Abstract: Some embodiments include a method of preparing polymer nanofiber composites using a cross-linkable polymer precursor solvated with a solvent, and forming a nanofiber precursor by mixing with a metal-organic-framework (MOF) crystal material that includes a metal ion coupled to at least one multidentate ligand. Further, the method can include forming a plurality of nanofibers by electro-spinning the nanofiber precursor, where at least a portion of the nanofibers includes a dispersion of the first MOF crystal material. The method can include crosslinking the plurality of nanofibers by irradiating the plurality of nanofibers with UV light, IR light, visible light, gamma radiation, and/or electro-beam radiation. Further, the method can include applying a second MOF crystal material between the cross-linked nanofibers and the first MOF material.