High-throughput screening for carbon nanotube production Original Research Article

High-throughput screening has been used to optimise the catalyst composition for the growth of carbon nanotubes. Microarrays of candidate catalysts were formed by printing metal salt solutions onto quartz substrates. Each solution formed a spot approximately 250 μm in diameter, with a density of 384 different spots per square inch. The solutions consisted of three components: a catalyst precursor, a substrate precursor (TEOS) and a micelle agent (P85). The printed substrates were calcined and then reacted in methane and hydrogen. The reacted substrates were studied using Raman spectroscopy and electron microscopy. The effect of varying the relative amounts of the three components was investigated. Analysis showed that bamboo nanotubes were grown when the metal to silicon ratio was high and small diameter nanotubes, including some single-walled tubes, were grown when the ratio was low.