Active Area of Anodic TiO₂ Nanotube Arrays in Photo and Electrochemical Energy Storage Devices

The anodic TiO2 nanotube (TNT) has been promising as both electrocatalysts in electro-energy synthesis and storage devices, photoelectrocatalysts solar energy conversion devices. active area of the (photo)electrocatalyst materials must be clarified because current density can normalized to an electrochemically surface area. Herein, it is discussed whether TNT electrodes photo- electrochemicial devices reported clearness. In literature, sizes titanium (Ti) metal substrate, TNT, electrode have misunderstood different applications. Clarifying three sizes, Ti array, area, with respect substrate shapes device applications important academic research commercialization due scale-up size effect.