Benzimidazole derivatives as novel inhibitors for the corrosion of mild steel in acidic solution: Experimental and theoietical studies

The inhibition effects of three kinds of benzimidazole derivatives (2-mercaptobenzimidazole (MBI), 2-thiobenzylbenzimidazole (TBBI) and 1-butyl-2-thiobenzylbenzimidazole (BTBBI)) on the corrosion of mild steel in 1 M HCl solution were studied by weight loss and electrochemical measurements, and theoretical calculations. It is found that these compounds act as mixed type inhibitors with predominant cathodic effectiveness and exhibit high inhibition efficiencies with the order: BTBBI > TBBI > MBI. Molecular dynamics simulations reveal that these benzimidazole derivatives adsorb on Fe (1 1 0) surface in flat orientation. The theoretical calculations are in good accordance with the weight loss and electrochemical measurements. (C) 2019 Elsevier B.V. All rights reserved.