Seaweed extract as green corrosion inhibitor for carbon steel in hydrochloric acid solution

Abstract

This study aimed to investigate the corrosion inhibition effect of seaweed extract abbreviated as SAE on carbon steel (CS) in 1.0 mol/L hydrochloric acid (HCl) solution. The functional groups in SAE were characterized using Fourier transform infrared (FTIR) spectroscopy. The corrosion inhibition effect of SAE on CS was determined through weight loss experiments, electrochemical tests, and scanning electron microscopy (SEM). Additionally, the composition of the corroded CS surface after immersion in SAE solution was measured through X-ray photoelectron spectroscopy (XPS) analysis. The results indicate that SAE achieves a corrosion inhibition efficiency of 95.0 % for CS in 1.0 mol/L HCl. Furthermore, SAE was identified as a mixed-type inhibitor. The adsorption of SAE on the CS surface follows the Langmuir adsorption isotherm model. UV–visible spectroscopy (UV–vis) studies confirmed that the corrosion inhibition of CS was achieved through the formation of CS-SAE phytoconstituents complex. Moreover, Molecular dynamics simulations (MS) and quantum chemical (QC) calculations were utilized to predict the adsorption properties of several major SAE components and the chemical parameters associated with inhibitory efficiency. This work offers insightful information for developing and applying eco-friendly CI for acid pickling or rust removal from CS.