A bifunctional heterostructured membrane for efficient emulsion separation and photocatalytic degradation of waterborne organic pollutants

Oily wastewater discharge from industrial activities and oil spills constitutes a crucial environmental issue exacerbated by the presence of water-soluble organic pollutants. Developing efficient superwetting membrane materials capable of separating oil and water while degrading water-soluble organic pollutants is therefore highly desirable. In this study, we prepared I-doped Bi2O2CO3/g-C3N4 heterojunction structures using a hydrothermal method utilizing graphitic carbon nitride (g-C3N4) as the carbon source, which were uniformly distributed on the mesh of Co3O4 nanowire clusters to obtain the heterojunction membrane. The heterojunction membrane demonstrates superhydrophilicity and underwater superoleophobicity, with excellent separation efficiency and outstanding permeability for oil-in-water emulsions. Additionally, the membrane exhibits good stability, superior anti-corrosive property, remarkable reusability, and near-complete degradation of several water-soluble organic dyes under visible-light irradiation. Therefore, this study provides a novel design strategy for multifunctional membranes that achieve effective treatment of complex oil-containing wastewater.