High‐Efficient Capacitive Deionization Using Amine‐Functionalized ZIF‐67@ 2D MXene: Toward Ultrahigh Desalination Performance

Capacitive deionization (CDI) is proposed as a thermodynamically effective desalination method for treating non‐potable water with a low‐salt concentrator to address the growing need for clean drinking water. MXenes, 2D transition metal carbides derived from M n+1 AX n ( n = 1, 2, 3, or 4) bulk phases, are an intriguing class of crystalline materials with unique physicochemical properties. However, a significant challenge for their practical use is the degradation and phase transition experienced by MXene flakes when exposed to aqueous conditions. Several strategies for improving MXene stability are proposed, including combining it with porous materials such as carbon and metal–organic frameworks (MOFs). In addition to ZIFs, antioxidants with amine functional groups are used to stabilize MXene. Additionally, amine‐functionalized MXenes exhibit improved resistance to oxidation caused by water, enabling them to maintain their dispersity in aqueous solutions at room temperature. The produced A‐ZIF@MXene electrode represents high desalination performance with the highest salt adsorption capacity up to 80.3 mg g −1 in 1000 mg L −1 The NaCl solution reserve more than 99% of its initial capacity in 50 cycles to the synergism of its surface amine groups, high hydrophilicity, and distinctive hierarchical porous structure.