Synthesis, Structure, and Electrophysical and Electrochemical Properties of Novel Composite La₀.₉MnO₃–LaFeO₃

Synthesis, Structure, and Electrophysical and Electrochemical Properties of Novel Composite La₀.₉MnO₃–LaFeO₃

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  • Journal: Molecules, 2025, 30(1), 132 — MDPI

    DOI: https://doi.org/10.3390/molecules30010132

    Cite this: Mataev, M.; Sarsenbaeva, Z.; Keskin, B.; Nurbekova, M.; Meldeshov, A.; Tursyn, Z.; Seitbekova, K. Synthesis, Structure, and Electrophysical and Electrochemical Properties of Novel Composite La₀.₉MnO₃–LaFeO₃. Molecules 2025, 30, 132.

    Publication Date: 31 December 2024 (Online); 2025 (Volume 30, Issue 1)

    Article Type: Research Article | Open Access   sarsenbayeva.zamira@qyzpu.edu.kz

ABSTRACT :

This study investigates the synthesis, structural characteristics, electrical properties, and electrocatalytic performance of a novel La₀.₉MnO₃–LaFeO₃ perovskite-based nanocomposite.

The material was synthesized using the sol–gel Pechini method. X-ray diffraction analysis confirmed the formation of a crystalline, biphasic structure containing hexagonal La₀.₉MnO₃ and cubic LaFeO₃ phases.

Field-emission scanning electron microscopy (FESEM) and elemental analysis revealed the microstructural characteristics of the composite, with an average particle size of approximately 186.9 nm.

The electrical characterization demonstrated temperature-dependent conductivity and semiconducting behavior across several temperature intervals.

The electrocatalytic properties were investigated for the hydrogen evolution reaction (HER) in an acidic medium using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS).

The findings highlight the potential of La₀.₉MnO₃–LaFeO₃ as a precious-metal-free oxide material for further investigation in electrochemical hydrogen production.

Research Highlights

Biphasic Perovskite Structure: Successful synthesis of a La₀.₉MnO₃–LaFeO₃ composite with distinct crystallographic phases.

Microstructural Characterization: XRD, FTIR, FESEM, and EDS analyses provided insights into crystalline structure, surface morphology, and composition.

Electrophysical Properties: Temperature-dependent dielectric and conductivity behavior was evaluated.

Hydrogen Evolution Reaction: The composite was investigated as an electrocatalyst for HER in acidic media through LSV and EIS measurements.

SUBJECT :

Perovskite Oxides, La₀.₉MnO₃–LaFeO₃, Pechini Method, Electrophysical Properties, Electrocatalysis, Hydrogen Evolution Reaction, Hydrogen Energy

Selected Figures: 

Figure 1. Steps of preparation of La0.9MnO3-LaFeO3 particles by Pechini-type sol–gel method.
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Figure 2. XRD of the La0.9MnO3-LaFeO3.
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Table 1. Results of quantitative analysis of the crystal lattice.
N Name of Compound Types of Syngony a, Å b, Å c, Å Vc., (Å3) Z D (Crystal Size, nm) Space Group Density (ρx-Ray, g/cm3)
1 La0.9MnO3 hexagonal 5.52 5.52 13.37 354.10 6 55.29 R-3c (161) 6.40
2 LaFeO3 cubic 3.89 3.89 3.89 58.99 1 54.96 Pm-3m (211) 6.76
Figure 3. FT-IR spectra for La0.9MnO3-LaFeO3.
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Figure 4. Particle size distribution histograms and FESEM micrographs of manganite-ferrite sample. (a) FESEM micrograph; (b) EDS spectrum; (c) Particle size distribution; (d) Particle size.
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Figure 5. Dependence of dielectric permittivity (a) and electrical resistivity (b) of La0.9MnO3-LaFeO3 on temperature and frequency equal to 1 kHz.
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Figure 6. LSV curves for the nanocomposite La0.9MnO3-LaFeO3.
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Figure 7. Nyquist plot (a) and electrical equivalent circuits (Rct) (b) for La0.9MnO3-LaFeO3.
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License: Creative Commons Attribution 4.0 International (CC BY 4.0)

Source: Mataev et al., Molecules 2025, 30(1), 132. DOI: 10.3390/molecules30010132.