Biomimetic leaf wax layer self-healing superhydrophobic MOF sponge with dual applications: High-capacity oil adsorption and efficient cationic dye elimination

In this work, a multifunctional biomimetic self-healing superhydrophobic MOF sponge (HDTMS@UiO-66-NH 2 @PDA@MS) was prepared for efficient oil-water separation and cationic dye wastewater removal. A PDA layer was formed on the surface of the sponge by DA oxidation and self-polymerization, and UiO-66-NH 2 was loaded onto the melamine sponge. To further enhance the hydrophobic properties of the MOF sponge, cetyltrimethoxysilane (HDTMS) is hydrolyzed and condensed to form a non-toxic layer of low surface energy polysiloxane adhesive on the surface of the sponge. The prepared modified sponge exhibited excellent superhydrophobicity (water contact angle of 156.2°), high oil adsorption capacity (73.2–164.7 g/g), and cationic dye removal rate (more than 95 %). Inspired by the self-heal mechanism of the wax layer on plant leaves, the modified sponge and can achieve rapid self-heal at 250 °C after simulated oxidative damage. In addition, the synergistic effects of excellent oil-water separation efficiency, reusability, environmental stability, self-cleaning capabilities make HDTMS@UiO-66-NH 2 @PDA@MS a promising candidate for marine oil spill remediation and oily wastewater treatment.