Inhibitive potential of benign Caesar-weed leaves extract (CWLE) as corrosion inhibitor of aluminium in H2SO4 phase

Caesar-weed leaves extract (CWLE) was employed as inhibitor on the corrosion of aluminium in 0.5M H2SO4. The process was achieved by means of weight loss technique. The results revealed that inhibition efficiency increased with increase in concentration of the inhibitor but decreased with increase in temperature. Apparent activation energy increased with inhibitor concentration indicating the effectiveness of CWLE to retard the corrosion process by increasing the energy barrier. The corrosion process followed first order kinetics with correlation coefficients (R2) > 0.94. The data obtained were fitted into various adsorption isotherms, though Langmuir isotherm was found to be the best fit. The thermodynamic parameters revealed that the extract adsorption on aluminium surface was spontaneous, exothermic, and supported physical adsorption process.