Polyphenol-metal manipulated nanohybridization of CNT membranes with FeOOH nanorods for high-flux, antifouling and self-cleaning oil/water separation

Carbon nanotube (CNT) membranes with nano-enhanced superwettability show great potential in high-efficient oil/water separation. In this study, we present a novel polyphenol-metal manipulated nanohybridization strategy to prepare CNT nanohybrid membranes embedded with FeOOH nanorods (NRs). The polyphenol-metal manipulated nanohybridization strategy lies in the assembly of polyphenol-metal (chitosan/tannic acid-Fe3+) complex primer on the CNT membranes followed by in situ FeOOH NRs mineralizating. The polyphenol-metal complex modulates the uniform distribution of in situ mineralized FeOOH NRs in the as-prepared CNT@CS/TA-FeOOH nanohybrid membrane, which endows the CNT nanohybrid membrane with both superhydrophilicity and underwater superoleophobicity. By integrating the high permeability of CNT membranes and the hydrophilicity and photo-degradation activity of FeOOH NRs, the CNT@CS/TA-FeOOH nanohybrid membrane possesses achieved a high water permeability above 8000 Lm(-2)h(-1)bar(-1) and greatly elevated flux recovery ratio above 97% for oil/water separation. Both hydration-induced antifouling property and photo-induced self-cleaning capability contributed to the robust flux recovery for highly efficient oil/water separation. The CNT@CS/TA-FeOOH nanohybrid membrane is promising for oily wastewater treatment applications, and the proposed polyphenol-metal manipulated nanohybridization strategy shows great potential for engineering various multifunctional nanohybrid membranes.