Soybean extract firstly used as a green corrosion inhibitor with high efficacy and yield for carbon steel in acidic medium

The soybean extract (SE) was firstly investigated for corrosion inhibition characteristics on carbon steel in sulfuric medium. The weight loss and electrochemical methods were used to research the inhibition performance and adsorption properties of SE in combination with halide ions. Results showed the SE + I- inhibitors possessed outstanding corrosion inhibition efficiency, ~98%. Furthermore, the effective compound of SE was identified to be responsible for the corrosion inhibition effect. The AFM, water contact angle and XPS measurements confirm the formation of a corrosion inhibitor film on carbon steel. Combining differential capacitance curves, corrosion inhibition mechanism was further interpreted. Good inhibition efficiency, green extract solvent, facile extraction procedure, high yield and environment sustainability, endow SE as novel corrosion inhibitor with a promising future for industrial application.