Preparation Of Amino Carbon Dots And Their Corrosion Inhibition Performanc

The addition of corrosion inhibitors in corrosive media is one of the important means to inhibit metal corrosion,and the development of new green and efficient corrosion inhibitors is the current research hotspot for corrosion inhibitors.Carbon dots(CDs)have the potential to become green and efficient corrosion inhibitors,and the introduction of heteroatomic groups such as amino groups can further improve their corrosion inhibition performance,while the current law of the effect of precursor substituent content/type and CDs surface grafting on the corrosion inhibition performance of CDs is not clear.In this study,a series of amino CDs were designed and prepared by controlling the precursor substituent content,precursor substituent type and chemical modification of CDs.The corrosion inhibition performance of the prepared amino CDs on Q235 steel in 1 M hydrochloric acid medium was investigated,and the variation of the corrosion inhibition efficiency of CDs with structural composition was summarized.The main work includes:(1)Effect of amino content of precursors on the corrosion inhibition properties of the prepared CDs.Three amino CDs(N1-CDs,N2-CDs and N3-CDs)were designed and prepared by the solvent thermal method by controlling the amino content in the precursors(aniline,p-phenylenediamine and benzenetetetramine as precursors,respectively).Their morphology and structural composition were characterized by TEM,XPS,and FTIR.The corrosion inhibition efficiency of the prepared amino CDs on Q235 steel in 1 M hydrochloric acid medium was analyzed by electrochemical impedance spectroscopy,Tafel polarization curves and corrosion surface morphology(SEM and AFM)tests,and the corrosion inhibition efficiencies(concentration of 100 mg/L)were N1-CDs(93.5%),N2-CDs(91.4%)and N3-CDs(90.1%),respectively.This indicates that the precursor amino content has a small effect on the prepared amino CDs in terms of corrosion inhibition performance.(2)The effect of different substituents in the precursors on the corrosion inhibition properties of the prepared amino CDs was investigated.The Br-CDs,S-CDs and N2-CDs were designed and prepared by the solvothermal method with different substituents in the precursors,and their morphology and structure were characterized by TEM,XPS and FTIR.The corrosion inhibition performance tests showed that the introduction of both Br and S elements helped to enhance the corrosion inhibition performance of the amino CDs,with the corrosion inhibition efficiency of Br-CDs(94.4%),S-CDs(94.1%)and N2-CDs(91.4%)at a concentration of 100 mg/L,respectively.(3)Effect of surface modification of amino CDs on corrosion inhibition properties.The quaternized BS-CDs were prepared by grafting dodecyl betaine onto the surface of N3-CDs by amide reaction,and their morphology and structure were characterized by TEM,XPS,and FTIR.The corrosion inhibition performance tests showed that the corrosion inhibition efficiency of the quaternized BS-CDs was increased by about 3% compared with that before the modification.