Extract of photinia leaves as an effective corrosion inhibitor of carbon steel in 1 M HCl solution

Traditional corrosion inhibitors, such as heavy metal-containing compounds or toxic organics, have long faced two critical challenges: achieving environmentally friendly production and enabling resource recyclability. Developing high-efficiency corrosion inhibitors using renewable resources through safe and green methods has emerged as a pivotal strategy for sustainable progress. In this study, a novel green corrosion inhibitor was synthesized via hydrothermal extraction from Photinia leaves. The inhibition efficiency of Photinia leaves extracts (PLEs) for carbon steel in 1 M HCl was systematically evaluated using electrochemical measurements, surface characterizations, and computational simulations. Results demonstrated that PLEs exhibited a concentration-dependent inhibition performance, reaching 97.68% efficiency at 1000 mg/L. Structural characterization revealed that PLEs contain bioactive molecules such as polyphenols, flavonoids, and alkaloids, which are rich in N- and O-heteroatoms capable of coordinating with iron to form protective films. Microscopic morphology analysis confirmed the formation of a dense inhibitor-adsorption layer on the steel surface, effectively shielding it from corrosive attack. Furthermore, quantum chemical calculations and molecular dynamics simulations elucidated the adsorption mechanisms, highlighting the role of electron donation and interfacial bonding. This work provides both experimental and theoretical insights into the development of plant-derived inhibitors, addressing the limitations of traditional counterparts while aligning with green chemistry principles.