Preparation and characterization of new visible-light-driven BaCo0.5Nb0.5O3 photocatalyst

A new type of visible-light-driven photocatalyst BaCo0.5Nb0.5O3 was successfully synthesized via a sol-gel process in this study. After heating the precursors at 1000 degrees C, a pure perovskite phase was obtained. The particle size and crystallinity of BaCo0.5Nb0.5O3 powders markedly increased with a rise in the calcination temperature. The band gap of BaCo0.5Nb0.5O3 calculated from the UV-visible spectra was found to be less than that of titania. BaCo0.5Nb0.5O3 was demonstrated to have photocatalytic activity under visible light irradiation and this activity significantly depended on the synthesis temperature. The sol-gel derived powders were found to have better photocatalytic activity than the solid-state derived powders because of the reduced particle size and increased surface area. (C) 2007 Elsevier B.V. All rights reserved.