Epoxy polymers reinforced with phosphorus-doped carbon dots for enhanced corrosion protection of carbon steel in marine environments

Abstract

Fish skin, a major component of fish waste, has been utilized in this study for the facile synthesis of phosphorus-doped carbon dots (PCDs). The study aimed to synthesize and investigate the potential application of PCDs as an effective material against corrosion when reinforced in different epoxy polymers. The UV-visible and fluorescence spectroscopic characterization of PCD from fish skin confirmed the presence of multifluorophores and P doping, while transmission electron micrograph images revealed that the synthesized PCD had a diameter ranging from 6 to 8 nm. Fourier transform infrared spectrometer analysis showed the presence of a carbon skeleton with conjugated carbon double bonds, amines, -OH groups, aromatic rings, and phosphate groups. PCD reinforcement in three epoxy polymers and their coating over BIS 2062 carbon steel showed that PCD and epoxy polymers synergistically acted to improve the corrosion resistance of the coatings. An optimum concentration range of 0.01%–0.02% PCD was found to provide maximum corrosion resistance. PCD reinforcement has a potential impact on surface morphologies and electrochemical characteristics of epoxy coatings.