Polyaniline - BiVO4 nanocomposite as an efficient adsorbent for the removal of methyl orange from aqueous solution

Herein, we report the synthesis of Polyaniline - BiVO4 nanocomposites by in-situ oxidative polymerization using aniline monomer in the presence of hydrochloric acid and bismuth vanadate nanosheets. The physiochemical properties of the adsorbents were characterized by X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy, transmission electron microscopy (HR-TEM) and RAMAN spectroscopy. TEM images confirmed the formation of BiVO4 nanosheet on the PANi matrix. The surface area analysis showed that the PANi - BiVO4 nanocomposites have a high surface area (16.58 and 19.58 m(2)/g) than the PANi nanofiber (9.14 m(2)/g). The adsorption behavior of PANi and PANi - BiVO4 nanocomposites were evaluated by monitoring the adsorption of methyl orange dye within the time interval of 2 h. The PANi - BiVO4 nanocomposite shows 99% of adsorption efficiency which is higher than that of pure PANi (70%). The pseudo-first-order kinetics and Langmuir isotherm model represents the MO adsorption on PANi - BiVO4 was monolayer sorption and the adsorption sites were homogeneous. The reusability of the as-prepared nanocomposite was analyzed and it shows 78% of adsorption after five cycles.