Metal sulfide coated multiwalled carbon nanotubes synthesized by an in situ method andtheir optical limiting properties

Abstract

A metal sulfide such as ZnS, CdS,Ag2S or PbS was coated on the sidewall of multiwalled carbon nanotubes (MWCNTs) by an insitu wet chemical synthesis approach via noncovalent functionalization of MWCNTs with apolyelectrolyte (polyethylenimine or poly(diallyldimethylammonium chloride)) withoutcausing significant electronic and structural modification of the carbon nanotubes.Extensive characterizations of the fabricated nanocomposites have been performed usingx-ray diffraction, transmission electron microscopy (TEM), high resolution TEM, energydispersive x-ray spectroscopy, selected area electron diffraction, thermal gravimetricanalysis, Fourier transform IR spectra, UV–vis spectra and x-ray photoelectronspectroscopy. The coating layers were composed of metal sulfide nanoparticleswith a mean size of less than 10 nm. The optical limiting property measurementsfor some metal sulfide coated MWCNTs were carried out by the open-aperturez-scan technique. The results demonstrate that the samples suspended in water showedoptical limiting behavior better than that of purified MWCNTs.