Anticorrosive effectiveness of mild steel by dragon scale fern (Drymoglossum piloselloides L.) leaf extract in hydrochloric acid medium: A combined experimental and computational approach

The inhibition of mild steel corrosion in 1 M hydrochloric acid (HCl) solution by dragon scale fern (Drymoglossum piloselloides L.) leaf extract (DSFLE) was studied using the weight loss method, potentiodynamic polarization, Fourier Transform Infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectrophotometry, and microscopy.The results showed that the corrosion rate of mild steel increased with increasing temperature and decreased with increasing extract concentration.The inhibition efficiency was also proportional to temperature and extract concentration.Based on the weight loss method, the highest inhibition efficiency was 91.01%with the addition of 10 g/L extract at a temperature of 60C.Thermodynamic parameters were calculated to determine the corrosion inhibition mechanism.The adsorption of DSFLE on the mild steel surface followed the Langmuir adsorption isotherm.The potentiodynamic polarization value showed that the dragon scale fern extract was a mixed inhibitor.FTIR and UV-Vis spectrophotometry analysis demonstrated the interaction between DSFLE and the mild steel surface.Microscopic analysis showed that DSFLE could reduce corrosion on the mild steel surface.The primary constituents of DSFLE were tested for corrosion inhibition efficiency using quantum chemical parameters and interaction energies.According to the experimental findings, N-benzoyl-L-phenylalaninol and kaempferol were the highly effective inhibitors.Both molecules were chemically adsorbed strongly on the surface by forming N-Fe 2+ and O-Fe 2+ bonds.The EHOMO, ELUMO, E, and other electronic parameters for various protonated and non-protonated forms of N-benzoyl-L-phenylalaninol and kaempferol compounds studied showed a good correlation with the efficiency of mild steel corrosion inhibition.