Abstract
The inhibition efficiency of the antibacterial cephalosporin e.g. cefotaxime, cefalexin, cefradine and cefazolin toward the corrosion of iron in 1.0 M HCl was investigated using electrochemical techniques. The results of these techniques indicated that the inhibition efficiency increased with the concentration of inhibitor but decreased with temperature. Potentiodynamic studies proved that the inhibitors act as mixed mode of inhibition and the inhibitor molecules adsorb on the metal-solution interface. The adsorption of the inhibitors on iron surface obeys the Langmuir adsorption isotherm equation. All impedance spectra in EIS tests exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. Inhibition efficiencies obtained from Tafel polarization, charge transfer resistance (Rct) is consistent.