Corrosion Inhibition Activity of Cefixime on Mild Steel Surface in Aqueous Sulphuric Acid

Interaction of pharmaceutically active drug Cefixime on mild steel surface in 0.5 M sulphuric acid solution was studied using gravimetric analysis techniques, Polarization techniques, i.e., Polarization resistance, Tafel polarization, and Electrochemical Impedance Spectroscopy (EIS) techniques. It shows more than 96 % corrosion inhibition efficiency at an ambient temperature of 308 oK on a mild steel surface with a 4.0×10-4 M inhibitor concentration. Gravimetric studies were also conducted at various temperatures and concentration ranges of the testing solution to justify their range of applicability at different practical conditions. an‎d It is found very much suitable for its workings at the normal temperature and lower acid concentration ranges. Adsorption parameters and thermodynamic parameters were calculated from gravimetric analysis data. These parameters were obtained at different temperatures and concentration ranges and reveal that the inhibitor follows the physical adsorption mechanism. Langmuir's adsorption isotherm governs the adsorption of the cefixime molecule. Inhibition of cefixime on the surface of mild steel is supplemented by atomic force microscopy. The result reveals that the inhibited surface has less roughness than the uninhibited surface.