Corrosion inhibition performance of Punica granatum L extract on Q235 steel in H2SO4 environment: Electrochemical, morphological, and quantum chemical studies

Abstract

The corrosion inhibitor used in this experiment was the extract of Punica granatum L (PGLE), which was obtained using the pure water extraction method. The inhibition performance of PGLE on Q235 steel in H2SO4 environmental was investigated using electrochemical methods, morphology studies and quantum chemical calculation. The corrosion inhibition properties of PGLE were found to be excellent, with a corrosion inhibition efficiency of approximately 95% at 200 mg/L, and it exhibits characteristics of a mixed-type corrosion inhibitor. The electrochemical impedance (EIS) test revealed a remarkable increase in the charge transfer resistance with the increment of PGLE concentration, and the surface of Q235 steel was covered by a tight and well-organized protective layer of PGLE. The surface morphology test indicates a noticeable decrease in the average surface roughness upon the adsorption of PGLE extract onto the Q235 steel. According to the adsorption isotherm analysis, the adsorption behavior of PGLE on Q235 steel conformed to the Langmuir adsorption. Additionally, adsorption might be physical or chemical. Quantum chemical calculations also showed that PGLE has excellent corrosion inhibition properties.