Evaluation of the inhibition behavior of carbon dots on carbon steel in HCl and NaCl solutions

An eco-friendly and effective corrosion inhibitor (N-CDs) was acquired by hydrothermal method in methacrylic acid and ethyl(methyl)amine precursors. Afterwards, the weight loss and electrochemistry measurement were chosen to appraise the corrosion inhibition behavior of as-prepared N-CDs for Q235 steel in Cl(-)contained solutions. The change rules of EIS and Tafel data displayed that the as-prepared N-CDs revealed a high-efficiency protection for steel in all test environments. Meanwhile, the inhibition efficiency of steel reached up to 93.93% (1 M HCl) and 88.96% (3.5 wt% NaC1) at 200 mg/L of N-CDs. Furthermore, the N-CDs could form the adsorption film on steel surface to avoid the strong attack of Cl. By analysis, the adsorption mechanism of as-prepared N-CDs on steel surface was physicochemical interaction, which strictly complied with the Langmuir adsorption model in both solutions. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.