Corrosion Inhibition and Adsorption Characteristics of API 5L X-52 Steel by an Antibiotic Drug in HCl Solution

The corrosion inhibition potential of an antibiotic drug called moxifloxacin for API 5L X-52 steel in 2 M HCl solution was investigated using experimental (gravimetric and electrochemical impedance spectroscopy) and theoretical approaches. Results obtained from gravimetric and electrochemical impedance spectroscopy measurements revealed that moxifloxacin inhibit the corrosion of steel, and recorded instantaneous maximum inhibition efficiency of 88% and 82.7% respectively at 303 ±1 K. Statistical consideration revealed that there was no significant difference between the two methods employed. The adsorption behavior of the inhibitor was best described by the Langmuir adsorption isotherm. Dipole moment calculated from quantum chemical calculation method was found to be in good agreement with those reported for some good corrosion inhibitors. The sites for nucleophilic and electrophilic attacks correspond to the atom N3, C12, C15, C22, C24, C27, O28 and N3, N8, C11, C13, C15, O28 respectively.