Capacitive deionization using wrinkle-engineered Nb4C3Tx-MXene freestanding membranes

MXene species have emerged as a class of compelling electrode materials in the field of capacitive deionization (CDI). However, as an excellent member of the MXene family, the Nb4C3Tx has not received much attention in terms of CDI. Herein, we have not only established the feasibility of Nb4C3Tx as a potential desalination electrode materiel but also proposed a wrinkle-engineering strategy that can effectively improve the CDI performance of Nb4C3Tx freestanding membranes. Specifically, the introduction of wrinkles on Nb4C3Tx nanosheets contributes to optimizing the interlayer space, accessibility, conductivity, stability, and CDI performance of the assembled membranes. In particular, the optimized wrinkled Nb4C3Tx membranes can achieve an ultrahigh desalination capacity of similar to 188.2 mg g(-1) at 1.6 V accompanied by a fast adsorption rate of similar to 12.6mg g(-1) min(-1), showing great competitiveness with other MXene individual electrodes. In addition, the as-designed electrodes also exhibit superior cycle desalination stability as well as good applicability to different salts (such as LiCl, KCl, CaCl2, and MgCl2). This work both extends the MXene material applicable to CDI and offers an effective solution for improving the properties of Nb4C3Tx-MXene lamellar membrane electrodes, opening up enormous opportunities for the use of such MXene species in the field of electrochemical desalination.