We directly transformed anodized tungsten oxide film (WO3·2H2O)
into bismuth tungstate (Bi2WO6) by substituting the intercalated water molecules with
[Bi2O2]2+ in a hydrothermal treatment. The resultant Bi2WO6 was readily used as an
electrode to produce anodic photocurrent in H2 evolution on the Pt counter electrode
observed under visible light irradiation.