The perovskite LaFeO3 synthesized by sol-gel method was characterized physically and electrochemically and applied for the oxygen production under visible light. The thermal analysis (TG-ATD/DSC), X-ray diffraction (XRD), BET surface area, attenuated total reflection, scanning electron microscopy (SEM) analysis, laser granulometry, and electrical conductivity were used for its characterization. The XRD pattern indicates that LaFeO3 is formed at 850 °C and the BET results gave a specific surface area of ~7 m2g−1. The analysis by laser granulometry confirmed the agglomerated nature observed in the SEM micrographs and attributed to the fine powder obtained by sol-gel. The oxide exhibits a brown yellowish color with a forbidden band of 2.15 eV, determined from the diffuse reflectance data. The electrical properties indicate n-type semiconductor with activation energy of 0.20 eV. LaFeO3 has a chemical stability in the pH range (5–14) with an exchange current of 35 μA cm−2 at pH 12.8. The Mott–Schottky measurement (C−2–E) corroborates the n-type behavior with a flat band potential of 0.62 VSCE and a density of 5.1 × 1018 cm−3. The perovskite LaFeO3 was used for the oxygen production upon visible light irradiation and the good performance occurred with an evolution rate of 0.094 cm3 h−1 (mg catalyst)–1 in NaOH solution (0.1 M).
