Radial growth of carbon nanocoils on stainless steel wires coated with tin particles using chemical vapor deposition from acetylene

Radial growth of carbon nanocoils (R-CNCs) on stainless steel (SS) wire has been achieved using thermal chemical vapor deposition from acetylene. A solution of tin acetate in ethanol with molarities of 0.01-0.2 M was coated on SS wire and oxidized as an active catalyst in air at 600-1000 °C. It was found that SS wire oxidized at 900 °C for 30 min with a tin solution of 0.1 M exhibited the highest catalytic activity. The optimum grain size of Fe-Sn was approximately 0.49 ± 0.15 μm for R-CNCs. The R-CNCs, which were hollow in the center, had an average fiber diameter of 360 nm, a coil diameter of 960 nm and a pitch of 1140 nm. The yield, which was the ratio of the number of R-CNCs to the total carbon products, was 80%. The resistance of as-grown CNC/SS wire coated with higher-molarity solutions was lower than that of the CNC/SS wire coated with lower-molarity solutions. Growing R-CNCs on metal wire provides excellent electrical contact, good alignment, and ease of handling and manipulation.