Photocatalytic H2 or O2 evolution over A-site deficient perovskite-type compounds La1/3MO3 (M=Nb, Ta) from aqueous solutions

Abstract

Two compounds La 1/3 MO3 (M = Nb, Ta) with A-site deficient perovskite-type structure were synthesized by the solid state reaction method. The photocatalytic properties of these compounds were characterized by H2 evolution with Pt cocatalyst from CH3 OH/H2 O solution and by O2 evolution from AgNO3 aqueous solution under UV light irradiation. The results showed that the average rate of H2 evolution was about 61.07 μmol h -1 for La 1/3 NbO3 and 95.79 μmol h -1 for La 1/3 TaO3 after 24 hours of reaction time, while the initial rate of O2 evolution was 26.31 μmol h -1 for La 1/3 NbO3 and 16.21 μmol h -1 for La 1/3 TaO3, respectively. H2 evolution was also observed over La 1/3 MO3 (M = Nb, Ta) with NiO cocatalyst from pure water under UV light irradiation.