In this paper, multiwalled carbon nanotubes (MWNTs) have been functionalized by two methods, which are a concentrated acid treatment and a noncovalent treatment by a polyelectrolyte. The structure of the carbon nanotubes after treatment has been characterized by Raman measurements. Zeta potential analysis shows that the carbon nanotubes become obviously negatively charged after these two treatments. Inorganic nanoparticles, including NiFe2O4, CdS and SnO2 are homogeneously attached onto the functionalized MWCNTs using an in situ formation method utilizing the electrical attraction between the functionalized MWCNTs and the metal ions. The composites obtained have been characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopic (EDS) analysis. These composites can be potentially useful for fabricating catalysts, photovoltaic cells, light-emitting diodes, etc..

Keywords: Carbon nanotube; Functionalization; Hybrid material