High-Efficiency Preparation of Reduced Graphene Oxide by a Two-Step Reduction Method and Its Synergistic Enhancement of Thermally Conductive and Anticorrosive Performance for Epoxy Coatings

Herein, a simple and high-efficiency two-step reduction method is developed to prepare graphene. Graphite oxide is reduced by Fe powder and microwave thermal reduction. The two-step microwave-assisted reduction method greatly shortens the preparation time of graphene. The obtained microwave-reduced graphene oxide (MrGO) possesses obvious graphene characteristics and high C/O atomic ratio. The thermal conductivity of epoxy coating incorporating 5 wt % MrGO-6 increases to 0.66 W/(m·K), an almost 267% enhancement compared with pure epoxy (0.18 W/(m·K)). Importantly, the coating resistance of epoxy/MrGO-6 is 2–3 times higher than that of epoxy after being immersed in 3.5 wt % NaCl aqueous solution. The MrGO/polymer composites have potential application prospects in the field of corrosion protection for heat exchange equipment due to its high thermal conductivity, excellent anticorrosion performance, and simple preparation method.