Polyethersulfone ultrafiltration membranes incorporated with CeO₂/GO nanocomposite for enhanced fouling resistance and dye separation

The hydrophilic CeO₂/GO nanocomposite was successfully synthesized and characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) methods. The SEM images of the nanocomposite confirmed meaningful decrease in the diameter of the CeO₂ nanoparticles from 90 to about 30–40 nm after loading on the GO nanosheets. The as-synthesized nanocomposite was incorporated by various contents into the matrix of the polyethersulfone (PES) membranes. The changes in the morphology of the blended membranes with introduction of the nanocomposite were analyzed using SEM and atomic force microscopy (AFM) techniques. All the CeO₂/GO-modified PES membranes showed higher hydrophilicity, porosity and pure water permeation compared with unmodified one. The pure water flux of the nanocomposite membrane containing 0.2 wt% of the nanocomposite was obtained as 249 L m⁻² h⁻¹, which was 152 L m⁻² h⁻¹ in the pure PES membrane. The results proved that fouling resistance of the nanocomposite membranes was intensified and increased from 39% for bare PES membrane to 69% for the membrane modified with 0.1 wt% of CeO₂/GO nanocomposite. The aqueous solution of Reactive Red 195 (R195), Reactive Red 43 (R43), and Yellow 105 (Y105) organic dyes were applied to evaluate the separation performance of the membranes. The results revealed that membrane modified with 0.5 wt% of CeO₂/GO exhibited the removal efficiency of 88%, 93% and 98% for R195, R43 and Y105, respectively. Furthermore, the membranes modified with CeO₂/GO showed better dye retention performance compared with membranes modified with CeO₂ and GO alone.