Study On The Preparation Of Carbon Dots Assisted By Ionic Liquid And Its Corrosion Inhibition Performance On Carbon Stee

Metal materials have been widely applied in industrial production and domestic installation due to their low cost and excellent physical properties,of which steel is the most basic building material,known as the"bones of industry".Meanwhile,the economic loss caused by metal corrosion is also huge.Corrosion inhibitor as an ease of use and inexpensive protective measure with superior corrosion inhibition effect,is widely used in the field of metal corrosion protection.At present,a large number of corrosion inhibitors have been applied in such field.In recent years,carbon dots（CDs）corrosion inhibitor,characteristic of low cost,rich in source and nontoxicity,has received wide attention from relevant scholars,which is expected to replace the traditional inorganic and organic corrosion inhibitors.However,issues such as poor dispersion and harsh preparation conditions in the preparation of carbon dots still exist,which greatly limit the application of carbon dots in metal protection.In this study,we hope to solve these problems by using green and environmentally friendly ionic liquids with excellent properties.A series of N,S-doped carbon dots were prepared by using green non-toxic ionic liquid 1-butyl-3-methylimidazolium bromide as the solvent and L-cysteine（L-cys）as the carbon source and by varying the preparation time of carbon dots.the TEM characterization results showed that the prepared carbon dots were well dispersed and the performance of carbon dots as corrosion inhibitors was evaluated by electrochemical tests.The carbon dot corrosion inhibitors with corrosion inhibition efficiencies of 93.2-97.0%were obtained in short reaction times（15 min,30 min,60min,120 min）.The best corrosion inhibition efficiency of up to 97%was obtained when the preparation time of carbon dots was 60 min.The corrosion inhibition mechanism of carbon dots was studied thoroughly by XPS,AFM,SEM and other characterization techniques,and a related adsorption model was proposed.Using the catalytic nature of the acidic ionic liquid 1-propylsulfonic acid-3-methylimidazole hydrogen sulfate for organic reactions,we were able to obtain carbon dots at lower temperatures（180°C,200°C,220°C）using L-cysteine as the carbon source.The structures of the prepared carbon dots were investigated by XPS,TG,IR and other characterization techniques.The highest graphitization of the prepared carbon dots was achieved when the reaction temperature was at 220°C.The electrochemical performance of 45#carbon steel in 0.5 M H₂SO₄ solution containing carbon dots was tested by electrochemical methods,and the results showed that the corrosion inhibition of 45#carbon steel by carbon dots reached 90.10-97.18%,and the best corrosion inhibition performance of 97.18%was prepared at 220°C.The ionic liquid-assisted preparation of carbon dots is expected to make carbon dots widely used in the field of metal corrosion protection.