Journal: Ionics

Abbreviation

Ionics

Publisher

Springer

Journal Volumes

ISSN

1862-0760
0947-7047

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Filters

2018 - 201912020 - 20252
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Publications 1 - 3 of 3
  • Effect of sintering temperature and Sr/Ti ratio on the nature of Mn-ion speciation within SrTiO₃-based compounds
    Item type: Journal Article
    Łącz, Agnieszka; Gwóźdź, Paulina; Mielniczuk, Monika; et al. (2025)
    Ionics
    Manganese-doped (Mn/Ti = 0.02/0.98) SrTiO3-based materials with various Sr/Ti mole ratios (1.02, 1.00, 0.97 and 0.92) were obtained by the citrate precursor method. The materials were characterised in terms of microstructure (SEM), structure (XRD, XANES), electrical properties (DC method) and reducibility (TPR). With the introduction of 2 mol.% Mn, the cubic structure of SrTiO3 is preserved, but significantly limits (from Sr/Ti >= 0.8 to Sr/Ti > 0.92) the possibilities of deviations from stoichiometry at 1200 degrees C. The narrowing of the stability limit of the perovskite structure to Sr/Ti > 0.97 with an increase in temperature to 1400 degrees C and segregation of Ti-Mn-enrich species are shown. The location and the oxidation states of Mn in both (Sr and Ti) sublattices depend on the assumed Sr/Ti ratio and sintering temperature. Regardless of the Sr/Ti ratio, Mn-doped SrTiO3 exhibits very low electrical conductivity with an ionic conductivity mechanism.
  • Incorporation of MnO2 nanoparticles into MOF-5 for efficient oxygen evolution reaction
    Item type: Journal Article
    Fiaz, Muhammad; Kashif, Muhammad; Shah, Jafar Hussain; et al. (2021)
    Ionics
    A composite MnO2@MOF-5 is prepared by in situ incorporation of pre-synthesized MnO2 nanoparticles into metal organic framework, MOF-5, during synthesis. The product is characterized by powder X-ray diffraction analysis, Raman spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and elemental mapping, which support the formation of proposed composite materials. The oxygen evolution reaction activity of MnO2@MOF-5 composite is evaluated by cyclic voltammetry, linear sweep voltammetry, and chronoamperometric measurement under visible light. It is found that MnO2@MOF-5/NF has better durability and ability to produce a current density of 10 mAcm−2 at only 324 mV overpotential with lower 71 mVdec−1 Tafel slope as compared to some of previously reported Mn-based catalysts for oxygen evolution reaction (OER). The stability of these electrodes is evaluated by chronoamperometric studies for 6000 s in the presence of visible light, and they showed constant current density. Furthermore, the stability studied by continuous CV sweeps in 1.0 M NaOH at a scan rate of 100 mVs−1 shows that these materials are stable up to 100 cycles, which confirms the stability and durability of the electrodes.
  • High frequency impedance spectroscopy study on Gd-doped CeO2 thin films
    Item type: Journal Article
    Venckutė V.; Kazlauskas, Saulius; Kazakevičius, E.; et al. (2018)
    Ionics
Publications 1 - 3 of 3