Advancements in Electrode Materials: The Role of MXenes in Capacitive Deionization Technology

As the demand for clean water rises, the need for advanced materials and technologies intensifies. Capacitive deionization (CDI) has gained attention for water treatment including brackish water desalination, wastewater recycling, and selective resource recovery. Electrode materials play a critical role in CDI’s electrochemical performance, with MXenes, two-dimensional transition-metal carbides, and nitrides, offering a promising solution for low-energy brackish water desalination. MXenes possess excellent structural and electrochemical properties, overcoming limitations like concentration polarization in conventional CDI electrodes and reducing energy consumption. This review discusses MXenes’ properties and various preparation strategies, including intercalating agents, surface modification, heteroatom introduction, and 3D structure design. It also explores MXenes’ potential in CDI applications for seawater desalination, NH4+ recovery, and ion-selective removal, emphasizing their material and environmental benefits. The review concludes by suggesting future research directions for MXenes in CDI technology.