MOF Nanosheets-decorated electrospun nanofiber membrane with Ultra-high adsorption capacity for dye removal from aqueous solutions

Metal-organic frameworks (MOFs) such as zeolitic imidazolate framework (ZIF) have shown potential in removing various contaminants from water. However, the MOF materials, usually in powder form, suffer from easy aggregation and poor recyclability, limiting their practical applications in water treatments. Here, we have designed leaf-like MOF-decorated electrospun nanofiber membrane as adsorbent to address the problems. More specifically, two dimensional ZIF-L materials were decorated on electrospun polyacrylonitrile nanofibers (NF) using an in-situ growth method. The obtained ZIF-L/NF nanocomposite can efficiently adsorb toxic malachite green and reach a high adsorption capacity of 5103 mg g−1, attributed to the π-π stacking interactions between the ZIF-L and the dyes. The adsorption process conforms to pseudo-second-order kinetics and Langmuir isotherm model. From thermodynamic analysis, it was found that the adsorption was spontaneous and endothermic. Moreover, the ZIF-L/NF nanocomposite also exhibits excellent recyclability in the adsorption–desorption test.