Synthesis and characterization of zirconium(IV) molybdosulphosalicylate, multi-walled carbon nanotubes and polypyrrole based ternary nanocomposites: Adsorption and lead sensing studies

Abstract

The present paper reports the facile synthesis of zirconium molybdosulphosalicylate cation exchanger [Zr(IV)MoS] and its successive nanocomposites of polypyrrole bearing different weight percent of multiwalled carbon nanotubes (MWCNTs) using a simple sol-gel approach via in-situ oxidative polymerization (ZP, 1-ZMP and 2-ZMP having nil, 0.1 and 0.25 g MWCNTs respectively). The nanocomposites were systematically characterized by FTIR, SEM, TEM, XRD and TGA. The spectral data is indicative of the polymerization of pyrrole on the ZMP nanoparticles. The TEM images also signify the encapsulation of Zr(IV)MoS on pyrrole matrix while MWCNT appears as long threads. The TGA profiles of ZP, 1-ZMP and 2-ZMP are suggestive that as the loading of MWCNT is increased, the thermal stability also gets enhanced. ZP, 1-ZMP and 2-ZMP were also analysed for their adsorption behavior against Ni(II), Cu(II) and Pb(II) ions where maximum absorption efficiency was observed in the case of 1-ZMP nanocomposite. Similarly, the ZP, 1-ZMP and 2-ZMP nanocomposites were also screened for their probable lead sensing application using cyclic voltammetry and the possible mechanism of Pb2+ion detection in the presence of 2-ZMP was also explored.