Catalysing the production of multiple arm carbon octopi nanostructures

Octopus-like carbon nanofibres with leg diameters as small as 9 nm are reported, with a high yield over large areas, using a unique photo-thermal chemical vapour deposition system. The branched nature of these nanostructures leads to geometries ideal for increasing the surface area of contacts for many electronic and electrochemical devices. The manufacture of these structures involves a combination of a polyacrylonitrile/polysiloxane film covering the surface of cupronickel catalysts, supported on silicon. Acetylene is used as the carbon feedstock. High-resolution electron microscopy revealed a relationship between the geometry of the nanoparticles and the catalytic growth process, which can be tuned to maximise geometries (and therefore the surface area) and was obtained with a catalyst size of 125 nm. The technique proposed for growing these carbon octopi nanostructures is ideal to facilitate a new in situ transfer film process to place high-density carbon structures on secondary surfaces to produce high capacitance all-carbon contacts.