Structural, electrical, optical and analytical applications of newly synthesized polyaniline based nickel molybdate composite

Highlights: • Synthesis of organic–inorganic conducting nano-composite cation-exchanger. • Average particle size was found to be 76 nm. • The nano-composite was found to be selective for Pb(II), Hg(II) and Th(IV) ions. • The nano composite indicated a band gap of about 3.44 eV showing a weak blue shift compared to 3.37 eV. • The binary separations of metal ions are fairly sharp and reproducible with 90–95% recovery. - Abstract: The synthesis of polyaniline based nickel molybdate nano composite cation exchanger was described by sol–gel method and was explored to study the electrical, optical and analytical applications. The nano composite material was characterized by Fourier Transform Infrared (spectrometer), X-ray diffraction, particle size analyzer, scanning electron microscopy and tunneling electron microscopy. The XRD of nano composite material confirmed the semi-crystalline nature while as particle size analysis as well as TEM depicted average particle size of 76 nm. The partition coefficient studies of different metal ions in the composite were performed in demineralised water and sodium dodecyl sulfate surfactant, and it was found to be selective for Pb(II), Hg(II) and Th(IV) ions. To implement the use of polyaniline Ni(II) molybdate nano composite as adsorbent, some important binary separations of metal ions were performed. SEM analysis showed that the nano composite has random non-preferential orientation with no visible cracks and appeared to be composed of dense and loose aggregation of small particles. The UV–vis spectrum of the nano composite indicated a band gap of about 3.44 eV showing a weak blue shift compared to 3.37 eV for the bulk. Due to their optical and electrical properties, nano composite is promising candidate for use as selectivity of different cations