Publication

Abstract : The adsorption performance and anticorrosion activity of nitroxoline (NHQ) on copper were evaluated by gravimetric method in 1.0, 2.0 and 3.0 M nitric acid solutions and by electrochemical techniques namely electrochemical impedance spectroscopy (EIS), Tafel polarization (TP) and linear polarization (LP) in 1.0 M nitric acid solution. In all four methods, it was observed that the percentage of inhibition efficiency increases with increasing inhibitor concentration from 50 to 300 ppm. TP curves indicate that the antibiotic drug NHQ acts as mixed-type inhibitor. EIS studies showed that the charge transfer resistance increases with inhibitor concentration. The thermodynamic parameter ΔG0ads confirmed a physisorption mechanism. The inhibitor adsorption was spontaneous and it obeyed Langmuir adsorption isotherm. The formation of adsorbed layer on the copper metal surface was confirmed by SEM, EDX, FT-IR and AFM techniques.