Nanocrystalline LaMO3 (M = Al, Fe, Co, Gd) perovskites were synthesized by the co-precipitation method using metal nitrate and carbonate salts as starting materials. The products were characterized with X-ray diffractometer (XRD), energydispersive X-ray spectrometer (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BrunauerEmmett-Teller (BET) specific surface area measurement, and UV-vis diffuse reflectance spectroscopy (DRS). The XRD patterns confirmed the formation of the perovskite phase. The SEM micrographs indicated that perovskite samples were nanosized particles with morphology containing porosity due to inter-particle voids. The measured pHpzc of LaAlO3, LaCoO3, LaFeO3, and LaGdO3 in this work were 8.6, 9.2, 9.0, and 8.1, respectively. From the DRS spectra, the band gap energies of LaAlO3, LaCoO3, LaFeO3, and LaGdO3 were calculated as 2.60, 1.50, 2.00, and 2.90 eV, respectively. The preparation of LaMO3 (M = Al, Fe, Co, Gd) perovskites in this work have several advantages such as simplicity, low cost, and no waste compared with other methods.
