Solvent-deficient synthesis of nanocrystalline Ba0.5Sr0.5Co0.8Fe0.2O3-δ powder

Abstract

Nanocrystalline Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ powders were prepared by a cost-effective solvent-deficient method using metal nitrates and ammonium bicarbonate as precursors. X-ray diffraction (XRD), specific surface determination (BET), thermal analyses (TG-DTA-DSC), dynamic light scattering (DLS) and scanning electron microscopy (SEM) were used to examine the effects of the calcination temperature on the Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) formation. XRD analysis showed that a cubic Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ was obtained after heating for 1 h at 1000°C. BSCF nanocrystals with a diameter of about 25 nm were obtained. On the other hand, the sample mass was stabilized at 915°C as recorded by thermogravimetric analysis (TG), indicating a formation of the complex BSCF oxide already at this temperature. The phase transformations during the synthesis of BSCF oxide are defined and confirmed with the note on the instability of the cubic phase. Using the four-point DC measurements between −73°C and 127°C, the band gap of 0.84 eV was determined. The solvent-deficient method used in this study to synthesize Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ showed distinct advantages in comparison with other synthesis techniques considering simplicity, rapid synthesis, and quality of the produced nanocrystals.

Oxygen Evolution Reaction in Ba0.5Sr0.5Co0.8Fe0.2O3-δ Aided by Intrinsic Co/Fe Spinel-Like Surface

“…That is, the Co/Fe-rich surface is maintained after oxidative potentials are applied. Previous studies showed that the A-site cation leaching process at BSCF surface resulted from OER during cycling or holding potential. ,, Our local probing suggests that the Co/Fe-rich spinel structure is formed prior to the OER onset or during synthesis, as indicated previously. , …”

“…11,13,14 Our local probing suggests that the Co/Fe-rich spinel structure is formed prior to the OER onset or during synthesis, as indicated previously. 37,38 3.2.2. Morphological Evolution after CV.…”

A Review of Recent Development of the Solvent-Deficient Method

“…The in-depth analysis of the SD method is performed following CeO 2 synthesis [28]. The reaction mechanism and kinetics of CeO 2 synthesis using the SDM are found to be marked by the four observed stages.…”

MECHANOCHEMICALLY INDUCED SYNTHESIS OF La2O3

“…The solventdeficient method does not require complicated apparatus or setups. After the first report by Smith et al [10], this method was optimized and applied for the preparation of binary oxides such as Al2O3 [11], and CeO2 [12], and even more complex ones, such as Ba0.5Sr0.5Co0.8Fe0.2O3 [13].…”