Electrochemical Oxidation of BaFeO2.5 to BaFeO3

BaFeO3-δ perovskite nanomaterials have been synthesized by two different methods: co-precipitation (Cop) and sol-gel (Sol) methods. Rietveld analysis of the X-Ray diffraction (XRD) shows that the samples are crystallized in rhombohedral perovskite structure with space group R3c. Scanning electron microscope (SEM) of these samples showed the agglomerations of various particles. Dynamic light scattering (DLS) showed that the average particle size of BaFeO3-Cop sample is larger than that of BaFeO3-Sol sample. The amount of oxygen deficient (δ) and the valence states of Fe ions in these samples were determined from Mössbauer spectroscopy. X-ray photoelectron spectroscopy (XPS) shows the elemental compositions and surface electronic states of these samples. The thermal, optical and magnetic properties of these samples depend on the amount of oxygen deficient (δ) and the valence states of Fe ions. Furthermore, the antibacterial and antibiofilm activity of these samples was systematically investigated. The present results suggest that BaFeO3-δ superparamagnetic perovskite can be used as antibacterial and antibiofilm agent.

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“…1b) with rhombohedral perovskite structure (space group R3c) [21]. These results are in agreement with the previous report [21]. From Fig.…”

Section: Xrd Sem and Dls Studiessupporting

confidence: 93%

“…The Rietveld analysis for the BaFeO 3 -Sol sample showed that it crystallizes in a single phase (Fig. 1b) with rhombohedral perovskite structure (space group R3c) [21]. These results are in agreement with the previous report [21].…”

Section: Xrd Sem and Dls Studiessupporting

confidence: 91%

Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

khalaf

Abdel-Khalek

Askar

et al. 2021

Preprint

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“…To understand the diffusion mechanism and the impact of the local cation environment on diffusion, it is necessary to study in-depth the oxygen jump behavior. However there are several challenges 85 in this type of study. First, it is difficult to ascribe oxygen atoms to a certain site due to their random movements at elevated temperature.…”

Section: Simulations and Data Analysismentioning

confidence: 99%

“…Additionally, electrochemical methods can be used to oxidize BFO in order to obtain a cubic phase. 19 However, the practical applications of those synthesis methods are limited because the working temperature of SOFCs or oxygen transport membranes is much higher than the conditions of synthesis. Nevertheless, doping is a simple, yet effective method to obtain the cubic phase.…”

Section: Introductionmentioning

confidence: 99%

Unraveling the effect of La A-site substitution on oxygen ion diffusion and oxygen catalysis in perovskite BaFeO₃by data-mining molecular dynamics and density functional theory

Chen

Baiyee

Ciucci

2015

Phys. Chem. Chem. Phys.

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BaFeO3 (BFO) is a promising parent material for high-temperature oxygen catalysis. The effects of La substitution on the oxygen ion diffusion and oxygen catalysis in A-site La-substituted BFO are studied by combining data-driven molecular dynamics (MD) simulations and density functional theory (DFT) calculations. The data-driven MD simulations are capable of providing atomic level information regarding oxygen jumps at different sites, bridging the resolution gap of analysis between MD and DFT. The simulations identify several effects due to the introduction of La. First, according to simple electroneutrality considerations and DFT calculations, La tends to decrease the concentration of oxygen vacancies in BFO. Second, La substitution lowers the activation energy of local oxygen migration, providing faster paths for oxygen diffusion. The MD analysis predicts a higher hopping rate through La-containing bottlenecks as well as easier oxygen jumps from the La-rich cages and lower dwell times of oxygen in those cages. DFT calculations confirm a lower migration energy through La-containing bottlenecks. Third, the electrocatalytic activity of the material decreases with La, as indicated by a lower O p-band center and higher oxygen vacancy formation energies.

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“…Depending on the preparation conditions (temperature, partial oxygen pressure, and cooling rate), a series of BaFeO 3‐ δ phases with different oxygen content can be synthesized. The known BaFeO 3‐ δ oxides with various oxygen content δ adopt the following crystal structures—for 0.07 < δ ≤ 0.15, the 12H hexagonal symmetry characterized by unit cell parameters: a = 5.691 Å and c = 27.974 Å; 34,35 for 0.2 < δ ≤ 0.35, the 6H hexagonal symmetry with the lattice parameters: a = 5.685 Å and c = 13.96 Å; 34,36,37 for 0.44 < δ ≤ 0.46, an orthorhombic structure; 36 and for δ = 0.5, a monoclinic structure related to an oxygen vacancy ordered phase 34,36,38 . According to ref 39 .…”

Section: Introductionmentioning

confidence: 99%

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

et al. 2022

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The phase equilibria in the ½Nd 2 O 3 -BaO-½Fe 2 O 3 system were systematically studied at 1373 K in air and presented in the form of a phase diagram. By X-ray diffraction (XRD) analysis of quenched samples, the homogeneity ranges and crystal structure were determined for the following intermediate oxides: Nd 1-x Ba x FeO 3-δ with 0.0 ≤ x ≤ 0.05 (space group (SG) Pnma) and with 0.6 ≤ x ≤ 0.7 (SG Pm-3m), Ba 6+y Nd 2-y Fe 4 O 15-δ with 0.0 ≤ y ≤ 0.4 (SG P6 3 mc), and Ba 1.1 Nd 1.9 Fe 2 O 7-δ (SG P4 2 /mnm). The structural parameters of single-phase oxides were refined by the Rietveld method. The changes in oxygen content for Nd 1-x Ba x FeO 3-δ (0.6 ≤ x ≤ 0.7), Ba 6 Nd 2 Fe 4 O 15-δ , and Ba 1.1 Nd 1.9 Fe 2 O 7-δ versus temperature in air were determined by thermogravimetric analysis. Gradual substitution of neodymium by barium in the Nd 1-x Ba x FeO 3-δ (0.6 ≤ x ≤ 0.7) oxides leads to a decrease of oxygen content. Partial ordering via formation of separate domains with a p × a p × 5a p superstructure in Nd 0.4 Ba 0.6 FeO 3-δ , which cannot be detected by XRD, noticeably influence its thermal expansion and electrical conductivity.

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Electrochemical Oxidation of BaFeO2.5 to BaFeO3

Cited by 13 publications

References 23 publications

Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

Unraveling the effect of La A-site substitution on oxygen ion diffusion and oxygen catalysis in perovskite BaFeO₃by data-mining molecular dynamics and density functional theory

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides

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Electrochemical Oxidation of BaFeO2.5 to BaFeO3

Cited by 13 publications

References 23 publications

Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

Effect of Synthesis Method on Antibacterial and Antibiofilm Activity Properties of BaFeO3-δ Perovskite Nanomaterials

Unraveling the effect of La A-site substitution on oxygen ion diffusion and oxygen catalysis in perovskite BaFeO3by data-mining molecular dynamics and density functional theory

Phase equilibria in the Nd2O3–BaO–Fe2O3 system: Crystal structure, oxygen content, and properties of intermediate oxides

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Unraveling the effect of La A-site substitution on oxygen ion diffusion and oxygen catalysis in perovskite BaFeO₃by data-mining molecular dynamics and density functional theory

Phase equilibria in the Nd₂O₃–BaO–Fe₂O₃ system: Crystal structure, oxygen content, and properties of intermediate oxides