In situ modification of melamine sponge by MgAl-LDH with super-hydrophobicity and excellent harsh environment tolerance for high flux emulsion separation

Effective treatment of oily wastewater, particularly oil–water emulsions, has been a significant issue that is threatening human society. Developing a simple, efficient, and stable super-hydrophobic material is appealing for the application of oil–water separation. In this study, an in-situ growing approach was proposed to create a super-hydrophobic MgAl-LDH modified melamine sponge (MA-LDH@MS) with a contact angle of 163.2°. The surface roughness and physicochemical stability of MS were improved by MgAl-LDH microcrystals, resulting in outstanding environment tolerance against a variety of difficult circumstances such as strong acid and alkaline (pH = 1–14), high salinity (10–60 wt‰), UV exposure (254 nm, 15 days), and mechanical compression (50–200 cycles). Furthermore, the prepared super-hydrophobic MA-LDH@MS exhibited excellent oil adsorption capability (70.5–137.2 g·g−1) and high emulsion separation efficiency (more than 95%) with a throughput of 6.2 × 103 L m−2h−1. This work demonstrates a facile synthesis technique for producing stable super-hydrophobic monolithic materials with considerable potential for oil–water separation.