High-flux oil–water separation with superhydrophilicity and underwater superoleophobicity ZIF-67@Cu(OH)2 nanowire membrane

Abstract

High flux superwetting material has reverse wettability to oil or water phase, which plays an important part in oil–water separation and is one of the current research hotspots. Herein, we reported a ZIF-67@Cu(OH)2 nanowire array-coated metal mesh prepared using self-assembly and chemical oxidation method. These freshly prepared copper meshes with micro-/nanosecondary rough structure exhibit excellent underwater superoleophobicity and superhydrophilicity. Thus, the as-prepared mesh membrane has an excellent separation capability and can be used for oil–water separation. It shows extremely high efficiency oil–water separation function (99%), excellent cycling ability and high permeation flux (23,854 L m−2 h−1) in several typical oil–water separation processes. The mesh membrane also shows excellent underwater superoleophobicity in different pH values conditions. Besides, the as-prepared mesh membrane shows excellent durability and stability. Consequently, this work provides an economical and effective method for modification on metal substrate to prepare a underwater superoleophobicity/superhydrophilicity material to realize efficient separation of oil–water mixtures.