A synergistic anti-corrosion system based on durable superhydrophobic F-SiO2/epoxy coatings and self-powered cathodic protection

Abstract

A sustainable, reliable and self-powered anti-corrosion method for metallic structures is key to improving the operation stability and service life of equipment. In this work, a series of durable superhydrophobic fluorinated silica (F-SiO₂)/epoxy resin (FE) coatings with good corrosion resistance were prepared via a simple spraying method, which were further used to fabricate a FE based triboelectric nanogenerator (FE-TENG). A synergistic anti-corrosion system for self-powered cathodic protection constructed using the superhydrophobic FE coating and a water wave-driven FE-TENG was then proposed. In a 3.5 wt% NaCl solution, the corrosion potential (E_corr) of an aluminum (Al) sheet protected by the FE-TENG self-powered cathodic protection was slightly decreased by 80 mV. However, when the Al sheet was coated with a FE superhydrophobic coating, the E_corr was significantly reduced by 460 mV under FE-TENG protection. Notably, the E_corr of 304 stainless steel protected by the synergistic anti-corrosion system was dramatically decreased by ∼745 mV. Furthermore, an application in marine corrosion protection was demonstrated by using a float-like spherical FE-TENG. This work demonstrates a cost-effective and large-scale strategy for preparing a superhydrophobic FE coating, using which a self-powered synergistic anti-corrosion system is built for effectively protecting metals from corrosion.