Improved corrosion resistant performance of mild steel under acid environment by novel carbon dots as green corrosion inhibitor

A novel eco-friendly, water soluble and effective corrosion inhibitor N, S-CDs was synthesized by hydrothermal method. The characterization of N, S-CDs was carried out by Fourier transformation infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis) spectroscopy, photoluminescence (PL), Raman spectroscopy, Xray photo electron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). The inhibitive effect of N, S-CDs on mild steel (MS) corrosion was evaluated by weight loss analysis, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods in 15% HCl solution. As per potentiodynamic polarization studies, studied inhibitor acts as mixed type inhibitor. Investigated N, S-CDs exhibited 98.64% of inhibition efficiency at 200 mg / L concentration and 303 K temperature. Investigated N, S-CDs corrosion inhibitor shows better corrosion inhibition efficiency as compared to the most of the similar type of corrosion inhibitors already reported in literature. The adsorption of N, S-CDs on MS surface followed Langmuir adsorption isotherm. The surface morphology of MS specimens was studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurement.

Automated summary

A novel eco-friendly, water-soluble and effective corrosion inhibitor N, S-CDs was synthesized and characterized using various techniques. The inhibitor exhibited significant inhibition efficiency on mild steel corrosion in 15% HCl solution and followed Langmuir adsorption isotherm on MS surface.