LAUSR

Abstract Hydrogen bonded interaction and synergistic effect on the corrosion protection properties of alkyl benzimidazoles and semicarbazide pair on mild steel in hydrochloric acid at 303, 308 and 313 K have been studied by polarization, electrochemical impedance spectroscopy, adsorption, surface studies and basic computational calculations. The inhibition efficiencies and the global chemical reactivity relate to total energy, EHOMO, ELUMO and gap energy (ΔE). Semicarbazide interacts with alkyl benzimidazoles up to an average bond length of 1.9296 A. This interaction may be due to the formation of a hydrogen bond between semicarbazide and alkyl benzimidazoles. This synergistic interaction offer extended inhibition efficiency toward mild steel in hydrochloric acid. The corrosion inhibition efficiencies and the global chemical reactivity relate to total energy, EHOMO, ELUMO and gap energy (ΔE).