Transparent TiO2 nanotube array photoelectrodes prepared via two-step anodization

Abstract Two-step anodization of transparent TiO 2 nanotube arrays has been demonstrated with aid of a Nb-doped TiO 2 buffer layer deposited between the Ti layer and TCO substrate. Enhanced physical adhesion and electrochemical stability provided by the buffer layer has been found to be important for successful implementation of the two-step anodization process. With the proposed approach, the morphology and thickness of NT arrays could be controlled very precisely, which in turn, influenced their optical and photoelectrochemical properties.