Three-dimensional and flexible carbon nanofiber mat by one-step electrospinning for efficient oil/water separation

Electrospun carbon materials are widely used in oil-water separation because of their excellent hydrophobicity and lipophilicity, good chemical stability, designable structure and easy adjustment of porosity. However, the traditional electrospun carbon fiber materials are often flat membranes with poor flexibility. Herein, a three-dimensional (3D) flexible carbon nanofiber mat (CNFM) was fabricated by humidity-induced electrospinning and followed carbonization processing. Polyacrylonitrile (PAN) was used as the carbon source while polyvinylpyrrolidone (PVP) was used as the pore-forming and nitrogen doping component. CNFM-60 exhibited a hydrophobic surface (WCA≈137.5°), large oil flux (4036 L m−1 h−1), exceptional oil-water separation efficiency (>98.5%), and good oil adsorption performance (oil that weighs 48 times its own) with superior flexibility. Thus this material has great potential for efficient oil-water separation in various circumstances.