Improvement of carbon dots corrosion inhibition by ionic liquid modification: experimental and computational investigations

Chemical modification is effective in improving the corrosion inhibition efficiency of carbon dots (CDs) on steel. Here, the imidazolium ionic liquids (IL) modified-CDs (IL-CDs) are synthesized and proved to be mixed-type corrosion inhibitors. The IL increases the pyrrole N content and facilitates the formation of a denser inhibitor film. Molecular simulations confirm that the IL reduces the π-π interaction between CDs, endowing IL-CDs with higher water solubility and better corrosion inhibition effect than CDs. The lower orbital energy gap and larger positive electrostatic potential distribution enable the inhibition efficiency of IL-CDs of 97.11% in 1 M HCl, much superior to CDs (90.80%).