Amphiphilic carbon dots as high-efficiency corrosion inhibitor for N80 steel in HCl solution: Performance and mechanism investigation

Three amphiphilic carbon dots (CDs, C 6 -CDs, C 8 -CDs, and C 12 -CDs) were synthesized and first adopted as a corrosion inhibitor for mild steel. The inhibition behavior of amphiphilic CDs for N80 steel in hydrochloric acid solution was studied via weight loss tests, surface characterization , and electrochemical measurements. Results confirmed that they could protect N80 steel effectively; the longer the carbon chain was, the better the inhibition effect was. Specifically, the inhibition efficiency of C 12 -CDs reached 92.9 % at 150 mg/L. Moreover, due to the fluorescence characteristics of CDs, the changes in adsorption film during corrosion could be directly observed under UV light . A dense adsorption film was formed through the electrostatic interaction with CDs and the metal surface . Long carbon chains formed a hydrophobic layer on the surface of N80 to isolate the corrosive medium.