Solvent-Exfoliated 2D WS₂/Polyethersulfone Antifouling Mixed Matrix Ultrafiltration Membrane for Water Treatment

Separation technology using membranes is an effective choice for water treatment, but fouling is a significant problem for membrane applications. Recently, transition metal dichalcogenide nanosheets have been promising for water treatment owing to their good antifouling properties compared to other nanosheets such as graphene oxide. However, using scalable exfoliation methods for membrane synthesis is still a great challenge. Among the various methods adopted to exfoliate nanosheets from the bulk, solvent exfoliation is eliciting increased interest because of its simplicity and flexibility. Herein, we first reported the preparation of solvent-exfoliated WS2 nanosheets for achieving polyethersulfone with improved performance as a modified membrane. The effects of WS2 nanosheets on the morphology and separation efficiency of the prepared membranes were determined in terms of pure water permeance and solute rejection. The results indicated that the water permeance increased from 200 to 360 L/m2 h bar with the solute rejection rate increasing from 89 to 98% for bovine serum albumin (BSA) and 87–98% for humic acid at a pH of 10 after the blending of WS2 nanosheets. The membrane long-term fouling resistance for BSA filtration showed the splendid antifouling property of the modified membrane. The mechanism for achieving a high rejection rate with a high flux for mixed matrix membranes was due to nanosheet-induced surface chemistry enhancement. Overall, our findings indicated the potential of the water treatment applications of WS2/PES mixed matrix membranes through the introduction of transition metal dichalcogenide nanosheets.