Graphitic carbon nitride (g-C3N4) nanosheets functionalized composite membrane with self-cleaning and antibacterial performance.

Membrane fouling significantly impedes membrane performance and thus short lifespan of the membrane. Membranes that functionalized with photocatalytic activity are deemed as an effective and novel approach to settle membrane fouling. The membranes with self-cleaning and antibacterial performance were fabricated via facilely filtering g-C3N4 nanosheets onto polyacrylonitrile (PAN) porous substrates. The g-C3N4 nanosheets were exfoliated by acid etching and ultrasound treatment, and the exfoliated nanosheets was verified by Fourier transform infrared spectra, Atomic force microscopy and X-ray diffraction. The g-C3N4 nanosheets functionalized composite membranes have a water permeability of 11.70 L m-2 h-1 bar-1 and a good antibacterial activity. In addition, the membranes could be restored their original permeability and their surfaces were close to initial color even after three cycles rejecting dyes and post treatment under irradiation with visible light. Besides, the degradable and antimicrobial mechanisms of the membranes were investigated respectively. These g-C3N4 nanosheets composite membranes with self-cleaning and antimicrobial properties have a potential feasibility in water treatment, and provide an alternative method for fabricating self-cleaning membranes.