Synthesis, characterization, photolytic degradation, electrical conductivity and applications of a nanocomposite adsorbent for the treatment of pollutants

Abstract

A new semi-crystalline nanocomposite cation exchanger has been synthesized by the sol–gel method and characterized on the basis of FTIR, XRD, SEM, TEM, TGA and CHNO analysis. The ion-exchange material was synthesized at pH 1.0 and shows an ion exchange capacity of 1.37 meq g⁻¹ for Na⁺ ions. The composite material exhibits improved ion exchange capacity along with chemical and thermal stability. It can be used at up to 300 °C, with 98% retention of its initial ion-exchange capacity. The conductivity of different samples of composite material was found to be in the semiconducting range, which indicates that the conductivity of the samples is highly dependent on the % of inorganic precipitate. The photochemical degradation of industrial dye was also investigated using this composite. The distribution coefficient studies of metal ions on the material were performed in different concentrations of surfactants (Tween 80, CPC) and on mixtures (solvent + surfactant). On the basis of K_d values the material was found to be selective for Hg(II), Bi(III), Zr(IV) and Pb(II) ions. Some analytically important separations of metal ions in synthetic mixtures and real samples were achieved on the column of this exchanger. The limits of detection for Pb(II), Zn(II) and Hg(II) were found to be 0.32, 0.92 and 0.50 μg L⁻¹ and the limits of quantification were found to be 1.07, 3.08 and 1.69, respectively. Besides the ion-exchanger, polyaniline Ti(IV)As composite material has been successfully applied for the photochemical degradation of industrial dye as well as a conducting material.