In situ constructed Ti3C2Tx MXene/polypyrrole composite with enhanced sodium storage capacity for efficient hybrid capacitive deionization

Two-dimensional layered material Ti3C2Tx MXene is considered an excellent capacitive deionization (CDI) electrode material due to its two-dimensional structure and high conductivity. However, the self-stacking of MXene limits its structural stability and effective ion accommodation in CDI field. In this work, Ti3C2Tx MXene/polypyrrole (PPy) is synthesized by in situ polymerization of conductive PPy on the surface of Ti3C2Tx MXene nanosheets. The hybrid not only effectively alleviates the self-stacking of MXene to improve the structure stability, but also combines the high conductivity of MXene and the excellent electrochemical capacity of PPy. Therefore, when used as HCDI electrode, Ti3C2Tx MXene/PPy displays an excellent desalination performance including a high desalination capacity of 50.64 mg g(-1), a superior desalination rate of 16.5 mg g(-1) min(-1) and excellent cycling stability. Ti3C2Tx/PPy should be a very promising electrode material for highly efficient desalination.

Automated summary

This study synthesized Ti3C2Tx MXene/Polypyrrole (PPy) hybrid material by in situ polymerization of conductive PPy on the surface of Ti3C2Tx MXene nanosheets. The hybrid not only alleviates self-stacking of MXene and improves structural stability, but also combines high conductivity of MXene with excellent electrochemical capacity of PPy, demonstrating outstanding desalination performance when used as an HCDI electrode.