Ni–Mo and Co–Mo alloy nanoparticles for catalytic chemical vapor deposition synthesis of carbon nanotubes

Abstract

Here, we show for the first time a catalytic chemical vapor deposition (CCVD) synthesis of carbon nanotubes (CNTs) using polyoxomolybdate clusters Mo12O28(μ2-OH)12{Ni(H2O)3}4 and Mo12O28(μ2-OH)12{Co(H2O)3}4 as a source of catalyst nanoparticles. X-ray diffraction analyses indicated that the products of thermal decomposition of the clusters contain NiMoO4 and CoMoO4 phases, which are converted into Ni–Mo and Co–Mo alloys at 900°C in hydrogen environment. High-resolution transmission electron microscopy in combination with energy-dispersive X-ray spectroscopy confirmed the CNT growth from bimetallic nanoparticles. Synergism between two metals in an alloy resulted in large-scale production of non-bundled few-walled CNTs with narrow diameter distribution and high quality.