Corrosion Inhibition of Eco-Friendly Agricultural Waste-based Prinsepia utilis Royle Meal Extract for Cold-Rolled Steel in Acidic Media: Experimental and Simulation
Abstract
Utilizing agricultural and forestry waste as plant-derived corrosion inhibitors can alleviate resource scarcity and environmental pollution. In this study, Prinsepia utilis Royle meal extract (PURME) was extracted via 60% ethanol reflux, and its corrosion inhibition on cold-rolled steel (CRS) in 0.5 M H₂SO₄ and 1.0 M HCl was evaluated through weight loss, electrochemical tests, FTIR (Fourier Transform Infrared Spectroscopy), LC-MS (Liquid Chromatography-Mass Spectrometry), UV-vis (Ultraviolet-Visible Spectroscopy), and conductivity measurements. Surface analysis employed XPS (X-ray Photoelectron Spectroscopy), AFM (Atomic Force Microscopy), contact angle, and TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry). The results demonstrated that PURME achieved inhibition efficiencies of 89.25% in H₂SO₄ and 91.28% in HCl at 20°C, conforming to the Langmuir adsorption model. Electrochemical tests revealed PURME as a mixed-type inhibitor with predominant cathodic inhibition. LC-MS identified key active components, such as chenodeoxycholic acid and linolenic acid, while FTIR, XPS, and TOF-SIMS confirmed the adsorption of functional groups (-C-N, -C-O, -OH) onto CRS surfaces. AFM and contact angle measurements further validated PURME's corrosion inhibition efficacy. Computational analyses (QC (quantum chemical) calculations and MD (molecular dynamics) simulations) revealed that reactive sites were primarily localized on -COOH, -OH, and C=C groups, elucidating the adsorption mechanism. These findings systematically highlight PURME's potential as an eco-friendly corrosion inhibitor in acidic environments.