Polyacrylonitrile nanofiber membranes incorporated with large reduced graphene oxide content in situ

This work demonstrates an effective strategy for preparing electrospun composite membranes consisting of polyacrylonitrile (PAN) nanofibers and a large amount of graphene oxide (GO) and reduced graphene oxide (rGO). Simple surface modification of GO with a cationic surfactant reliably results in the preparation of composite nanofibers as a function of GO content up to 30 wt%, which are subsequently transformed into membrane-type sheets via heat and pressure treatments. In addition, an in situ hydrazine treatment readily converts the integrated GO into rGO, which is confirmed by water contact angles, Raman, XRD, and infrared thermography. These series of composite membranes are then employed in the removal of methylene blue dye with and without solar-simulated light irradiation. The PAN–GO composite membranes possessing various oxygen-containing functional groups initially display higher decontamination capability of the dyes than PAN–rGO. Both composite membranes notably improve the removal of the dyes to over 90% in 3 h under the light irradiation where the degree of removal efficiency for the PAN–rGO composite membrane is detectably increased due to its enhanced photothermal heating property. Although integrating GO derivatives into polymer nanofibers is a challenging task due to their limited dispersity and miscibility, our developed approach readily results in the systematic loading of GO and rGO at a high-level content into PAN nanofiber membranes, allowing us to realize their general properties including photothermal heating properties for various applications.