The synthesis of Bi 2WO 6 inverse opal photonic crystals is performed via a facile and economical method. Bi 2WO 6 inverse opals exhibit much higher photocatalytic activities for the degradation of methylene blue and salicylicic acid under visible light illumination as compared with a reference nanofilm. The photon-to-hydrogen conversion efficiencies of photoelectrochemical water splitting exhibit an almost threefold increase due to the inverse-opal structure.