A Novel Multifunctional Photocatalytic Separation Membrane Based on Single‐Component Seaweed‐Like g‐C ₃N ₄

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 ₃N ₄ photocatalyst. The seaweed‐like g‐C ₃N 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 ₃N 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.