Electrochemical Effect of Different Modified Glassy Carbon Electrodes on the Values of Diffusion Coefficient for Some Heavy Metal Ions

Glassy carbon electrode (GCE) was modified with carbon nanotubes (CNT), C60 and activated carbon (AC) by mechanical attachment method and solution evaporation technique to preparation CNT/GCE, C60/GCE and AC/GCE, these electrodes were modified in Li+ solution via cyclic voltammetry (CV) potential cycling to preparing CNT/Li+/GCE, C60/Li+/GCE and AC/Li+/GCE. The sensing characteristics of the modified film electrodes, demonstrated in the application study for different heavy metal ions such as Hg2+, Cd2+, and Mn2+. Cyclic voltammetric effect by chronoamperometry (CA) technique was investigated to determination the diffusion coefficient (Df) values from Cottrell equation at these ions. Based on Cottrell equation (diffusion coefficient) of the redox current peaks of different heavy metal ions at different modified electrodes were studied to evaluate the sensing of these electrodes by the diffusion coefficient values. The modification of GCE with nano materials and Li+ act an enhancement for the redox current peaks to observe that the diffusion process are high at CNT/Li+/GCE, C60/Li+/GCE and AC/Li+/GCE, but it has low values at unmodified GCE.