Controlled synthesis of carbon nanocoils on monolayered silica spheres

Carbon nanocoils (CNCs) have been synthesized on monolayered silica spheres by chemical vapor deposition using Sn/Fe binary catalyst films. The average coil diameter of the CNCs can be regulated by adjusting the diameter of the silica sphere. In addition, the thickness of byproduct layer is reduced effectively by using the monolyered silica spheres, leading to an improvement in the yield of the CNCs. By patterning the Sn/Fe catalyst film using the monolayered silica spheres as mask, the average coil diameter of CNCs can be further reduced. Our results provide important guidelines for the controlled synthesis of CNCs with controllable coil diameters by adjusting the diameter of silica spheres.