Hierarchically-structured and bifunctional Cu-MOF nanowire-modified copper meshes for oil-water separation and electrocatalytic degradation of antibiotics

Abstract

Rapid industrialization and frequent oil spills have intensified water contamination from oil-water mixtures, while the excessive use of antibiotics has led to persistent waterborne residues, fueling global antibiotic resistance—a significant health concern. In this study, we developed hierarchically structured bifunctional Cu-based metal-organic framework (Cu-MOF) nanowire-coated copper mesh (MCM) membranes by forming Cu(OH)₂ nanowires through wet oxidation of copper mesh in situ, followed by their conversion into Cu-MOFs. The membranes feature a triple-tiered architecture consisting of a metallic substrate for efficient charge collection, vertically aligned nanowires to maximize active site exposure, and a defect-engineered MOF layer that enables selective permeation. The resulting MCM membranes exhibit a uniform nanowire array with a nanostructured rough surface, yielding superhydrophilicity and underwater superoleophobicity, as well as a high surface area. These membranes efficiently separate oil (n-hexane)-water mixtures with a high flux of 8.93 × 10³ L m⁻⁻² h⁻¹ and separation efficiency of 99.6 % and water-in-oil (n-hexane) emulsions with a high flux of 2.52 × 10³ L m⁻⁻² h⁻⁻¹ and separation efficiency of 99.3 %. Additionally, in electrocatalysis-assisted advanced oxidation processes (AOPs), MCM membranes demonstrated fast degradation rates for various antibiotics (e.g., 99.3 % degradation of tetracycline within 20 min). Overall, by combining membrane technology with electrocatalytic AOPs, MCM membranes offer a robust, dual-function solution for oil-water separation and antibiotic removal to provide sustainable and high-performance wastewater treatment.