Hierarchically Stabilized PAN/β-FeOOH Nanofibrous Membrane for Efficient Water Purification with Excellent Antifouling Performance and Robust Solvent Resistance

ACS Appl Mater Interfaces. 2019 Sep 18;11(37):34487-34496. doi: 10.1021/acsami.9b12855. Epub 2019 Sep 9.

Abstract

Filtration membranes, with good antifouling performance and robust solvent resistance (e.g., organic solvents or highly acidic/alkaline/saline solvents), that can effectively purify complex polluted water systems are especially demanded in practice but present a challenge to be conquered. Herein, a simple method has been demonstrated to address the obstacles, applying the stabilized polyacrylonitrile (SPAN) nanofiber/β-FeOOH nanorod composite membrane as a model. In this work, simply stabilizing PAN nanofibers in air can achieve robust solvent resistance against organic solvents and strong inorganic acidic/alkaline/saline solutions. Hydrophilic β-FeOOH nanorods were anchored onto SPAN nanofibers of our electrospun membrane and achieve superhydrophilicity (0°)/underwater superoleophobicity (>155°) for various oils. More importantly, the SPAN/β-FeOOH nanofibrous membrane exhibits robust mechanical strength (274 MPa of Young's modulus), excellent chemical stability, fast separation flux (2532-10146 L m-2 h-1), and satisfying removal ratio (>98.2%) against insoluble oils and soluble cationic dyes. In addition, good photocatalytic activity against organic pollutants provides our membranes with excellent flux restorability and a long-term use capacity. These outstanding performances endow our membrane with a great potential application in purifying polluted aquatic systems in worldly harsh conditions.

Keywords: dual-functional wastewater purification; nanofibrous membrane; solvent resistant; superwettability; visible-light degradation.