Tube‐in‐Tube TiO₂ Nanotubes with Porous Walls: Fabrication, Formation Mechanism, and Photocatalytic Properties

Abstract

Self-organized, freestanding TiO2 nanotube arrays that exhibit tube-in-tube morphology are fabricated using a one-step anodic method. These arrays are uniform and compact. The tubes within the arrays are several micrometers long with a 200 nm outer diameter. They have a coarse lateral profile that leads to a large aspect ratio and guarantees good photocatalytic properties.