Structure and Synthesis Methods for Nanowires

Nanowires (NWs), like CNTs, are also one-dimensional and well-defined crystalline structure with a high aspect ratio. NWs have demonstrated superior electrical, optical, mechanical and thermal properties. Unlike CNTs, NWs are noncarbon based materials that can consist of metals, semiconductors, or inorganic 

Synthesis mefliods of NWs basically include both vapor phase and solution techniques. Compared to physical methods such as nanohthography and other patterning techniques, chemical methods have been more versatile and effective in the synthesis of these nanowires. The chemical synthesis includes various methods thermal evaporation, chemical vapor-phase deposition, metal-organic chemical 

Although the nanowires synthesized using the template method are usually polycrystalline, recent studies have revealed that it is possible to synfliesize single crystals of nanowires by carefully controlled conditions. For example, Neumann and co-workers have demonstrated that pulse electrodeposition could be used to selectively grow either single-crystalline copper nanowires [56]. In recent work, Cao and co-workers discovered that titanium nanowires, obtained from the electrophoretic deposition method, became single crystals once their diameters had been reduced below 15 nm [57]. 

In summary, the controlled synthesis of CNTs, CNFs, and NWs is critical in order for them to be used in practical applications. In particular, the nanostructures grown on carbon paper are ideal materials for fuel cell electrodes. In the next sections, we will focus on how to use them in fuel cells. 

3 Synthesis and Characterization of Pt Catalysts Supported on Carbon Nanotubes, Carbon Nanofibers and Metal Oxide Nanowires 

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