Corrosion inhibition of tetrabutylphosphonium benzotriazolate on carbon steel in acidic medium

The inhibition effect of tetrabutylphosphonium benzotriazolate (TBPB) on carbon steel in a 1 mol·L -1 HCl solution was investigated using a combination of analytical techniques, including polarization curve, electrochemical impedance spectroscopy, scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The study revealed that TBPB acts as a mixed corrosion inhibitor for carbon steel in acidic conditions. The efficiency of corrosion inhibition was observed to increase gradually with rising TBPB concentrations, reaching a maximum of 92% at a concentration of 10 mmol·L -1 . This enhancement in corrosion inhibition efficiency is attributed to the adsorption of TBPB on the metal surface, effectively isolating it from the corrosive medium and thereby preventing corrosion reactions. Importantly, this mechanism aligns well with the Langmuir isothermal adsorption model.