In-depth insight into the corrosion inhibition mechanism of Panax notoginseng leaf extract on the corrosion of mild steel in an acidic environment

Abstract

An eco-friendly corrosion inhibitor, Panax notoginseng leaf extract (PNLE), was systematically studied via electrochemical experiments, surface analysis, and first-principles calculations. Electrochemical measurements show that PNLE exhibits remarkable inhibition performance toward mild steel in 1 M HCl medium, with a peak inhibition efficiency of 99.1% at 400 mg L⁻¹. Theoretical calculations corroborate the generation of Fe–O, Fe–N, and Fe–C bonds at the PNLE–steel interface, which furnishes unambiguous evidence for chemisorption. Overall, PNLE exhibits outstanding corrosion inhibition performance and has a wide range of raw material acquisition pathways and simple extraction process operations. It is a corrosion inhibitor of high development value in the industrial field.