Hierarchically Engineered Triple‐Defensive Antifouling Coating with Well‐Regulated Structure for Enhanced Wastewater Treatment

Abstract Intergrading traditional hydrophilic coating with tailored functionalities is critical to enhance its antifouling capabilities. However, designing robust functional antifouling coatings with well‐regulated structures to boost its antifouling performance remains a significant challenge. By mimicking the unique structure of shark skin with super‐hydrophilic “denticle layer” and low‐surface‐energy “mucus layer”, for the first time, a facile strategy is presented to hierarchically engineer a triple‐defensive antifouling coating, which consists of a hydrophilic mineralized catalytic nanoparticle (NP) layer, overlaid with hydrophobic perfluoro‐silane domains (F@NPs), synergistically optimizing its fouling resistance, fouling release, and fouling degradation properties. Force measurements and dynamic simulations demonstrate that molecular‐scale incorporation of perfluoroalkyl chains on coating surface significantly reduces foulant adhesion while preserving hydrophilicity, thereby effectively preventing over 98% of oil contamination, protein adsorption, and bio‐fluid fouling. Its antifouling properties are further enhanced by the unique catalytic self‐cleaning ability, enabling rapid degradation of adsorbed organic compounds and bacteria contact killing. Moreover, F@NPs‐coated membrane achieves a water flux over 4200 L m⁻² h⁻¹ bar⁻¹ with flux recovery ratio exceeding 95% for separation of oil‐in‐water emulsions containing bio‐foulants. This study presents an innovative strategy for fabricating robust functional coating with superior antifouling performance for environmental engineering applications.