Corrosion inhibition of high-nitrogen-doped CDs for copper in 3wt% NaCl solution

Carbon dots (CDs) can be designed as an effective assembly unit to construct the intelligent corrosion inhibition system. Compared to purified CDs, the doped CDs have more advantageous anti-corrosion performance. However, the reported nitrogen-doped CDs usually have a low N/C atomic ratio. The increase of the N/C ratio has an important significance in improving the properties of nitrogen-doped CDs for corrosion protection. The high-nitrogen-doped CDs (N-doped CDs) are prepared from melamine and fructose via solvothermal treatment. The corrosion inhibition effect of the N-doped CDs for copper in 3wt% NaCl solution is studied by electrochemical measurements, surface characterizations and fluorescence spectrum analyzer. It demonstrates that the N-doped CDs can protect the copper in 3wt% NaCl solution effectively. The nitrogen content of the N-doped CDs is improved to 23.95%.The optimal inhibition efficiencies reach 96.1% at 200 mg⋅L−1 of the N-doped CDs. The N-doped CDs can form a compact protective film on copper surface via adsorption and chelation with cupric ions.