results show that the products are composed of Ni-carbon sphere particles with average diameters of 1.2 µm. Each sphere particle contains embedded Ni particles with average diameters of 83 nm. The reflection loss (RL) values of the products are lower −10 dB at 2–18 GHz, displaying broad range of microwave absorption. Their minimum RL value is about −33 dB at 4.2 GHz, which exhibit good microwave absorbing properties.

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Green synthesis and characterization of Ag1/2Al1/2TiO3 nanoceramics

Materials Science-Poland ◽

10.1515/msp-2015-0006 ◽

2015 ◽

Vol 33 (1) ◽

pp. 59-72 ◽

Cited By ~ 1

Author(s):

Sandeep Kumar ◽

Anal K. Jha ◽

K. Prasad

Keyword(s):

Low Cost ◽

Complex Impedance ◽

Dielectric Study ◽

Powder Particle Size ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Ft Ir ◽

Acid Gel ◽

Electrical Components

AbstractSingle phase silver aluminum titanate (Ag1/2Al1/2)TiO3, later called AAT, nanoceramic powder (particle size 2 to 7.5 nm) was synthesized by a low-cost, green and reproducible tartaric acid gel process. X-ray, FT-IR, energy dispersive X-ray and high resolution transmission electron microscopy analyses were performed to ascertain the formation of AAT nanoceramics. X-ray diffraction data analysis indicated the formation of monoclinic structure having the space group P2/m(10). UV-Vis study revealed the surface plasmon resonance at 296 nm. Dielectric study revealed that AAT nanoceramics could be a suitable candidate for capacitor applications and meets the specifications for “Z7R” of Class I dielectrics of Electronic Industries Association. Complex impedance analyses suggested the dielectric relaxation to be of non-Debye type. To find a correlation between the response of the real system and idealized model circuit composed of discrete electrical components, the model fittings were performed using the impedance data. Electric modulus studies supported the hopping type of conduction in AAT. The correlated barrier hopping model was employed to successfully explain the mechanism of charge transport in AAT. The ac conductivity data were used to evaluate the density of states at Fermi level and minimum hopping length of the compound.

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Mineral derived lithium solid electrolyte

MRS Advances ◽

10.1557/adv.2017.620 ◽

2017 ◽

Vol 3 (23) ◽

pp. 1301-1307 ◽

Cited By ~ 1

Author(s):

Bo Wang

Keyword(s):

Crystal Structure ◽

Solid Solution ◽

Ionic Conductivity ◽

Solid Electrolyte ◽

Room Temperature ◽

Low Cost ◽

Nasicon Structure ◽

X Ray Diffraction ◽

X Ray ◽

Order Of Magnitude

ABSTRACTLithium solid electrolyte with NASICON structure in the form of Li1+2xAlxTi2−xSixP3−xO12 solid solution has been prepared by high temperature solid state reaction using low cost kaolin as the starting material. The crystal structure of the solid solution was investigated by powder X-ray diffraction. The AC impedance measurements indicate that ionic conductivity increased by more than one order of magnitude when a small amount of Al3+ and Si4+ ions were incorporated into the LiTi2(PO4)3 crystal structure. The significant improvement on ionic conductivity can be attributed to the increased interstitial Li+ ions in the crystal structure. The highest ionic conductivity was found in Li1.2Al0.1Ti1.9Si0.1P2.9O12: 8.3 x 10-5 S·cm-1 at room temperature (21°C) and 1.5 x 10-3 S·cm-1 at 100°C.

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Structural Characteristics of Bimetallic Catalysts Supported on Nano-Ceria

Journal of Nanomaterials ◽

10.1155/2011/329757 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

J. F. Bozeman ◽

H. Huang

Keyword(s):

Solid Oxide Fuel Cells ◽

Structural Characteristics ◽

Low Cost ◽

Sol Gel ◽

Average Particle Size ◽

Fluorite Structure ◽

Average Particle ◽

X Ray Diffraction ◽

X Ray ◽

Nano Ceria

Cu-Pt bimetal catalysts supported on nanocrystalline CeO2(nano-ceria) are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.

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The Effect of Activators on the Mechanical Properties and Microstructure of Alkali-Activated Nickel Slag

Advances in Civil Engineering ◽

10.1155/2020/1764108 ◽

2020 ◽

Vol 2020 ◽

pp. 1-17

Author(s):

Liwei Xu ◽

Xuefang Wang ◽

Can Guan ◽

Wenda Wu ◽

Lingling Zhang

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Energy Dispersive Spectrometer ◽

Engineering Application ◽

X Ray ◽

Different Types ◽

Lower Porosity ◽

Infrared Spectrometer ◽

Mercury Analyzer ◽

Alkali Activated

In order to mitigate problems associated with environmental pollution, alkali-activated nickel slags (AANSs) may be used as an alternative to cementitious material. However, the understanding of their mechanical properties and microstructure is currently very limited. This paper therefore explores the influence of different types and contents of three solid alkali activators, Na2SiO3, NaOH, and Na2SiO3/Na2CO3, on the compressive strength of one-part AANS. Their microstructure, hydration components, and pore structure are analyzed by means of a scanning electron microscope, an energy-dispersive spectrometer, an X-ray diffractometer, an infrared spectrometer, and a mercury analyzer. The results show that the AANS with an Na2SiO3/Na2CO3 activator has a denser microstructure, lower porosity, and a smaller pore size when compared with the AANS with the Na2SiO3 or NaOH activators. Consequently, the compressive strength of the Na2SiO3/Na2CO3 sample reached a higher compressive strength (96 MPa) than that activated by Na2SiO3 or NaOH. This strength is optimal as well as more economical as Na2O, which increased from 0.107 mol to 0.123 mol, contributes little to compressive strength. The final part of the article discusses an optimal design for the engineering application of one-part AANS.

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