To address the limitations of conventional epoxy coatings—limited physical barrier function and lack of active protection in harsh marine environments—this study proposes a novel design strategy for a two‑dimensional/two‑dimensional (2D/2D) heterostructured nano‑filler. ZIF‑L crystals were directly grown on the surface of graphitic carbon nitride (g‑C₃N₄) via an in situ growth method, constructing a ZIF‑L@g‑C₃N₄ hybrid material that integrates efficient physical barrier properties with intelligent responsive functionality. The material not only extends the diffusion path of corrosive media through the layered structure of g‑C₃N₄, but also utilizes the controlled decomposition of ZIF‑L under corrosive micro‑environments to release Zn²⁺ and 2‑methylimidazole, achieving active self‑healing and chemical protection at coating defects. Systematic electrochemical and mechanical tests revealed that the epoxy coating incorporated with ZIF‑L@g‑C₃N₄ maintained a low‑frequency impedance modulus of 10⁸ Ω·cm² after 40 days of immersion in 3.5% NaCl solution, significantly outperforming pure epoxy and single‑component modified coatings. Moreover, the coating substrate adhesion strength increased to 3.723 MPa, demonstrating excellent interfacial bonding. This work not only develops a high‑performance anti‑corrosion coating with a synergistic “passive barrier‑active repair” dual mechanism, but also provides a new structural design strategy and technical pathway for designing next‑generation intelligent anti‑corrosion composite materials. • Combined 2D ZIF with g-C 3 N 4 to enhance epoxy resin's anti-corrosion performance. • 28-day immersion kept coating's low-frequency impedance near 10 8 Ω·cm 2 . • ZIF-L@g-C 3 N 4 boosts coating adhesion to 3.723 MPa, surpassing pure epoxy.
Duan et al. (Sun,) studied this question.