A novel solid-liquid two-phase precipitation (SLTPP) method, utilising a solidified (vialiquid N 2)m-xylene solution of C 60with liquid isopropanol (IPA) as a counter-solvent, is proposed for the synthesis of fullerene (C 60) nanowires. The resulting C 60nanowires were observed to possess high crystallinity and a length-to-diameter ratio of up to several thousands with a diameter as small as ∼85 nm. We further systematically investigated the effects of the C 60concentration (1-5.2 mg ml −1) and solvent-counter-solvent ratio (1 : 6-2 : 1) to optimise the growth conditions for high-quality, size-controlled C 60nanowires. A comparative study on the widely-used liquid-liquid interfacial precipitation (LLIP) method showed that the proposed SLTPP method led to a much narrower diameter distribution (414.20 ± 92.10 nmvs.3237.20 ± 1790.30 nm for LLIP) across the studied range of the C 60concentrations and solvent-counter-solvent ratios, and is therefore considered to be a more stable and reliable synthesis route. We propose that the gradual melting of them-xylene C 60solid-phase leads to slower diffusion of the solvent-counter-solvent medium, providing a much more stable interface for high-quality crystal growth.
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© The Royal Society of Chemistry 2021.