Cyclic Voltammetric Study of Chromium (VI) and Chromium (III) on the Gold Nanoparticles-Modified Glassy Carbon Electrode

The chromium (VI) and chromium (III) depositions on the gold nanoparticles (AuNPs)-modified glassy carbon electrode (GCE) from aqueous solutions were studied by means of cyclic voltammetry technique. The deposition processes were investigated at +25 °C. The anodic and cathodic scannings were recorded within the potential range of -500 to 1500 mV. The scan rate and multiple cycling were carried out to examine the behavior of the electroactive species on the electrode surface. The logarithmic of the plot between Ip and V reflected a diffusion controlled by the irreversible redox reaction of Cr (III) and an adsorption-driven process. These results strongly suggested that the irreversible redox reaction of Cr (VI) was controlled by the diffusion step.