Magnetite Decorated Multiwalled Carbon Nanotube Based Supercapacitor for Arsenic Removal and Desalination of Seawater

A new type of flexible carbon fabric supported magnetite multiwalled carbon nanotubes (Fe3O4-MWNTs) nanocomposite based supercapacitor was fabricated for the removal of high concentration of arsenic and desalination of seawater. MWNTs were synthesized by a chemical vapor deposition (CVD) technique, purified by air oxidation and acid treatment followed by further functionalization. Decoration of magnetite (Fe3O4) nanoparticles over functionalized MWNTs surface was done by a chemical technique. Fe3O4-MWNTs nanocomposite was characterized using different characterization techniques. Electrochemical activity of the nanocomposite was analyzed for arsenite and arsenate ions containing water as well as for seawater by using cyclic voltametry (CV). Adsorption isotherms and kinetic characteristics of sodium, arsenate, and arsenite ion removal were studied. Performance of the filter made up of nanocomposite-based electrodes was examined by an inductive coupled plasma optical emission spectroscopy (ICP-OES) technique. The present study shows the novel nature of the nanocomposite, which can remove both types of arsenic ions (arsenate and arsenite) and salt from seawater. High desalination efficiency (removal of sodium, magnesium, and calcium) of seawater and repeatability for the simultaneous removal of arsenic (both arsenate and arsenite) and sodium have been demonstrated in the present work.