Electrochemical oxidation of textile azo dye reactive orange 16 on the Platinum electrode

Abstract

This study focused mainly on the color removal of textile azo dye Reactive Orange 16 (RO16) by electrochemical oxidation. The effect of supporting electrolyte (H2SO4 and NaOH), RO16 concentration (from 0.5 to 10 mM) and potential scan rate (between 20 and 500 mV/s) was performed with cyclic voltammetry using platinum (Pt) wire as working electrode. The anodic peak current density was linear to RO16 concentrations. This allows the lowest concentrations to be determined voltammetrically in the two electrolytic media, acid (H2SO4 1 M) and alkaline (NaOH 0.1 M). Linearity between the current density and the square root of the potential scan rate was observed in both electrolytes. This means that the electrochemical reaction at the electrode-electrolyte interface is controlled by the diffusion process. The slope of the logarithm of peak current density versus the logarithm of potential scan rate was found to be 0.43 for RO16 in H2SO4 and 0.48 in NaOH these values of slop are close to the thеoretical value of 0.5 which confirms the diffusion process. The removal efficiency of the dye in acid electrolyte reached 40%, while it is 18% in the basic media after 4 hours of electrolysis by chronoamperometry.