A Comprehensive Study on the Synergistic Effects of Cetyltrimethyl Ammonium Bromide and 1,2,4-Triazole as a Mild Steel Corrosion Inhibitor in an Acidic Environment

This study introduces a novel approach to enhancing corrosion inhibition for mild steel (MS) in acidic environments through the synergistic interaction between 1,2,4-triazole (TRI) and cetyltrimethylammonium bromide (CTAB). Using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques, the combined inhibitory properties of TRI and CTAB were comprehensively investigated in 1 M hydrochloric acid across a range of concentrations and temperatures (20, 30, 40, 50 °C). The results revealed a remarkable increase in inhibition efficiency, reaching 96.3% at 20 °C for a 1:2 CTAB:TRI mixture, significantly surpassing the performance of the individual inhibitors. Notably, the synergistic effect became even more pronounced at elevated temperatures, demonstrating the robustness of the combined system. Polarization studies identified both CTAB and TRI as mixed inhibitors, while adsorption analyses confirmed behavior consistent with the Langmuir isotherm, involving both physisorption and chemisorption mechanisms. Surface morphology characterization via Atomic Force Microscopy and Scanning Electron Microscopy validated the formation of a protective layer on the MS surface. Furthermore, computational modeling using the PM3 method provided deeper insights into the molecular interactions underpinning the enhanced inhibition performance. This work highlights the innovative potential of CTAB and TRI synergy, advancing corrosion inhibition strategies for industrial applications. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.