High-value utilization of invasive plant-Alternanthera philoxeroides extract in corrosion inhibition of aluminum

Aluminum plays important roles in infrastructure construction, aerospace, transportation, and industries for its excellent performance. Hence, exploring green aluminum corrosion inhibitors with high efficiency is becoming a research hot spot. In this study, the invasive weed of Alternanthera philoxeroides which seriously threatens the ecological environment was designed as a precursor to prepare Alternanthera philoxeroides extract (APE) as a plant corrosion inhibitor via ultrasonic extraction . The weight loss method and electrochemical measurement were used to study the inhibition effect of APE on aluminum in hydrochloric acid . The results showed that the maximum inhibition efficiency of APE is up to 96 % in 1.0 M HCl solution at 20 °C. Besides, it further proved that the physical and chemical adsorption worked simultaneously, and the APE acted as a mix-type inhibitor to improve good inhibition efficiency to the Al via the geometric coverage effect. A series of characterization and theoretical analyses confirmed that APE molecules exhibit high inhibiting efficiency to aluminum corrosion in HCl solution by laying horizontally and forming an adsorption film on the surface of the aluminum. The outcomes of this study may offer valuable insights into the treatment of invasive plants for their high-value utilization.