Solvent effect on synthesis of perovskite-type La1-xCaxCoO3 and their electrochemical properties for oxygen reactions

The object of the present investigation is to compare some physico-chemical properties of two La1-xCaxCoO3 series (0.0 less than or equal to x less than or equal to 0.6), prepared by the sol-gel route using either water or propanol as solvents. The synthesized oxide powders were characterized by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), BET, and electrical conductivity measurements. The morphology of the powders was examined using scanning electron microscopy (SEM). The results revealed that the use of propanol led systematically to the formation of homogeneous oxides with a single perovskite-structure phase, larger surface area, and higher conductivity values compared with those prepared using water. Such features, which seem to be directly related to the properties of the solvent of the starting solution, are undoubtedly favorable for a higher electrocatalytic activity of these oxides in oxygen electrode reactions. (C) 2001 Elsevier Science Ltd. All rights reserved.