Encrusting MOF nanoparticles onto nanofibers via spray-initiated synthesis to boost the filtration performances of nanofiber membranes

Metal-organic frameworks (MOFs) are currently one of the most attractive porous materials. Integrating MOFs into an organic polymer matrix is considered a promising approach for controlling air pollutants. Especially, the nanoscale miniaturization of MOFs is promising to serve as membranes for efficient air quality control. Here, we proposed the use of spray-initiation as a facile and rapid methodology to assemble homogeneous growth of nanoMOFs on the electrospun fibers, yielding the composite fiber with diameters smaller than 300 nm. The developed ZIF-8-encrusted nanofiber membrane achieved superior filtration performance. Compared with the filter without MOF growth, the MOF-encrusted nanofiber filter achieved enhanced filtration efficiency and almost no change in pressure drop. For the most penetrating particles, the ZIF-8-encrusted nanofiber filter can even reach a 10% increment. This work shows that introducing the MOF nanoparticles onto the nanofibers with homogenous distribution can significantly improve the capacity of the filters in controlling submicron particles, and provide an important reference for the rational design of structures of composite materials.