Switching of the products by changing the size and shape of catalytic nanoparticles during CVD growth of MoS2 nanotubes

Abstract

Nanowires of layered materials are important because they exhibit the highest sensitivity as electrically-detecting chemical sensors. MoS₂ 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 (MoS₂ nanowires to SiO₂ nanowires) has been observed when the shapes and sizes of the FeO nanoparticles changed. MoS₂ nanowires were grown in the presence of six-horned octahedral nanoparticles, whereas SiO₂ 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 SiO₂ and MoS₂ nanowires are competing, giving rise to the observed switching.