A flexible Ti 3 C 2 T x (MXene)/paper membrane for efficient oil/water separation.

The scalable fabrication of flexible membranes for efficient oil/water separation is in high demand but still significantly underdeveloped. Here, we present a flexible membrane using Ti 3 C 2 T x (MXene) as the functional layer on conventional print paper as the substrate. With a simple coating process using MXene ink, we developed a highly hydrophilic and oleophobic membrane with an underwater oil contact angle of 137°. Such a simple membrane shows outstanding flexibility and robustness, and demonstrates a facile approach for membrane scale-up using MXene ink on low-cost print paper. The membrane shows high separation efficiency for oil/water emulsions, of over 99%, and a high water permeation flux of over 450 L per m 2 per h per bar. We demonstrate the excellent anti-fouling property of this membrane by cleaning the membranes without chemicals. These low-cost, highly efficient, anti-fouling membranes can provide new opportunities for industrial oil/water separation applications.