Three-Dimensional MXene-Based Functional Materials for Water Treatment: Preparation, Functional Tailoring, and Applications

With the rapid development of economics and society, the water pollution and water shortage problem is becoming more and more severe. Excellent 3D separation functional materials for efficient water purification are highly required, but their design and fabrication still remain a big challenge at present. Benefiting from distinct advantages, such as 2D nanolamellar structure, high hydrophilicity, abundant functional groups, and desirable mechanical strength, 2D transition metal carbide/nitride materials, MXenes, have afforded a new platform for the creation of 3D water treatment functional materials. This review summarizes recent progress in 3D MXene-based functional materials toward wastewater treatment and water reclamation. In this review, common fabrication approaches for 3D MXene structures are emphatically summarized and recent developments of 3D MXene functional materials focused on the capacitive deionization (CDI), solar desalination, adsorption, and photocatalytic degradation of pollutants are critically reviewed. Besides, the impact of the structural design on their material performance is outlined. The critical challenges of 3D MXene materials in the aforementioned fields are also highlighted. Finally, we provide a brief perspective on the future development of 3D MXene materials toward practical effluent treatments.