Blue TiO2 nanotube array as an oxidant generating novel anode material fabricated by simple cathodic polarization

Abstract

cally generated oxidants in industrial electrochemistry. For the last five decades, these needs have beenmostly achieved by the introduction of two well-known anode materials, the dimensional stable anode(DSA®) and boron-doped diamond (BDD) electrodes. Nevertheless, the high cost and complicated pro-cess in fabricating these electrodes remains as a big obstacle for further development. Here, we reporta novel anode material for the production of oxidants, the dark blue colored TiO2nanotube array (NTA)(denoted as Blue TiO2NTA) which has never been successfully achieved with titania-based materials. Thistitania-based electrocatalyst with irreversible electrochromism and high conductivity was successfullyfabricated with simple cathodic polarization of anatase TiO2NTA and exhibits the excellent electro-catalytic activity in generating chlorine (Cl2) and hydroxyl radical (•OH) which is comparable to thecommercial DSA®and BDD electrodes, respectively. Thus, this Blue TiO2NTA is suggested as a potentialcost effective anodic material in industrial electrochemistry. In addition, even in other metal oxides otherthan titania, the cathodic polarization (accompanied with irreversible electrochromism) method may beapplied to explore a new route for low-cost and novel anodic materials.