Fabrication of hierarchically porous Cu/PVDF/CeO2 membranes via synergistic NIPS-spraying for robust oil-water separation.

High-efficiency oil-water separation membranes based on low-mesh copper mesh offer advantages in cost-effectiveness, scalability, and adaptability to complex separation scenarios. However, their inherently large pore size usually results in insufficient separation precision. In this work, the Cu/PVDF/CeO2 composite membrane is fabricated on the copper mesh substrate by combining the non-solvent induced phase separation method with spraying and immersion techniques. By adjusting the porogen content, the pore size of the composite membrane is effectively regulated, leading to enhanced separation efficiency. This strategy aims to simultaneously achieve superhydrophobicity and high-precision oil-water separation on low-mesh-number copper mesh substrates. The Cu/PVDF/CeO2 composite membrane achieves a maximum water contact angle of 158.7°, exhibiting superhydrophobicity. In oil-water separation tests, the membrane demonstrates a separation efficiency exceeding 98.5% for all tested oil-water mixtures. Optimal performance is observed in the separation of the immiscible mixture of dichloromethane and water, where the membrane achieves a separation efficiency of 99.83% alongside a high separation flux of 79138.4 L m-2·h-1. Additionally, the composite membrane exhibits excellent long-term stability and cycling stability. This study provides a feasible method for the preparation of high-efficiency oil-water separation composite membranes based on copper mesh substrates, with potential applications in industrial wastewater treatment and environmental remediation.