Honeycombed TiO2 nanotube arrays with top-porous/bottom-tubular structures for enhanced photocatalytic activity

In this paper, the honeycombed top-porous/bottom-tubular TiO2 nanotube arrays (TiO2 NTs) were prepared by a facile two-step anodization method. The structural parameters of honeycombed TiO2 NTs can be well controlled by adjusting the voltages in the second-step anodization process, and the honeycombed TiO2 NTs showed much enhanced photocatalytic activity than the conventional 1-step TiO2 NTs.