Accelerating corrosion inhibitor discovery through computational routes: a case of naphthalene 1-thiocarboxamide

The conventional approach to the discovery of corrosion inhibitors is time-consuming and resource-intensive. This study demonstrates a first-principles DFT-based workflow to accelerate rational design and discovery of corrosion inhibitors for mild steel in acidic media. Screening sulfur-containing molecules via quantum chemical descriptors identified naphthalene 1-thiocarboxamide (NTC) with the lowest ELUMO and Egap, indicating strong inhibition potential. Explicit adsorption studies show strong chemisorption of NTC on Fe (001) with multiple Fe–C/N/S covalent bonds, and DFT surface coverage studies indicate formation of a compact monolayer. Gravimetric, potentiodynamic polarization, and electrochemical impedance spectroscopy experiments confirm NTC as a remarkable inhibitor for mild steel in 1 N HCl at room temperature and 60 °C, achieving high inhibition efficiencies even at 1 mM concentration.

Dharmendr Kumar, Venkata Muralidhar K, Vinay Jain, Beena Rai