Computational and experimental investigation of anticorrosive potential of Panthenol for mild steel in 1 M hydrochloric acid solution

An investigation into how Panthenol affects the corrosion of mild steel in 1 M hydrochloric acid was carried out, specifically its adsorption behaviour and the mechanism by which it inhibited corrosion and for this electrochemical analysis techniques, weight loss, scanning electron microscopy, atomic force microscopy, contact angle measurements has been used. Also, the theoretical study which includes study of global reactivity descriptors E-HOMO, E-LUMO, energy gap (Delta E) etc. and molecular dynamics (MD) simulations in aqueous phase have been used to simulate the real situation. This study confirmed a high inhibition efficacy of 90 % at a concentration of 400 ppm. The electrochemical analysis demonstrated that as the concentration of Panthenol increased, there was an apparent reduction in the value of j(corr) and an upsurge in the value of R-ct. In case of potentiodynamic polarization, the value of j(corr) came out to be 144 mu A cm(-2) and in electrochemical impedance spectroscopy, the value of R-ct came out to be 125.32 ohm cm(2) at 400 ppm. The surface morphological investigations revealed the deposition of an extensively protective coating on the mild steel surface. Calculated values of roughness (average and root mean square in nm) in the present study shows a reduction in roughness (in the acid the values were 401 nm, 518 nm respectively and acid with Panthenol, the values were 56.9 nm and 82.5 nm, respectively). In quantum chemical calculations, the calculated value of Delta E came out to be 5.098, validating the strong tendency of inhibitor to retard the corrosion. The investigation revealed that Panthenol is an effective and environmentally friendly inhibiting agent of corrosion for mild steel in a 1 M HCl solution. Additionally, the theoretical findings reiterated the experimental results obtained in this study.