Novel high-performance and long-life anti-corrosion coating with rust conversion and self-healing characteristics based on waste biomass derived carbon nanosheets

Fabrication of coating system with high-performance and long-life anti-corrosion performance is an important way of prolonging service life and reduces the waste of metal equipment. Herein, one smart coating with rust conversion and self-healing characteristics was prepared though the addition of tannic acid (TA)-grafted cornstalks derived carbon nanosheets (CNS) and 8-hydroxyquinoline (8-HQ)-loaded mesoporous silica (MS) into the coating. Thermogravimetric analysis results indicated that the grafting/loading rates for TA and 8-HQ were 17.5% and 27.3%, respectively. Pull-out test results reflected that the value of dry adhesion of the smart coating at the steel/coating interface was two times higher than that of the pure coating. Electrochemical impedance spectroscopy results reflected that the anti-corrosion performance and service life of the coating were evidently improved, and the coating exhibited self-repairing property. /Z/f=0.01Hz of smart coating was still 1.8 × 107 Ω cm2 after 80 days immersion. The high-performance and long-life of the coating were attributed to the sheet structure of CNS, formation of TA-Fe layer at steel/coating interface as well as chelate products between 8-HQ and corrosion products. It is expected that the prepared smart coating could find wide application due to the simplification the operations and improvement the service life of traditional coating.