Graphitic-like carbon nitride improved thermal stability and photocatalytic antifouling performance of polyether sulfone membranes

The poor thermal tolerance of organic membrane and membrane fouling are two of the main obstacles for wider application of membrane process. Adding inorganic compounds which own fascinating chemical property and thermal stability as the additives may be an effective method to alleviate the problems. In this study, different amount of graphitic carbon nitride (g-C3N4) were introduced into polyether sulfone (PES) membranes by the phase-inversion method. The impacts of the g-C3N4 addition on the structure, thermal stability, filtration property and photocatalysis of g-C3N4/PES nano composite membranes were systematically studied. The results illustrated that the g-C3N4 well dispersed into PES matrix without obvious aggregation. The g-C3N4 introduction slightly improved the hydrophilicity of the nano composite membrane and did not sacrifice the separation property. The thermal stability of g-C3N4/PES nano composite membranes was examined in terms of thermogravimetric analyses (TGA) and water flux recovery ratio (FRR) after which were heated treatment at different temperature (50–80 °C) for different times (30–240 s). The results revealed that the thermal stability and the filtration performance of PES membrane were significantly improved by the incorporation of g-C3N4 nanosheets. Also the addition of g-C3N4 nanosheets could endow the nanocomposite membranes with photocatalytic antifouling property.