A novel l-histidine based ionic liquid (LHIL) as an efficient corrosion inhibitor for mild steel

Jing Wang; Chengbao Liu; Bei Qian

doi:10.1039/d1ra08275b

A novel l-histidine based ionic liquid (LHIL) as an efficient corrosion inhibitor for mild steel

RSC Adv. 2022 Jan 21;12(5):2947-2958. doi: 10.1039/d1ra08275b. eCollection 2022 Jan 18.

Authors

Jing Wang¹, Chengbao Liu², Bei Qian³

Affiliations

¹ Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment 37 Miaoling Road Qingdao 266061 China.
² College of Materials Science and Engineering, Shandong University of Science and Technology Qingdao 266590 China.
³ College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University Qingdao 266109 China bqian@qau.edu.cn.

Abstract

A novel l-histidine based ionic liquid (LHIL) was developed and successfully synthesized. Its structure was confirmed by Fourier-transform infrared spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, ¹H-NMR and high-resolution mass spectrometry. The outstanding corrosion inhibition effect of the LHIL on mild steel in 1 M hydrochloric acid was thoroughly evaluated by Tafel plots, electrochemical impedance spectroscopy, and localized electrochemical strategies. The results revealed that the corrosion of mild steel was effectively suppressed by the adsorption of LHIL on its surface, and the best inhibition efficiency reached 98.8%. The adsorption behavior of LHIL on steel obeyed the Langmuir adsorption isotherm, which involved both chemisorption and physisorption. Theoretical calculations indicated the strong chemisorption of LHIL on steel, as proved by the low energy gap (ΔE = 0.0522 eV) and high binding energy (E _binding = 303.47 kcal mol^-1), which clearly confirmed the effectiveness of LHIL for steel protection.