Superwetting Ag@Cu2O anchored copper mesh for efficient oil/water separation and visible-light driven removal of organic pollutants

Abstract

The development of stable and durable oil/water separation materials with photocatalytic activity holds great significance for the purification of complex oily wastewater containing refractory organic pollutants. Herein, a multifunctional Ag@Cu₂O decorated copper mesh was designed and prepared via a two-step hydrothermal method. The material possesses outstanding superwettability, photocatalytic activity, and antibacterial properties towards Escherichia coli and Staphylococcus aureus. The mesh demonstrates remarkable and durable superhydrophilic properties while maintaining underwater superoleophobic characteristics, enabling excellent separation efficiency and high permeability flux involving various oil/water mixtures in gravity-driven separation processes. Under visible light, the Ag@Cu₂O anchored mesh serves as an effective photocatalyst in the removal of dyes and tetracycline antibiotics from aqueous solution. The catalyst shows high stability and reusability and exhibits high performance after 5 cycles of photocatalytic tests. Density functional theory calculations reveal that the improved photocatalytic performance is attributed to the narrowed indirect band gap after Ag anchoring. The silver atoms induce the shifting up of the energy level of the Cu 3d orbital, enhancing the photocatalytic activity of Cu₂O. The outstanding performance of the Ag@Cu₂O anchored mesh endows this material with great application potential in the removal of refractory pollutants from oily wastewater.