Assembly of TiO -on-Cu O Nanocubes with Narrow-Band Cu O-Induced Visible-Light-Enhanced Photocatalytic Activity.

Newly designed TiO -on-Cu O nanocubes have been constructed as visible-light-driven photocatalysts with high efficiency by means of a facile self-assembly approach at room temperature. In the resultant TiO -on-Cu O nanocubes, the TiO nanoparticles with a diameter of 6-8 nm show a well-monodispersed distribution of the 200-300 nm-sized Cu O single-crystal nanocubes, which can form sub-monolayer, monolayer, and multilayer coverage through controlling the ratio of the two phases. In particular, the coupling of the wide-bandgap semiconductor TiO with narrow-bandgap Cu O can lead to the markedly enhanced high visible-light photocatalytic activity in the TiO -on-Cu O nanocomposite systems toward the photodegradation of rhodamine B, which is induced by the bandgap-adjusting effect. This promising self-assembly route can be extended to the preparation of other nanocomposite materials.