Synthesis and characterization of TiO2/ZrO2 coaxial core-shell composite nanotubes for photocatalytic applications

In this paper, TiO2/ZrO2 coaxial core-shell composite nanotubes were synthesized with the anodic aluminum oxide (AAO) template by a new “two-step method”: Zr(NO3)4 sol was first deposited on the nanochannels of the AAO template to form a layer of ZrO2 nanotubes, and the TiO2/ZrO2 composite nanotubes were obtained after TiF4 sol was covered on the ZrO2 precursor. The process was suitable to produce large size and well-ordered nanotube arrays. The photocatalytic activities of the samples in AAO template were evaluated by the degradation of a model dye, methyl orange (MO). Compared with TiO2 nanotubes and ZrO2 nanotubes, the TiO2/ZrO2 composite nanotubes exhibited the better photocatalytic activity. Findings from this study suggested that TiO2 nanotube arrays with enhanced photocatalytic activity could be obtained, which opened a new pathway to construct nanostructured TiO2-based composite materials for photocatalytic applications.