Application of expired drugs in corrosion inhibition of mild steel

Present work deals with the investigation of corrosion inhibition of mild steel using two expired drugs namely Atenolol and Nifedipine in 1 M HCl solution. Their inhibition properties were evaluated using electrochemical, scanning electron microscopy (SEM) and DFT methods. Atenelol and Nifidipine showed efficiency of 91.30 and 93.91% at low concentration of 200 ppm respectively. Polarization study reveals that the expired drugs inhibit corrosion of mild steel by suppressing both anodic and cathodic reactions occurring on the mild steel surface thus acting as mixed type inhibitors. EIS study shows that the investigated drug increases the polarization resistance by adsorbing on the metal/electrolyte interface. The electrochemical results were well supported by SEM as well as DFT study.