A robust polypyrrole nanofibrous membrane for versatile applications: Oil-water separation and dye removal

Integrated approaches to oil-water separation and water remediation have significant implications for industrial applications and environmental sustainability. In this study, we focused on developing a versatile polypyrrole nanofibrous membrane (PPy NFM) based on electrospun nanofibrous membrane for the simultaneous and efficient separation of oil-in-water emulsions and removal of dyes from wastewater. PPy NFM with hydrophilicity and underwater oleophobicity exhibited good emulsion separation efficiency (96.7%) after 20 cycles of gravity-driven filtration. It is also highly resistant to harsh environments, including strong acids, bases, and high-concentration salts. Additionally, PPy NFM demonstrates remarkable removal efficiency for anionic dyes (91.9% ~ 99.3% at natural pH) and cationic dyes (41.3% ~ 58.0% at pH=10) with a strong affinity towards anionic dyes, through multiple interactions, including electrostatic forces, π-π stacking, and hydrogen bonding, as supported by experimental evidence and computational simulations. These results highlight the tremendous application potential of PPy NFM in simultaneous oil-water separation and dye removal.