Enhanced corrosion mitigation potential of quinoline derivative for Q235 steel in strong acidic solution: an integrated experimental and computational approach

Abstract

This study screened the corrosion mitigation potential of quinoline derivative (QDCC) for Q235 steel protection in a 5 M HCl medium. The techniques used for examination include weight loss, electrochemical (100 mg/L to 400 mg/L), SEM/EDX, AFM, XPS, DFT, and MD. As QDCC doses increased, the corrosion prevention capacity was successfully improved. The PDP findings showed that QDCC functions as a mixed-type inhibitor, promoting the inhibition of both cathodic and anodic processes. The maximum and minimum charge transfer resistance (R_ct) and double-layer capacitance (C_dl) are 515.0 Ω cm⁻¹ and 186.0 μF/cm² with the addition of QDCC, indicating the corrosion inhibition mitigation. Temkin is the most accurately fitted isotherm that illustrates the chemical adhesion potential of QDCC upon the Q235 steel with ΔG^o_ads equals to − 43.49 kJ/mol. The surface study approaches like SEM/EDX, AFM, and XPS showed that the QDCC is strongly adhered over Q235 steel surface. The computation examination, which included DFT and MD, showed that neutral-QDCC forms are strongly adsorbing compared to protonated ones.