Experimental and theoretical calculations of fluorinated few-layer graphene/epoxy composite coatings for anticorrosion applications

Abstract

Corrosion protection technology plays a crucial role in preserving infrastructure, ensuring safety, reliability and promoting long-term sustainability. In this study, we combined experiments and density functional theory (DFT) to investigate the mechanism of corrosion for fluorine-doped few-layer graphene (F-FLG). We introduced a facile approach that combines environmentally friendly jet cavitation with hydrothermal processes to synthesize hydrophobic and anti-corrosive F-FLG from graphite (G). By coating F-FLG/epoxy composite film (F-FLG/EP) on the surface of cold-rolled steel (CRS), we found that the addition of F dopant enhanced the hydrophobicity of the F-FLG/EP coating from 78.89° to 106.3°. Notably, the corrosion rate of the F-FLG/EP coating is 8.279 × 10−3 μmpy, which exhibits four orders of magnitude lower than that of the CRS substrate. The DFT calculations indicate an increased band gap for F-FLG. Moreover, the energy barrier for the oxygen diffusion through F-FLG is larger than that for FLG, indicating improved oxygen resistance for F-FLG. These results indicate the high efficiency and potential of F-FLG as a highly promising agent for preventing corrosion in various commercial applications.