Sol-gel synthesis and characterization of the photocatalyst BaCo1/3Nb2/3O3

The photocatalyst BaCo1/3Nb2/3O3 has been synthesized at 750◦C by using a sol-gel process, and the surface area is 19.70 m2/g. While the surface area of the powder synthesized by using a solid state reaction process is 2.2 m2/g. It was characterized by X-ray diffraction, scanning electron microscopy(SEM), UV-vis diffuse reflectance spectroscopy, Raman scattering spectroscopy and the measurement of the photocatalytic activity in evolving H2 from CH3OH/H2O solution with the Pt co-catalyst under visible light irradiation. From the SEM image, BaCo1/3Nb2/3O3 powder calcined at 750◦C is dispersive, and the average particle size is about 30 nm. Raman scattering spectrum at room temperature shows that, due to the different ionic radius of the Co2+ and Nb5+ ions, BaCo1/3Nb2/3O3 may has a distorted perovskite structure. Under visible light irradiation (λ > 420 nm), the formation rate of H2 evolution from CH3OH/H2O solution with the 0.5 wt% Pt co-catalyst is about 18.1 μmol/h·gcat. for the photocatalyst BaCo1/3Nb2/3O3, much higher than that of BaCo1/3Nb2/3O3 powder synthesized by the solid state reaction process. C 2006 Springer Science + Business Media, Inc.