摘要
MXene is a promising electrode material for energy storage and capacitive deionization (CDI) applications. In this study, a viable approach was developed to synthesize Ti 3 C 2 T x at different LiF/Ti 3 AlC 2 mass ratios of 0.5 – 2.0 for the enhanced CDI to remove different cations including hardness (Mg 2+ and Ca 2+ ), salt (Na + ), and ammonium (NH 4 + ) ions. The Ti 3 C 2 T x was fabricated using the hydrothermal method in the presence of LiF and HCl. The optimal mass ratio of 1.0 results in the formation of hydrophilic and well-delaminated nanosheets. Moreover, the Ti 3 C 2 T x -1 shows an interconnected meso-macroporous structure with a specific surface area of 48.4 m 2 /g. The Ti 3 C 2 T x MXene exhibits an exceptional electrochemical performance with a specific capacitance of 540 F g −1 at 5 mV s −1 in the presence of 1 M H 2 SO 4 . A remarkable desalination performance with the salt adsorption capacity (SAC) of 39.7 mg g −1 is obtained. The well-suited lattice fringe and inter-connected porous structure of the Ti 3 C 2 T x nanosheets accelerate the electron transport, which can maintain the cyclability over 50 cycles. This enhanced electron transport leads to an improved deionization capability during the CDI process. Moreover, the Ti 3 C 2 T x -based CDI device exhibits prominent selectivity for hardness ions with SACs of 43.8 and 39.5 mg g −1 for Ca 2+ and Mg 2+ , respectively. The SAC of NH 4 + can also be up of 39.7 mg g −1 at 1000 mg L −1 . Results in this study clearly elaborate the promising potentiality for the utilization of MXene as an effective electrode material for desalination and other electrochemical applications.