Simultaneous determination of Cd(II) and Pb(II) using electrode modified by FeAl2O4-AlOOH-reduced graphene oxide hybrids

Abstract

A new kind of electrode composed of FeAl2O4 nanoparticles, γ-AlOOH, and reduced graphene oxide (rGO) was prepared for the simultaneous determination of Cd(II) and Pb(II) in aqueous solution using square wave anodic stripping voltammetry (SWASV). γ-AlOOH was employed to modify rGO to obtain a platform for distributing FeAl2O4 particles uniformly. The phase and structure of the FeAl2O4-AlOOH-rGO composites were characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD) patterns, and Fourier-transform infrared spectroscopy (FTIR). The electrochemical properties were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicate that the combination of AlOOH and rGO may provide a better electrochemical behavior due to excellent adsorption ability of AlOOH and large surface area of rGO. Electrochemical parameters such as supporting electrolyte, pH value, deposition potential, deposition time, and concentration of Bi3+ affecting the deposition and stripping of metal ions were also studied. The electrode exhibits wider detection linear range and lower determination limit toward simultaneous determination of Cd(II) and Pb(II). It further possesses good reproducibility and stability.