High performance graphene-based composite membranes have attracted great attentions

however

graphene-based nanofiltration membranes usually exhibit low water flux in removing salt ions

which limits its application in water desalination. Novel reduced graphene oxide (rGO)/ultrathin carbon nitride (uCN) composite nanofiltration membrane was prepared by self-assembling rGO and nanoporous uCN nanosheets on polydopamine (PDA) modified polysulfone (PSF) support via vacuum filtration. Field emission scanning electron microscope (FESEM)

transmission electron microscope (TEM)

X-ray diffractometer (XRD)

Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy analysis (XPS) were applied to evaluate the changes in structure and morphology of membranes by introducing uCN. The effects of addition ratios of uCN

rGO content and operating pressure on the performance of composite membranes were also investigated. With 20 mg·L-1 uCN content in 100 mg·L-1 of rGO

the prepared rGO/uCN composite membrane not only maintained satisfied salt rejection rates (85.86% for Na2SO4

30.17% for NaCl)

but also possessed 2.15 times water permeance (88.50 L·m-2·h-1·MPa-1) that of pure rGO membrane.