Corrosion inhibition effects of a novel ionic liquid with and without potassium iodide for carbon steel in 0.5 M HCl solution: An experimental study and theoretical calculation

Corrosion inhibition of carbon steel in 0.5 M HCl solution by novel ionic liquid (IL),1.1'-(1,4-phenylenebis(methylene))bis(3-(carboxymethyl)-1H-imidazol-3-ium) chloride with and without KI was systematically investigated by electrochemical tests, surface and solution analysis as well as theoretical calculation. Results showed that IL can suppress anodic and cathodic reaction by adsorption onto the steel surface, which follows the Langmuir adsorption isotherm. The inhibition efficiency increases with increasing IL concentration. Addition of KI to IL increases the maximum inhibition efficiency of 94.8% to 96.2% when using IL:KI = 1:1. Theoretical inhibition efficiency results correlate well with experimental observations. (C) 2018 Elsevier B.V. All rights reserved.