Electrochemical Studies of Adsorption and Inhibitive Performance of Basic Yellow 28 Dye on Mild Steel Corrosion in Acid Solutions

Organic corrosion inhibitors are widely used to control the corrosion of different metals in various corrosive solutions. The inhibition performance of Basic yellow 28 (BY28) dye for mild steel corrosion was investigated in 0.1 M HCl solution and in a solution of 0.1 M HCl and 1% NaCl. Two electrochemical methods including Tafel polarization and electrochemical impedance spectroscopy (EIS) measurements were used. The corrosion parameters as well as inhibition efficiencies were obtained for different concentrations of inhibitor. The inhibition efficiencies showed that the BY28 dye acts as a good corrosion inhibitor for mild steel in both solutions. The studies on adsorption isotherm of the dye on mild steel proved that the adsorption of BY28 obeys the Langmuir adsorption isotherm. The average value of –ΔGads in both solutions was more than 20 and a little less than 40 kJ mol–1. Therefore, both chemisorption and physisorption phenomena were involved in the adsorption of the studied dye on mild steel surface.