Direct Growth of ZnO Nanocrystals onto the Surface of Porous TiO ₂ Nanotube Arrays for Highly Efficient and Recyclable Photocatalysts

ZnO nanocrystal-coated, vertically oriented, porous TiO2 nanotube arrays (see image) are used as efficient and low-cost photocatalysts. The exposed surface area and contact area are maximized to achieve high-efficiency photocatalytic decomposition via a heterojunction effect. The configuration of vertically aligned nanotube arrays also allows the diffusion of reactants through multiple pathways to enhance light harvest.