Ultrathin 2D Ti3C2Tx MXene membrane for effective separation of oil-in-water emulsions in acidic, alkaline, and salty environment.

Layered Ti3C2Tx MXene is a two-dimensional (2D) metal carbide based material with high adsorption capacity and hydrophilicity, which is beneficial for oil/water separation. Herein, the Ti3C2Tx (T represents O, OH, and/or F) MXene membrane was obtained by depositing Ti3C2Tx MXene 2D nanosheets carbides onto porous polyvinylidene fluoride (PVDF) membranes by vacuum filtration. The as-prepared Ti3C2Tx MXene membrane exhibits excellent underwater superoleophobicity with oil contact angles (OCAs) close to 158° and oil sliding angles (OSAs) lower than 7°. In addition, the layered Ti3C2Tx MXene membrane can separate a series of stable emulsions even emulsified crude oil-in-water mixtures, and displays excellent separation efficiency over 99.4% and high permeation flux of 887 L m-2 h-1 bar-1. Furthermore, the Ti3C2Tx membrane displays superior durability to the corrosive liquids such as acidic, alkaline and salty, and can also effectively remove oil droplets from water in corrosive environment. This work provides a promising approach to prepare the ultrathin and layered 2D MXene Ti3C2Tx membrane for separation of stable emulsified oil-in-water mixtures separation.