A new spinel-type photocatalyst BaCr2O4 for H2 evolution under UV and visible light irradiation

The photophysical and photocatalytic properties of BaCr2O4 synthesized with normal spinet-type crystal structure, were studied. It was found that H-2 could be photocatalytically evolved from the aqueous CH3OH solution suspended with Pt(0.2 wt%)/BaCr2O4 powder under irradiation of both ultraviolet (UV) and visible lights. The wavelength dependence of H-2 evolution under visible light irradiation showed a maximum activity for lambda > 540 nm. A possible electronic band structure and corresponding photoexcitation modes of BaCr2O4 under irradiation of UV and visible lights were proposed in regard to the complicated photophysical and photocatalytic properties. (C) 2003 Elsevier Science B.V. All rights reserved.