Chinese dumpling-like NaTi2(PO4)3/MXene@reduced graphene oxide for capacitive deionization with high capacity and good cycling stability

Authors：Shen, Xiaojie; Xiong, Yuecheng; Yu, Fei^*; Ma, Jie^*

Source：Journal of Materials Chemistry A, 2023, 11(32): 17263-17271.

DOI：10.1039/d3ta02715e

• SEAWATER DESALINATION
• PERFORMANCE
• ELECTRODE
• FUTURE
• ENERGY
• MXENE
• CDI

Capacitive deionization (CDI) has emerged as a potential energy-efficient desalination technique to provide fresh water from brine, and the rational design of deionization electrodes remains a challenge. Cation insertion materials hold great potential in desalination and selective ion separation due to suitable space to intercalate cations; however, intrinsically low electrical conductivity and poor stability impede their further application in CDI. In this research, a partial in situ derivation tactic was proposed to address these problems by using Ti-based MXenes as metal precursors. The as-prepared NTP-MXene/rGO hybrid resembles the morphology of dumplings, where MXene/rGO serves as the skin to protect the NTP filling and enhance its electrical conductivity. This composite electrode material exhibited an outstanding salt adsorption capacity (SAC) of 251.55 mg g(-1) in constant current mode with a specific current of 50 mA g(-1) (cutoff voltage: 1.8 V; initial NaCl concentration: 10 mM), far higher than those of reported materials. Moreover, low energy consumption (0.19 kW h kg(NaCl)(-1)) was obtained at a cutoff voltage of 1 V, and stable cycling performance (approximately 80% capacity was retained after 100 cycles) makes M-NTP/rGO a suitable electrode for practical applications, proving that partial derivation is an attractive strategy in rational design of CDI electrodes.

• Institution
  同济大学