Decoration of Metal Nanoparticles and Metal Oxide Nanoparticles on Carbon Nanotubes

Carbon nanotubes (CNTs) have gained massive attention given their special and unique features including high surface area, suitable chemical and electrochemical stability, unique mechanical and electronic features, as well as unidimensional structure. Two groups of CNT-based hybrids that have received much attention include nanotube/metal nanoparticles and nanotube/oxide nanoparticles hybrids. There are two major methods for preparing such hybrids: (I) in situ formation of nanoparticles in the presence of nanotubes, (II) use of prefabricated nanoparticles and binding them to the nanotube surface. In the CNTs decoration, the aim is to deposit nanoparticles with adhesivity on the nanotubes surface and a suitable bonding should be established between these two materials. Meanwhile, to achieve a hybrid with improved properties, the initial nanotube features should be kept as much as possible. Three principal methods have been evaluated for CNTs decoration: (I) electrochemical deposition and electroless, (II) chemical deposition, and (III) physical deposition. In this study, the aim is to examine different methods of CNTs decoration and to present the mechanism of methods. For this purpose, different examples related to each method and the effective parameters have been evaluated and discussed. Likewise, recent advances in CNTs decoration with metal and metal oxide nanoparticles have been explored in different applications.