Nitrogen/Sulfur Co‐Doped Carbon Dots for Enhancing Anti‐Corrosion Performance of Mg Alloy in NaCl Solution

Abstract To reduce the corrosion of Mg alloy, an environment‐friendly Nitrogen/Sulfur co‐doped carbon dots (N/S‐CDs) was prepared using thiourea and 4‐amino salicylic acid as precursors. The corrosion inhibition behavior of N/S‐CDs for Mg alloy in 3.5 wt.% NaCl solution was systematically investigated by electrochemical measurements. The results shown that N/S‐CDs could suppress the corrosion of Mg alloy and the inhibition efficiency reached 86.6 % at 50 mg L −1 . The low energy gap (0.156 eV) and high dipole moment (11.19 D) indicated that N/S‐CDs has a strong chemical adsorption on Mg by quantum chemistry calculation. Meanwhile, the adsorption process is conformed to the Langmuir adsorption isotherm, belonging to the physical/chemical mixed adsorption.