Polyvinylidene fluoride membrane functionalized with zero valent iron for highly efficient degradation of organic contaminants

Abstract

A hierarchical polyvinylidene fluoride (PVDF) membrane functionalized with catalytic zero valent iron nanoparticles via polydopamine/polyethyleneimine was successfully fabricated. The catalytic membrane exhibited excellent degradation performance for toxic 4-nitrophenol (4-NP), Rhodamine B (RB), and 2,4-dichlorophenol (2-CP). With a trace amount of H2O2 flowing over the surface of the catalytic membrane, highly active sites were monitored. The active surfaces generated a large amount of •OH radicals via decomposition of H2O2. The radicals unselectively oxidized a wide range of recalcitrant organic pollutants. Specifically, ~ 80% RB and almost 100% 4-NP and 2-CP were degraded within 30 min in aqueous solutions. Furthermore, total organic carbon analysis revealed that recalcitrant RB, 4-NP and 2-CP molecules could be partially mineralized into carbon dioxide and water inside the membrane. The degradation mechanism was related to a Fenton-like reaction. The catalytic membrane showed high regeneration ability with approximately 100% activity retention after four consecutive use cycles.