Corrosion protection of mild steel in acidic media using CBL: electrochemical and gravimetric insights at elevated and ambient temperatures

Abstract

Corrosion of mild steel in acidic environments poses a major challenge in industries such as descaling and petrochemical processing; in this regard, corrosion inhibitors play an important role in mitigating material degradation. The present work focuses on the utilization of cigarette butt litter (CBL) waste, an effective corrosion inhibitor for mild steel in acidic medium for extreme environment. CBL not only addresses waste management but also offers alternatives to traditional inhibitors. The research employed gravimetric analysis, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization techniques to evaluate the inhibition effects of the water extract of CBL on mild steel, which has the potential as a sustainable solution for corrosion prevention. It observed that the inhibition efficiency improved with the addition of CBL and maximum inhibition efficiency of 98.48% achieved at 15% HCl concentration. CBL exhibits the efficiency of 92.82% at higher temperature of 333 K which confirmed higher performance even at elevated temperature. Also, Langmuir adsorption isotherm (\({\Delta G}_{ads}^{0}\)) of − 10.71 kJ/mol confirming the physisorption mechanism shows the enhanced chemical bonding at the mild steel substrate that improves the corrosion resistance. The slight shift in \({E}_{corr}\) as compared to the blank acidic solution indicates that CBL functions as a mixed-type corrosion inhibitor that shows the effective reduction of both anodic and cathodic reactions, offering comprehensive protection against corrosion in acidic environments. Furthermore, the FESEM and AFM micrographs confirmed the formation of protective film barrier of CBL over the mild steel surface. The main chemical components were examined through a theoretical study, showing good alignment with the experimental data. The mechanism shows that nicotine in CBL adsorbs onto mild steel, forming a protective film that inhibits corrosion in acidic solutions by blocking corrosive species.