Anti-corrosion behavior of benzimidazoliumtetrafluroborate ionic liquid in acid medium using electrochemical noise technique

•Corrosion is hindered by [BMEB]+ BF4− ionic liquid using as an inhibitor using noise analysis.•Noise study also gave the reduced current peak in the temperature study confirming sturdy adsorption.•[BMEB]+ BF4− offered surface protection to metal in acid medium, has confirmed by SEM.

In this investigation, the corrosion inhibition behavior of the newly synthesized 3-(4-chlorophenylacylmethyl)-1-ethylbenzimidazolium tetrafluroborate ([BMEB]+ BF4−) in 1 N HCl solution on carbon steel was studied. The electrochemical noise analysis (ENA) has showed that noise resistance (Rn) values and inhibition efficiency were increased with addition of inhibitor concentrations. The adsorption of [BMEB]+ BF4− to bond with carbon surface at metal/HCl solution interface obeyed Langmuir adsorption. The thermodynamic properties were calculated to discuss the adsorption mechanism of corrosion inhibition. Furthermore, the study revealed that the adsorption nature of inhibitor has both physisorption and chemisorption phenomena. Scanning electron microscopic (SEM) study showed a less corroded and smoothened surface morphology of carbon steel, which is due to the formation of protective effect of [BMEB]+ BF4− on the surface. The kinetic study for the corrosion process revealed that the reaction followed first order kinetic in which the reaction depended on concentration of inhibitor.

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