Voltammetric and amperometric determination of iodate using a modified glassy carbon electrode based on PW12/MOF/P@ERGO nanohybrid

Abstract

A nanocomposite of tungstophosphoric acid (PW12), metal-organic framework (MOF), and graphene oxide (GO) (PW12/MOF/GO) was electrodeposited at −1.5 V by amperometry technique from a suspension of PW12/MOF/GO nanocomposite in 0.01 M H3PO4. The synthesized PW12/MOF/GO was characterized by Fourier-transform infrared spectroscopy, X-ray powder diffraction, Transmission electron microscopy, inductively coupled plasma-optical emission spectrometry, and Brunauer-Emmett-Teller analytical techniques. The morphology of PW12/MOF/P@ERGO/GCE was evaluated by FE-SEM images and energy dispersive spectroscopy. The modified GCE was an electrochemical sensitive surface for IO3− sensing. The PW12/MOF/P@ERGO/GCE had a higher reductive current in the electro-reduction of IO3− than bare GCE. The proposed sensor by amperometric experiments displayed a linear range of 10–2000 μM with a limit of detection (LOD) of 3.86 μΜ, a sensitivity of 20.0 μA mM−1, and excellent selectivity for IO3− detection in the presence of other potential interfering species. Moreover, the modified GCE was successfully applied for IO3− detection in mineral water and commercial table salt.

Keywords

• Polyoxometalate (POM)
• Metal- organic framework (MOF)
• Electrochemically reduced graphene oxide (ERGO)
• Electrocatalyst
• IO3− electro-reduction