A simple and efficient preparation of LaFeO3 nanopowders by glycine–nitrate process: Effect of glycine concentration

LaFeO3 perovskites have been prepared by the glycine–nitrate process (GNP) at various glycine-to-nitrate molar ratios. The perovskites have been systematically characterized by X-ray diffraction, BET surface area, scanning electron microscopy, transmission electron microscopy and temperature-programmed reduction to study the effect of glycine concentration on various properties of LaFeO3. The X-ray diffraction patterns of the as-prepared and calcined samples show the formation of orthorhombic phase without any impurities. The BET specific surface areas of various perovskites increased with an increase in glycine-to-nitrate ratio (GNR) of 2.0 but were nearly constant at higher ratios. The scanning electron microscopy indicates that the prepared material is flake-like at GNRs ≤1.5 and exists as agglomerated particles at GNRs ≥2.0. The particle size of the as-prepared samples was in the range of 30–130 nm depending on the GNR and the calcined samples exhibited particle size in the range of 60–160 nm. The samples that were prepared at GNR < 1.5 did not show any peaks in temperature-programmed reduction, but the samples prepared at a GNR of 2.0 and above showed the reduction of Fen+.