In situ preparation of free-standing nanoporous alumina template for polybithiophene nanotube arrays with a concourse base

Vertically aligned polybithiophene nanotube arrays with a concourse base were fabricated by using a free-standing nanoporous alumina template, which was prepared in situ on conductive substrates. A well defined 20 nm gap between the nanoporous template and the substrate provided substantial space, that allows for the formation of a concourse base and improved wetting of the electrolyte on the template film. As a result, the uniformity of the nanotube arrays and the adhesion of the nanotubes to substrates were improved significantly. With the concourse base, the prepared nanotube array has an estimated density of 3 x 1010 cm-2, accounting for the occupation ratio of nearly 100% to the nanochannels in alumina templates, and the prepared polybithiophene nanotubes are capable of standing alone at an aspect ratio of 5 without any tilt