Selective and sensitive detection of Cr(VI) pollution in waste water via polyaniline/sulfated zirconium dioxide/multi walled carbon nanotubes nanocomposite based electrochemical sensor

Abstract

A glassy carbon electrode (GCE) was decorated with polyaniline, ZrO2-SO42− and multi walled carbon nanotubes (MWCNT) nanostructures to supply a sensor devise for Cr(VI) ions measurement, here. The aniline was polymerized in phosphoric acid solution by using peroxydisulfate as an initiator. ZrO2-SO42− nanostructures were synthesized by mono ethanolamine as reducing agent. The fabricated PANI@ZrO2-SO42-@MWCNT nanocomposite (PZrS nanocomposite) was then characterized by XRF, XRD, SEM, EDX and FT-IR techniques. Cyclic voltammograms on bare and modified electrodes show that electro-reduction of Cr(VI) is quicker on PZrS nanocomposite modified electrode. The presence of nanocomposite at the surface of electrode reduces the over potential for Cr(VI) reduction and shifts the potential value about −273 mV. Using differential pulse voltammetry, a detection limit of 64.3 nmol L-1was calculated for Cr(VI). Finally, the designed devise successfully was used to measure Cr(VI) ions in wastewater resulted from the industrial barium chromate production line.