Synthesis and photocatalytic properties of Cu2O/BiOCl semiconductor films

Cu₂O/BiOCl composite films were synthesized by a simple two-step-method: sol-gel dip-coating technique and magnetron sputtering. At first, the BiOCl thin film was prepared on indium tin oxide (ITO) substrate via a simple sol-gel dip-coating technique. Then the Cu₂O thin film was fabricated on the surface of the BiOCl thin film by magnetron sputtering. Their photocatalytic activities were evaluated by photocatalytic degradation of Rhodamine B (RhB) under UV and visible light irradiation, respectively. It was found that the photocatalytic activity of the Cu₂O/BiOCl composite films was higher than single BiOCl thin film and single Cu₂O thin film. The photocatalytic efficiency of the as-synthesized films seems to strongly depend, that is mainly due to both of the Cu₂O works as a sensitizer absorbing visible light and the Cu₂O/BiOCl hetero-junction promoting the separation rate of photo-generated electron-hole pairs. The mechanism has been discussed on the interparticle charge transfer between two semiconductors while they have the suitable relative band position.