Imidazole-thiazolo[5,4-d]thiazoles as corrosion inhibitors for mild steel in acidic media: experimental and theoretical investigation

Imidazole-substituted thiazolyl[5,4-d]thiazole (TTz) based on two [3.3.0] thiazole-fused rings was synthesized with the advantages of one-step synthesis, easy separation and purification. The inhibition effect and the mechanism on the corrosion behavior of mild steel in 1 M HCl solution was investigated by means of weight loss tests, electrochemical measurements, morphology analysis and theoretical calculation methods. The maximum corrosion inhibition efficiencies of 2-ImTTz and 4-ImTTz are 95.79% and 90.03%, respectively. The measurement of EIS indicated that the corrosion inhibition process is controlled by charge transfer. Quantum chemical calculations revealed the relationship between corrosion inhibition and global reactivity descriptors. Molecular dynamics simulation showed the parallel adsorption of the corrosion inhibitor on the Fe(110) surface in both neutral and protonated forms. The corrosion inhibition mechanism was proposed and discussed.