One-step fabrication of N-doped TiO2 inverse opal films with visible light photocatalytic activity

N-doped TiO2 inverse opal films were fabricated by a novel method through one-step coassembly of polymer colloidal spheres and titania precursor. This coassembly approach removed the need of preassembled colloidal crystal for precursor solution infiltration and respective chemicals for titania formation and nitrogen doping. Less crack films with well ordered inverse opal structure could be produced by adding appropriate amount of TiBALDH (titanium(IV)-bis-lactato-bis-ammonium dihydroxide) into the precursor solution. The films prepared at the optimized condition showed enhanced visible light photocatalytic activity, which could be attributed to both the N doping effect and their unique inverse opal structure.