Chemical Oxidation Synthesized High-yield Carbon Dots for Acid Corrosion Inhibition of Q235 Steel

In this work, high-yield carbon quantum dots (CQDs) are successfully synthesized by a simple chemical oxidation method using acetaldehyde as raw material. Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), thermogravimetry (TGA), and XPS are used to analyze the structural characteristics of CQDs. The results demonstrate that many oxygen-containing functional groups are on the surface of carbon nuclei. The inhibitive efficiency of electrochemical experiments and weight loss is 87.1 % and 95.3 %, respectively. SEM observes the surface morphology of the sample after 72 h corrosion with or without CQDs, and EDS analysis confirms that CQDs are effectively adsorbed on the surface of carbon steel. Furthermore, through calculation, the standard adsorption-free energy of CQDs is -25 kJ/mol, concluding that the adsorption process is a combination of physisorption and chemisorption. This work is helping to solve the corrosion problem of metal equipment in the acid process.

Automated summary

In this study, high-yield carbon quantum dots (CQDs) were synthesized using acetaldehyde as a raw material through a simple chemical oxidation method. The structural characteristics of CQDs were analyzed using FTIR, TEM, TGA, and XPS, revealing the presence of numerous oxygen-containing functional groups on the surface of carbon nuclei. Electrochemical experiments and weight loss measurements showed high inhibitive efficiency of 87.1% and 95.3%, respectively. SEM observations confirmed the adsorption of CQDs on the surface of carbon steel, and the adsorption process was determined to be a combination of physisorption and chemisorption based on calculations of the standard adsorption-free energy (-25 kJ/mol) of CQDs. This research contributes to addressing the corrosion problem of metal equipment in acid processes.