Microwave-assisted Fast Preparation of Functionalized Carbon Dots: the impact of ionic liquid precursor on corrosion inhibition

In this study, functionalized carbon dots were synthesized in one step from L-histidine and imidazolyl ionic liquids using an ionic liquid-assisted microwave method as green corrosion inhibitors for steel in a 1 M HCl solution. Different ionic liquid anions (CF3COO- and HSO4-) were introduced in the preparation of the carbon dots, and their microstructures and surface properties were characterized. Notably, the corrosion inhibition efficiency of the prepared CDs (assisted by CF3COO-) reached 94.2% at 5 mg‧dm-3. The corrosion inhibition behavior of CDs on mild steel in 1 M HCl was investigated through DFT calculations. Our investigation revealed that the anions of the selected ionic liquids have a certain influence on the structure of the carbon dots, which correlates with the performance of the carbon dot corrosion inhibitor. Therefore, this study provides guidance for the preparation of functionalized carbon dot corrosion inhibitors using a one-step microwave method and the selection of ionic liquids (as solvents, modifiers, and mediums for microwave conversion).