MXene sheets surface constructed a strong hydrogel coating for sustainable oily wastewater separation

Abstract

Membrane separation technology can effectively address the issues of high energy consumption and low efficiency encountered in traditional separation processes. However, oil fouling hinders the widespread adoption of membrane technology in the field of oil-water separation. Therefore, preventing membrane fouling is crucial for overcoming this bottleneck. Titanium carbide (Ti3C2Tx, MXene), a recent addition to the two-dimensional material family, has garnered significant interest in the domain of water treatment owing to its controllable surface groups, hydrophilic nature, antimicrobial properties, and high electrical conductivity. Hence, we proposed a strategy to construct hydrogel coatings on carboxylated MXene surfaces. Moreover, the rigidity of the hydrogel framework was further improved by introducing CaCO3 nanoparticles. A stronger hydrogel layer ensured that the hydration layer is difficult to contaminate with oil and the fastness of the membrane material. Naturally, the as-prepared membrane showed excellent separation performance for a wide range of emulsions, maintaining high levels (3979.5 L m–2 h−1 bar−1 and 99.96 %) after 5 consecutive separation cycles of 200 min. Additionally, the membrane separated emulsions containing acids, salts, or alkali with a permeability of 2982.8 L m–2 h−1 bar−1 after 40 min; it also treated actual oily wastewater achieving a permeability of 238.9 L m–2 h−1 bar−1 and showed high removal efficiency (>99.9 %) for several heavy metals (Cu, Li, Pb, Se, and V), as well as antimicrobial (92.5 %) properties that enhance its potential for industrial applications. This study offers a new idea for designing anti-oil-fouling MXene oil-water separation membranes.