Facile Synthesis of Highly Efficient p-n Heterojunction CuO/BiFeO3 Composite Photocatalysts with Enhanced Visible-Light Photocatalytic Activity

A novel heterostructured CuO/BiFeO3 composite photocatalyst was successfully prepared through a simple combination of hydrothermal and impregnation process. CuO was uniformly deposited on the surface of BiFeO3 particles with a p-n heterojunction formed at the interface between CuO and BiFeO3. CuO/BiFeO3 heterostructured photocatalysts improved the UV/Vis spectral absorption ability, and exhibited enhanced photocatalytic activities for photodegradation of methylorange or a colorless compound (i.e., phenol) under visible light. In addition, after five recycles for the photodegradation of methylorange, CuO/BiFeO3 did not exhibit significant loss of photocatalytic activity, confirming its stability and long-time reusability. The enhanced photocatalytic activity could be mainly ascribed to the p-n heterojunction structure between CuO and BiFeO3, which could significantly facilitate the separation and transfer of photogenerated electron-hole pairs. On the basis of the calculated energy bands, the photocatalytic mechanism was also proposed.