Structural characterization of LaCoO3 perovskite nanoparticles synthesized by sol–gel autocombustion method

Abstract

Abstract Nanostructure perovskites such as LaMO3 (where M = transition metal such as Mn, Co, Ni, and Fe) have captured attention in materials science fields due to their promising catalytic properties. In this study, the LaCoO3 perovskite nanoparticles were synthesized by a two‐step route via the sol–gel autocombustion method. In this method, lanthanum nitrate and cobalt nitrate were used as metals sources, after dissolving in distilled water. PVP was used as a surfactant, while urea and glycine were applied as fuel. The sol was formed at the stirring stage at 60°C, and then continued to gelation through water evaporation at 90°C, to end up in the autocombustion state. The product of combustion was washed, centrifuged three times, and heat‐treated at 600°C for 2 h. Synthesized nanoparticles were characterized by scanning electron microscopy, X‐ray powder diffraction (XRD), and particle size analyzer. Characterization results show that nanoparticles were synthesized in a narrow size range, below 100 nm, with perovskite structure using sol–gel autocombustion method; these particles were spherical in shape and without visible porosity on the surface. The purity and crystalline size of nanoparticles were studied through XRD analysis indicating that variation in these parameters depends on the fuel and fuel‐to‐oxidizer ratio, as impurities decreased by increasing the fuel ratio, for both glycine and urea. In addition, using glycine is demonstrated to result in better purity as compared with urea as fuel.

Keywords

• autocombustion
• LaCoO3
• nanoparticle
• nanostructure
• perovskite
• sol–gel