Fabrication and applications of metal-oxide nanotubes

Metal-oxide nanotubes can be used for a wide range of applications, such as selective chemical and biological sensors, dye-sensitized solar cells and photo-catalysts. The fabrication methods can be categorized into a directed method using nanotemplates (sol-gel method and atomic layer deposition) and a non-directed method (anodization). This review article describes the recent progress made in the field of oxide nanotube synthesis and applications. We begin this review with a comprehensive study on the research activities in the oxide nanotube fabrication. We then focus on pristine metal oxide applications as well as surface- modified metal oxide nanotube applications. Finally, we summarize this article with future direction in the oxide nanotube applications.