Significantly enhanced piezo-photocatalytic properties of recyclable nanocomposite films by growing ZnO nanorods on inverse opal structured TiO2 framework

The construction of recyclable films with unique morphology and piezoelectric-enhanced photocatalytic performance is of great significance for wastewater purification. Here, inverse opal structured ZnO@TiO 2 nanocomposite film were prepared by template method and chemical water bath method. The piezo-photocatalytic properties of the obtained ZnO@TiO 2 nanocomposite films were evaluated by the degradation of organic dyes. The results showed that the piezo-photocatalytic constant rate of the ZnO@TiO 2 nanocomposite films under the synergistic action of ultrasound and ultraviolet light reached 52.3×10 −3 min −1 , much higher than those of the pure inverse opal TiO 2 framework under same condition (6.6×10 −3 min −1 ) and the ZnO@TiO 2 nanocomposite films under only ultraviolet light (10.1×10 −3 min −1 ) or only ultrasound (2.0×10 −3 min −1 ). It is believed that the inverse opal structured TiO 2 framework not only provides an open space for ZnO nanorods growth, but also initiates redox reaction for dye degradation through generation and transfer of photo-generated carriers under ultraviolet irradiation. Meanwhile, the ZnO nanorods can efficiently promote carrier separation by piezoelectric polarization electric field and interface contact induced band tilting with TiO 2 , thus significantly improving the piezo-photocatalytic activity. This work provides a novel route for reasonable design of recyclable and efficient piezo-photocatalytic films.