Research Trends in Doping Methods on TiO₂ Nanotube Arrays Prepared by Electrochemical Anodization

Abstract

Nanotubular TiO2 prepared by electrochemical anodization has been significantly used for various applications due to high aspect ratio structures showing a high chemical stability. Morphological properties of nanotubular titanium oxide are easily tailored by adjusting types and compositions of electrolyte, pH value, applied voltage, temperature and anodization time. Since their catalytic properties can be enhanced by doping foreign elements into TiO2, metal as well as non-metal elements are doped into TiO2 nanotubes using different methods. For example, single anodization, thermal annealing, precipitation, and electrochemical deposition have been applied to simplify the doping process. In this review, anodization of Ti to produce TiO2 and doping methods will be discussed in detail.