Enhanced corrosion resistance of carbon steel in an aggressive environment by a recently developed pyrazole derivative: Electrochemical, SEM/XPS/AFM, and theoretical investigation

In this paper, a new pyrazole derivative, namely, (2-(((3,5-dimethyl-1H-pyrazol-1-yl)methyl)amino)-5-nitrophenyl)(phenyl) methanone (2-DPM) was uniquely used as an inhibitor of corrosion for carbon steel (C-S) in acidic solution (1 M HCl). Numerous techniques include electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), surface morphology analysis (SEM), energy-dispersive X-ray spectrometry (EDX), atom force microscopy (AFM), angle of contact, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible analysis. Molecular dynamic simulations (MDs) and quantum chemical computations (DFT) were utilized to assess the 2-DPM ability. The results show that the inhibitor, acting in a mixed inhibitory mode, considerably reduces the incidence of C-S corrosion by protecting the metal surface with an effective protective layer. The chemically adsorbed novel pyrazole (2-DPM) molecule has an improved corrosion performance of nearly 96% at 303 K, which is supported by EIS and theoretical analyses. The Langmuir isotherm model was shown to regulate the adsorption of 2-DPM on the surface of C-S. Finally, there is a strong correlation between theoretical research and experimental findings.