Flow-through catalytic nanofiber membrane assembly of hierarchically porous structure with Ag nanoparticles immobilized for enhanced catalysis

A hierarchically porous flow-through catalytic nanofiber membrane immobilized with Ag nanoparticles (Ag/HP-FCNM) has been developed by combining electrospinning and sacrificial template. The characterization results of Ag/HP-FCNM imply that mesopores with an average size of 50 nm are successfully fabricated on Polyacrylonitrile (PAN) nanofibers, and 6 nm of Ag nanoparticles are immobilized in the mesopores, effectively preventing the aggregation of Ag nanoparticles and increasing the surface area. The HP-FCNM with Ag nanoparticles content of 35.02% has a permeance of 18680 L·m −2 ·h −1 ·bar −1 can enhance the contact between catalyst and reactant. During the process of p -Nitrophenol ( p -NP) reduction by Ag/HP-FCNM under the flow-through mode, the apparent reaction rate constant ( K app ) of 272.45 min −1 , treatment capability of 200.34 mmol·m −2 ·h −1 and specific treatment capability of 14.27 mmol·g −1 ·h −1 can be achieved. Furthermore, good applicability of the Ag/HP-FCNM is also demonstrated with excellent conversions (both above 99%) when treating o -Nitrophenol ( o -NP) and Rhodamine B (RhB) at a concentration of 0.25 mM and a membrane flux of 192 L·m −2· h −1 . Good stability can be still performed after 160 min of continuous use, which implies the prospect of the Ag/HP-FCNM.