Superhydrophobic kaolinite modified graphene oxide-melamine sponge with excellent properties for oil-water separation

In this work, a facile and cost-effective method was reported to fabricate a novel, robust, and superhydrophobic kaolinite modified graphene oxide-melamine sponge (K-GOMS). The GO sheets were used to increase the roughness of the sponge smooth surface. The hydrophobic kaolinite adhered on GO sheets significantly enhanced the superhydrophobicity of the K-GOMS surface with a water contact angle of 152.3 degrees. Several organic solvents and oils were selected to test the adsorption performance of the obtained adsorbents. The results revealed that the superhydrophobic K-GOMS exhibited not only superior adsorption capacity for various organic solvents and oils, from 60 to 113 times of its own weight, but also outstanding recyclability with an adsorption capacity retention higher than 94% after 30 cycles of diesel oil adsorption, and excellent environmental tolerance in wide range of pH values and temperatures. Therefore, this study provides an effective way for constructing facile, low-cost, and large-scale production of superhydrophobic adsorbents for oil-water separation.