Dusty plasma synthesis of nanostructured Zn/ZnO–carbon nanotube composites by aerosol flow condensation

Abstract

A new, dusty plasma process for depositing nanoparticles generated by aerosol flow condensation and treated using a 13.56 MHz capacitively-coupled non-thermal glow discharge is described. The use of organometallic compounds as nanoparticle precursors is avoided, thereby allowing for a processing plasma free of contaminating degradation products. Nanostructured composites of zinc and zinc oxide were deposited on carbon nanotubes with complete coverage, and the influences of the argon quench and sheath gas flow rates, and the presence of 0.5 vol.% ethane in the processing plasma on the synthesized composites was investigated by electron microscopy and X-ray diffraction (XRD). In the absence of plasma, ∼1 μm Zn microparticles composed of agglomerated nanoparticles were formed on the carbon nanotube surface. Plasma processing produced coatings of nanoparticles with lognormal size distributions and median diameters of ∼5 nm. At maximum argon flow rates, the distribution was monodisperse, whereas lower flow rates produced bimodal size distributions with the second mode having median values of ∼70 nm.