Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater. Herein, we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine (PAN-ETA) membrane with the aid of a chitosan (CS)-TiO 2 layer via vacuum filtration and in-situ partial reduction. The introduction of the CS-TiO 2 layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles. The PAN-ETA/CS-TiO 2 /Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux (~ 47 L·m −2 ·h −1 ·bar −1 ) and dyes rejection (methyl orange: 88.22%; congo red: 95%; methyl blue: 97.41%; rose bengal: 99.98%). Additionally, the composite membranes exhibited potential long-term stability for dye/salt separation (dye rejection: ~97%; salt rejection: ~6.5%). Moreover, the methylene blue and rhodamine B solutions (20 mL, 10 mg · L −1 ) were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min. This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.