Enhanced H2 Production of TiO2/ZnO Nanowires Co-Using Solar and Mechanical Energy through Piezo-Photocatalytic Effect

TiO 2 /ZnO nanowire arrays on stainless steel mesh for piezo-photocatalytic H 2 production are synthesized via a two-step hydrothermal route. The photocatalytic H 2 production efficiency under solar illumination can be enhanced by introducing mechanical vibration energy. As coutilizing the solar and mechanical energy (ultrasonic irradiation), the nanowires show high H 2 production. The nanowire arrays also show excellent recyclability and stability. Additionally, this mesh-based structure can be retrieved easily from aqueous solution, which can meet the practical application demand. The working mechanism can be attributed to the piezo-photocatalytic effect, in which the piezoelectric field of bent ZnO nanowires and the built-in electric field of TiO 2 /ZnO heterostructures can efficiently separate the photogenerated electrons and holes for effectively producing H 2 . Present results provide a new strategy for developing photocatalytic H 2 production techniques.