Synergistic inhibition of peanut-shell-derived lignin and 6-benzylaminopurine on corrosion of Q235 steel in HCl medium

Lignin extracted from cheap and copious peanut shells could act as a corrosion inhibitor for carbon steel in an acid medium. However, the corrosion inhibition effect of lignin is not satisfactory. The combination of lignin with other small organic molecules could be an alternative for improving the inhibition of lignin owing to their synergistic effect. In the current work, the inhibitive ability of lignin extracted from peanut shells combined with 6-benzylaminopurine (BAP) on the Q235 steel surface in 1 M HCl solution was first researched at various concentrations and temperatures via electrochemical methods and surface analysis. The experimental results indicate a synergistic effect of lignin with BAP, which could protect Q235 steel from corrosion effectively.