A Novel Multifunctional Photocatalytic Separation Membrane Based on Single‐Component Seaweed‐Like g‐C3N4

Abstract Multifunctional separation membrane is usually realized by multi‐component collaborative construction, which makes the membrane preparation method complicated and uncontrollable. Herein, a novel multifunctional photocatalytic separation membrane is prepared by vacuum self‐assembly of single seaweed‐like g‐C 3 N 4 photocatalyst. The seaweed‐like g‐C 3 N 4 gives membrane certain roughness, large specific surface area, excellent hydrophilicity and abundant transport channels. Through a systematic study, the membrane exhibits excellent separation of five oil‐in‐water emulsions with a maximum flux of 3114.0 ± 113.0 L m −2 h −1 bar −1 for 1, 2‐dichloroethane‐in‐water (Dc/W) emulsion and a maximum efficiency of 97.4 ± 0.1% for chloroform‐in‐water (C/W) emulsion. In addition, the seaweed‐like g‐C 3 N 4 with large specific surface area and narrow bandgap render excellent visible light absorption characteristics and accelerate e − ‐h + pairs transport rate, giving the membrane excellent photocatalytic degradation and antibacterial properties. The membrane shows good degradation for eight different pollutants, among which the degradation effect for rhodamine B (RhB), methylene blue (MB), and crystal violet (CV) were ≈100%. The antibacterial efficiency against E. coli and S. aureus is also close to 100%. After 35 consecutive separations of C/W emulsion and 10 consecutive degradations of RhB, the membrane still maintains excellent separation performance. This long‐lasting multifunctional separation membrane exhibits broad application prospects in complex wastewater purification.