The effective determination of Cd(ii) and Pb(ii) simultaneously based on an aluminum silicon carbide-reduced graphene oxide nanocomposite electrode.

Abstract

A platform for the simultaneous determination of Cd(ii) and Pb(ii) in aqueous solution has been applied based on an aluminum silicon carbide-reduced graphene oxide nanocomposite (Al4SiC4-RGO) modified bismuth film glassy carbon electrode (GCE) using square wave anodic stripping voltammetry (SWASV) for the first time. The Al4SiC4-RGO nanocomposite electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Compared with the Al4SiC4 modified GCE and bare GCE, the electrochemical performance of the Al4SiC4-RGO nanocomposite electrode is obviously enhanced resulting from the synergistic effects of Al4SiC4, RGO and bismuth film. The chemical and electrochemical parameters that exert an influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH values, concentrations of Bi3+, deposition potentials and deposition times, were carefully studied. Under optimal conditions, a linear relationship exists between the currents and the concentrations of Cd(ii) and Pb(ii) in the range of 50 to 2700 μg L-1. The limits of detection (S/N = 3) are estimated to be 1.30 μg L-1 for Pb(ii) and 2.15 μg L-1 for Cd(ii). Compared with the related work reported in the literature, the analytical performance in this work has a lower determination limit and a wider detection linear range. In addition, this electrode also exhibits good stability and reproducibility. These results imply that the Al4SiC4-RGO nanocomposite might be a promising candidate for practical applications in the electrochemical detection of metal ions.