Hierarchical superhydrophobic coating with self-warning and self-healing function for enhanced corrosion resistance in H2S environments

Developing a multifunctional coating that combines self-warning, self-healing, and robust corrosion resistance remains a formidable challenge in metal protection. In this work, a hierarchical superhydrophobic composite coating is engineered to incorporate self-warning, self-healing, and H 2 S-digestion capabilities, which significantly enhanced its overall anti-corrosion performance in both simulated seawater and H 2 S corrosive environments. In H 2 S environments, the hierarchical superhydrophobic composite coating neutralizes the corrosive medium (H 2 S) through a two-pronged strategy. The Ce(IV)-MOF in the hydrophobic top layer actively oxidizes S 2- . Concurrently, H + degrade the ZrP@Tannic acid-(ε-poly- L -lysine) (ZrP@TA-PLL) in the underlying anti-corrosion layer, prompting the release of corrosion inhibitors/corrosion probes to establish a dual-function film capable of both detecting corrosion and repairing the substrate. After 90 days of immersion in 3.5 wt% NaCl solution and H 2 S environments respectively, the corrosion resistance of the hierarchical superhydrophobic composite coating improved by approximately 1.2 times and 6.86 times compared to the 5 wt% ZrP@TA-PLL/EP coating. This novel design not only holds significant potential for advancing the field of smart self-warning and self-healing anti-corrosion coating but also provides a high-performance solution specifically for surface protection against H 2 S corrosion.