Expansion of the photoresponse window of a BiVO 4 photocatalyst by doping with chromium(vi).

Doping of Cr 6+ into BiVO 4 was examined in this study. A new absorption band with a 1.84 eV energy threshold appeared with Cr-doping. The theoretical band calculation has revealed that the new absorption is ascribed to the electron transition from the valence band to acceptor levels formed by empty Cr 3d orbitals. It was confirmed that photocatalytic water oxidation in the presence of Ag + or Fe 3+ of an oxidizing reagent was induced by excitation of the new absorption although activity under band gap excitation decreased with Cr-doping. Characteristics of carrier dynamics were also investigated by transient absorption spectroscopy.