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Na 3 (VO) 2 (PO 4) 2 F nanocuboids wrapped by graphene as a faradic electrode applied in HCDI and received a superior desalination performance with a high desalination capacity of 175.94 mg·g−1, a low energy consumption of 0.35 kWh·kg-NaCl−1, and the energy recovery is 20% at a current density of 25 mg·g−1. [Display omitted] • Na 3 (VO) 2 (PO 4) 2 F@rGO was applied firstly in capacitive deionization. • Na 3 (VO) 2 (PO 4) 2 F@rGO has a superior desalination performance (175.94 mg·g−1). • Low energy consumption of 0.35 kWh·kg-NaCl−1was achieved.. • NVOPF@rGO display a promising ability for desalination. Capacitive deionization (CDI) is considered as a promising desalination technology due to its low energy consumption and no two-second pollution. But the development of traditional CDI is limited by its two drawbacks, which are low deionization capacity and unavoidable parasitic reactions. Hybrid capacitive deionization (HCDI), which is composed of a faradic electrode and an electrical-double-layer electrode, effectively solves the above problem. Herein, we report a typical NASICON material Na 3 (VO) 2 (PO 4) 2 F and modify it with rGO, then apply it in HCDI firstly and receive a superior desalination performance. Five samples are prepared by adding different contents GO solution and we choose the best one (NVOPF-4) with the lowest resistance for the desalination tests according to electrochemical performance. The result of desalination shows a high desalination capacity of 175.94 mg·g−1, low energy consumption of 0.35 kWh·kg-NaCl−1, and the energy recovery is 20% at a current density of 25 mg·g−1. NVOPF@rGO displays a promising ability for desalination in capacitive deionization, further confirming NASICON be a suitable material type for HCDI electrode materials. [ABSTRACT FROM AUTHOR]

• LiF/HCL-etched Ti 3 C 2 T x MXene was applied firstly in capacitive deionization. • Increase interlayer spacing and reduce the content of –F in termination groups. • An ultrahigh desalination capacity of 68 mg·g−1 is achieved. • Relatively low energy consumption of 0.24 kWh/kg-NaCl is achieved. • LiF/HCl-etched Ti 3 C 2 T x displays a promising ability for desalination. MXene has been known as an important candidate material in the field of electrochemical energy storage. Different etching methods have an important effect on the properties of MXene. Herein, we prepared Ti 3 C 2 T x MXene by LiF/HCL-etching method and applied it firstly in capacitive deionization. The method of LiF/HCl-etching is beneficial to increase the interlayer spacing of Ti 3 C 2 T x and reduce the content of –F in termination groups which are favourable for ion transport. An ultrahigh desalination capacity of 68 mg·g−1 is achieved at a current density of 20 mA·g−1 and a voltage window of 1.2 V. Furthermore, the relatively low energy consumption of 0.24 kWh/kg-NaCl is achieved, and the energy recovery is 5.44%. The LiF/HCl-etched Ti 3 C 2 T x displays a promising ability for desalination in capacitive deionization, making Ti 3 C 2 T x be a promising candidate for CDI electrode materials. [ABSTRACT FROM AUTHOR]