Investigation of the inhibition effect of 5-(3, 4, 5-Trimethoxyphenyl)-2H-tetrazole on mild steel corrosion in 1 M HCl solution

In this work, the inhibition performance of 5-(3, 4, 5-Trimethoxyphenyl)-2H-tetrazole on mild steel corrosion was investigated in 1 M HCl solution. Scanning electron microscopy (SEM), electrochemical impedance spectroscopy(EIS) and polarization were used to determine its inhibition effects. Different concentrations of the inhibitor and temperatures effect were investigated in 1 molar acid chloride solution. Polarization studies showed that the inhibitor affected mild steel in 1 M HCl solution by two types of interaction, chemisorption and physisorption. The Gibbs free energy of this inhibitor was -29.91 kJ.mol-1. Adsorption isotherm investigation of the inhibitor on mild steel proved that the adsorption of the inhibitor obeys the Langmuir adsorption isotherm. The results showed that increasing the inhibitor concentration up to 300 ppm increased the inhibition percentage up to 90%. The impedance results indicated increasing of the corrosion resistance in the presence of the inhibitor more than 10 times compared to the absence of the inhibitor.