MOFs bound to melamine sponge for dye removal

In this study, metal–organic framework (MOF)-functionalized sponge columns were prepared using a simple approach by embedding melamine sponge in a homogeneous MOF solution and first applied in the removal of methyl orange dye from water samples. Various MOF materials (MIL-101(Cr), MIL-101(Fe), ZIF-8(Zn), HKUST-1(Cu), and MIL-68(Al)) with different structures were synthesized and used as coating materials for a blank sponge. This method not only can be used for a wide variety of MOF materials, but also can retain their unique properties. The results show that the sponge as an adsorbed base material can effectively simplify the separation procedures of adsorption. Under the optimal conditions, the prepared MOF/PVDF-sponge column had an excellent adsorption capacity (229.4 mg g −1 ) toward methyl orange and reached the equilibrium within 1 h. With simple one-step infiltration, excellent adsorption properties and simple operation, the MOF/PVDF-sponge column presents a promising commercial value. Moreover, this study provides a new approach for exploring functional porous sponges for adsorption of dyes from environmental water samples.