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 spinel-type crystal structure were studied. It was found that H2 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 H2 evolution under visible light irradiation showed a maximum activity for λ>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.