Switching of the products by changing the size and shape of catalytic nanoparticles during CVD growth of MoS2 nanotubesElectronic supplementary information (ESI) available. See DOI: 10.1039/c7ce00608j

Nanowires of layered materials are important because they exhibit the highest sensitivity as electrically-detecting chemical sensors. MoS 2 nanowires have been synthesized by a catalytic chemical vapor deposition method on silicon substrates drop-coated with FeO nanoparticles of different shapes. Switching of the products (MoS 2 nanowires to SiO 2 nanowires) has been observed when the shapes and sizes of the FeO nanoparticles changed. MoS 2 nanowires were grown in the presence of six-horned octahedral nanoparticles, whereas SiO 2 nanowires were formed in the presence of spherical nanoparticles. Their morphology, crystal structure and elemental composition have been fully investigated to elucidate the growth mechanism of the nanowires. The kinetics of the grown SiO 2 and MoS 2 nanowires are competing, giving rise to the observed switching. MoS 2 nanotubes are grown by CVD with FeO catalyst nanoparticles, which competes with the formation of SiO 2 nanowires.