Enhanced Photocatalytic Performance under Visible and Near-Infrared Irradiation of Cu1.8Se/Cu₃Se₂ Composite via a Phase Junction.

A novel Cu1.8Se/Cu₃Se₂ composite photocatalyst was prepared by the simple precipitation method. This composite possesses a wide photoabsorption until the range of near-infrared light, and exhibits significantly enhanced photocatalytic activity for methyl orange degradation under visible and near-infrared light irradiation compared with bare Cu1.8Se and Cu₃Se₂. The mechanism of this outstanding photocatalytic behavior can be explained by the calculated energy band positions. The efficient charge separation via a phase junction of Cu1.8Se/Cu₃Se₂ composite would make a great contribution to its much-enhanced photocatalytic efficiency.