Paper
Abstract The chemical modification of carbon fiber surface often uses toxic reagents and harsh reaction conditions, while the preparation process of metal‐phenol networks (MPNs) is simple, rapid, non‐toxic and harmless, which provides a direction for alleviating environmental problems. In this study, tannic acid (TA) was coordinated with Fe 3+ to form MPNs, which was coated on the surface of carbon fibers through π‐π interaction. The results indicated that oxygen functionalities on the surface of the MPN coating can facilitate better adhesion between the carbon fiber and the epoxy resin, when the molar ratio of TA to Fe 3+ is 1:3 and the pH is 4, the interlaminar shear strength (ILSS) performance of the composite material reaches its optimal level. In addition, a green and non‐destructive method is provided for the surface modification of carbon fiber, which can effectively optimize the interfacial properties of carbon fiber reinforced polymer (CFRP) composites.