Titanium dioxide (Titania) has been utilized in photocatalysis since the discovery of the early 1970s. Since then, researchers have developed a variety of methods to tune the nanostructure and the composition to optimize the photocatalytic efficiency. Compared with nanoparticles or the bulk materials, nanotubular-structure titania possesses larger specific surface area and stronger adsorption capacity that results to a better photocatalytic effect. These unique chemical and physical properties allow titania nanotubes (TNT) to be widely used in sewage treatment, air purification, and sterilization areas.

Thermal sprayed cemented carbides such as WC–Co(Cr) and Cr3C2–NiCr coatings are well known and widely used for wear protection purposes. Nanocarbides in cermets have shown promising results in gaining the hardness , wear performance in abrasion, cavitation  or slurry type of wear conditions. Even friction properties have been reported to be improved by the use of nanocarbides. The driving force for reducing the carbide grain size comes from the fact that, as the carbide size becomes smaller, the binder mean free path is reduced, resulting in higher resistance to deformation and material loss. Many researchers have pursued such a hypothesis so as to improve the wear performance of HVOF WC–Co by reducing the WC grain size to the nanoscale.