Bioinspired mortise-tenon interlocking HKUST-1/CuOH micro-nano architectures on stainless steel mesh for oil-water separation membranes

The degradation of separation performance caused by the high abrasion of the continuous separation process puts forward more requirements for the adaptability and durability of the oil-water separation membranes. Herein, inspired by the mortise and tenon (MT) structures of ancient Chinese wooden frame buildings, a superhydrophilic and underwater superoleophobic stainless steel mesh (SSM) membrane with HKUST-1-copper hydroxide (CuOH) interlocking micro-nanostructures (HKUST-1/CuOH) was prepared via electrodeposition and hydrothermal growth techniques. The homogeneous growth of HKUST-1 and CuOH with superhydrophilicity and MT structures provides ultral wettability and durability for the HKUST-1/SSM/CuOH membrane. The optimal HKUST-1/SSM/CuOH membrane exhibited a water contact angle of 0° and an underwater oil contact angle of 156°. The flower-like microstructures improve acid and alkali tolerance, organic solvent tolerance, NaCl solution tolerance, thermal resistance, and UV aging performances. In addition, the HKUST-1 and CuOH coatings showed superior and durable antibacterial performance of the HKUST-1/SSM/CuOH membrane. This membrane with an MT structure demonstrated excellent reusability, showing a water flux of 23818 L·m –2 ·h –1 and UWOCA of 152.09° after 20 cycles. The proposed method is a promising candidate for unrelenting superhydrophobicity and high permeability in oily water treatment.