Evaluation of corrosion inhibition performance of thiazolidine-2,4-diones and its amino derivative: Gravimetric, electrochemical, spectroscopic, and surface morphological studies

[Display omitted] To produce effective, less expensive molecules with minimum impact on the environment, the study aims to develop green corrosion inhibitors, which can significantly protect mild steel during its pickling and descaling treatment. Therefore, the present study describes the corrosion inhibition performance of two thiazole derivatives, namely thiazolidine-2,4-diones and its amino derivative 2-aminothiazolidin-4-one designated as TZD, and AT, respectively mild steel in 5%HCl solution through gravimetric measurement, electrochemical measurement (open circuit potential, electrochemical Impedance Spectroscopy, and potentiodynamic polarization). The spectroscopic measurement like FT-IR, UV–vis, X-ray photoelectron spectroscopy (XPS) along with surface morphological analysis like scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and atomic force microscopy (AFM) was also carried out. Gravimetric studies suggested that the inhibitory effects of the proposed compounds improves with an increase in the concentration of TZD and AT and solution temperature, having the most significant efficiencies of 98.0% and 99.7%, respectively, at 5 × 10−4 M at 60 °C. According to electrochemical tests, the analyzed inhibitor molecules function as mixed-type corrosion inhibitors and improve corrosion charge transfer resistance. AFM, SEM, and EDS investigations indicated that TZD and AT molecules adhere and construct a surface protective layer.