Intelligent multi-functional h-BN/ZIF-8 nanocontainers for high-performance anti-corrosion coatings

2D nanocontainers are prepared with barrier, corrosion inhibition and monitoring. • BZ-P/EP coating shows higher .|Z| f = 0.01 Hz of 4.1 × 10 10  Ω cm 2 after 60 days immersion. • PH-responsive ZIF-8 enables the rapid release of Phen under acidic conditions. • Visual corrosion warning is achieved via Fe 2+ –Phen coordination. To overcome the limitations of conventional anticorrosion coatings, which typically exhibit single functionality and lack early-stage corrosion warning capability, this study presents the design and fabrication of a two-dimensional intelligent nanocontainer system. Specifically, a pH-responsive zeolitic imidazolate framework (ZIF-8) was grown in situ on hexagonal boron nitride (h-BN) nanosheets, and subsequently loaded with 1,10-phenanthroline (Phen), enabling the integration of physical barrier protection, active corrosion inhibition, and visual corrosion monitoring. UV–vis absorption spectra and electrochemical impedance spectroscopy (EIS) results demonstrate that the BZ-P nanocontainers not only provide effective corrosion inhibition but also exhibit rapid, pH-triggered release of Phen in mildly acidic conditions. After incorporation into an epoxy matrix, the resulting BZ-P/EP composite coating exhibits a high low-frequency impedance modulus (|Z| f = 0.01 Hz ) of 4.1 × 10 10  Ω cm 2 after 60 days of immersion in 3.5 wt% NaCl solution, which is approximately 2270 times higher than that of the neat epoxy coating. This improvement is accompanied by a significant reduction in oxygen content on the underlying steel surface (from 19.56 wt% to 0.62 wt%), indicating markedly suppressed corrosion. Under damaged coating conditions, the BZ-P/EP system maintains effective corrosion protection, as evidenced by a relatively high impedance modulus and low local admittance. This enhanced performance can be attributed to the synergistic effects of BN and ZIF-8, which combines structural barrier reinforcement with active corrosion inhibition. Furthermore, the released Phen molecules at damaged sites coordinate with Fe 2+ ions to form a red complex, enabling rapid and intuitive visual detection of corrosion initiation. This work provides a novel strategy for developing intelligent coating systems that integrate corrosion protection, active corrosion inhibition, and real-time monitoring, offering significant potential for applications in harsh service environments.