Lignin modified Ti3C2Tx assisted construction of functionalized interface for separation of oil/water mixture and dye wastewater

Traditional separation materials based on Ti3C2Tx modification are susceptible to contamination by oily substances and have single performance, which limits their applications in treatment of actual oily wastewater. Here, to improve the hydrophilicity and stability of Ti3C2Tx, EHL-functionalized Ti3C2Tx (EHL-Ti3C2Tx) was prepared by enzymatic hydrolysis lignin (EHL) forming secondary bonds with the terminal oxygen-containing groups on the surface of Ti3C2Tx. EHL-Ti3C2Tx was further coated on polyurethane (PU) sponge to construct rough structures, enabling the modified EHL-Ti3C2Tx @PU sponge superhydrophilic/underwater superoleophobic wettability to achieve separation efficiency above 99.5% for different oil/water mixtures. Especially, the maximum permeation flux of EHL-Ti3C2Tx @PU for cyclohexane/water mixture separation is up to 231,321 L m−2 h−1. In addition, the functionalized interface constructed by EHL- Ti3C2Tx on mixed cellulose ester (MCE) membrane exhibits high permeability to malachite green and methylene blue cationic dyes with rejection rates of 99.1% and 98.1%, respectively. Therefore, two separation materials obtained by decorating EHL-Ti3C2Tx on PU and MCE substrates have extremely potential in treating complex wastewater.