Corrosion inhibition of mild steel in 1 M HCl solution by ethanolic extract of eco-friendly Mangifera indica (mango) leaves: Electrochemical, molecular dynamics, Monte Carlo and ab initio study

Abstract

The mild steel corrosion inhibition in 1 M HCl solution containing Mangifera indica (mango) (M. indica) leaves extract was examined by electrochemical and surface studies. The presence of many active components with aromatic and oxygen containing functional groups in the extract of M. indica was shown by transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometry (UV–Vis). Results revealed that with increasing inhibitor concentration and immersion time the inhibition efficiency increased and reached the maximum value of 92% after 24 h in the presence of 1000 ppm inhibitor. It was shown that in the presence of M. indica extract both iron anodic dissolution rate and cathodic hydrogen evolution reaction rate efficiently decreased reflecting a mixed inhibition action. The inhibitor adsorption on mild steel followed a Langmuir isotherm. Surface studies revealed the inhibitor film formation on the iron surface resulting in the surface damage decline and increase of hydrophobicity. Also, the theoretical results confirmed the inhibitor adsorption on the steel surface through its reactive sites.