Microstructured arrays of tio₂ nanotubes for improved photo-electrocatalysis and mechanical stabili

The preparation of micropatterned TiO₂ nanotubes (NTs) with tunable morphologies by combining laser micromachining technology and an anodization method is reported. The micropatterned structure can be easily designed and fabricated by laser micromachining a titanium substrate, further anodization of which gives nanotube arrays perpendicularly oriented to the titanium surface. The patterned TiO₂ NTs show dramatically improved photocurrent and photocatalytic performances because of their enhanced surface area and light-harvesting capability. The photocurrent density and incident-photon-to-current efficiency at the peak absorption increases by 48 and 39%, respectively, compared to a TiO₂ NT array without a patterned structure. It was also found that micropatterning dramatically improves the mechanical stability of the TiO₂ NTs on the substrate, which otherwise were liable to peel off from the substrate surface. The strategy will reasonably expand the application of TiO₂ NTs in a variety of fields that require enhanced photo-electrocatalysis and mechanical stability.