3D-Printed Membranes for Water and Wastewater Treatment: Fabrication Strategies, Performance, and Future Perspectives

Three-dimensional (3D) printing has emerged as an alternative fabrication approach for membrane development, offering increased flexibility in membrane geometry, architecture, and material integration. Conventional membrane fabrication methods enable large-scale production but suffer from limited tunability of internal architecture, constraints on material combinations, and challenges in reproducibility. In contrast, 3D printing enables precise layer-by-layer construction, customizable pore morphologies, and the incorporation of functional fillers, thereby expanding the design space for high-performance membranes. Polymeric membranes produced by fused deposition modeling, direct ink writing, digital light processing, and electrohydrodynamic techniques have demonstrated enhanced permeability and shape-defined porosity. Hybrid membranes integrating polymers with nanoparticles, ceramics, and catalytic materials exhibit improved mechanical stability, antifouling behavior, and multifunctionality. Ceramic membranes fabricated through 3D printing show advances in structural precision, high-temperature stability, and the integration of catalytic and photocatalytic functionalities for the removal of micropollutants, pharmaceuticals, and oil-in-water emulsions. Despite rapid progress, challenges remain, including the optimization of printing inks and rheology, multi-material co-printing, scale-up, and long-term fouling resistance. This review highlights opportunities for future development, particularly in hybrid catalytic systems, bio-derived raw materials, and digitally designed architectures. Overall, 3D printing represents a rapidly evolving fabrication approach that provides new opportunities for controlling membrane architecture and integrating functional materials for water treatment applications.