Photocatalytic Properties of Cu₂O/TiO₂ Double-Layered Composite Films Grown by Magnetron Sputtering

Based on anatase TiO₂(101) film and rutile TiO₂(200) film prepared by magnetron sputtering, Cu₂O/TiO₂(101) double-layered films and Cu₂O/TiO₂(200) double-layered films were prepared. The formation of double-layer composite films was confirmed by XRD. The surface morphologies and the section thicknesses were observed by SEM. The results of photocatalytic experiments showed that the double-layered composite films have a huge progress compared with pure TiO₂ films in the catalytic decomposition of the methylene blue solution. Among the prepared samples, the photocatalytic activity of the double-layered Cu₂O/TiO₂(101) thin films were the highest, with a catalytic efficiency of 54% and a catalytic rate of 0.367 h^‒1. There were two reasons that lead to the photocatalytic properties of composite film enhancement. First, the absorption spectrum of the composite film was wider than that of a pure TiO₂ film; second, the heterojunction could promote the transfer of interfacial charges and the separation of photogenerated electron–holes.