High-Flux MXene Quantum Dot/Graphene Oxide Composite Nanofiltration Membranes: Preparation and Water Purification Performance

Efficient wastewater treatment requires nanofiltration membranes with both high water flux and strong dye rejection. Although graphene oxide (GO) membranes offer excellent molecular sieving capability, their narrow interlayer spacing severely restricts water transport. MXene quantum dots (MQDs), possessing abundant surface terminations, high hydrophilicity, and structural tunability, offer an effective strategy to tailor interlayer channels and enhance transport. Here, a GO/Ti₃C₂ QDs composite membrane is fabricated, where the QDs are uniformly intercalated between GO lamellae, preventing restacking, enlarging the interlayer spacing, and imparting favorable physicochemical characteristics. The GO/Ti₃C₂ QDs membrane displayed excellent hydrophilicity and outstanding water purification performance. Compared with pristine GO membranes, the GO/Ti₃C₂ QDs composite (mass ratio of 1:2) exhibited a 121% increase in water flux, reaching 64 L·m^-2·h^-1·bar^-1, while maintaining high dye rejection. These GO/Ti₃C₂ QDs membranes demonstrate high permeability, efficient dye removal, and promising potential for practical water purification applications.