Locust Bean Gum as a green and novel corrosion inhibitor for Q235 steel in 0.5 M H2SO4 medium

Abstract

Locust Bean Gum (LBG) was studied as a novel and eco-friendly corrosion inhibitor using experimental and theoretical calculation methods. These research methods include open-circuit potential (OCP), potentiodynamic polarization curves (PDP), electrochemical impedance spectroscopy (EIS), surface morphology analysis (AFM and SEM), quantum chemical calculations (QCC), and molecular dynamics simulations (MDS). Potentiodynamic polarization test data shows that when the concentration of LBG is 5 mM at 298 K, the corrosion inhibition efficiency of LBG is 89.8% for Q235 steel in 0.5 M H2SO4 solution. AFM and SEM morphology maps convincingly confirm the data of electrochemical tests. The adsorption of LBG on Q235 steel/solution interface was consistent with Langmuir single-layer model. In addition, theoretical calculations show that LBG can show excellent corrosion inhibition performance.