Preparation of TiO2/Ti3C2Tx Composite for Hybrid Capacitive Deionization

The shortage of fresh water resources resultes from the rapid growth of population and industrial development. Desalination of seawater and brackish water is an effective way to alleviate the freshwater crisis. In this work, the TiO2/Ti3C2T, composites were prepared by directly calcinating Ti3C2Tx for hybrid capacitive deionization (HCDI). The results show that the calcination temperature has a significant impact on morphology, structure, electrochemical and desalination behavior of the TiO2/Ti3C2T, composites. To constitute the full HCDI device, the optimized TiO2/Ti3C2Tx and acid treated activated carbon (AC) was employed as cathode and anode, respectively. In the constant voltage mode, the salt removal capacity of TiO2/Ti3C2Tx parallel to AC reached 23.8 mg.g(-1) under the cell voltage of 1.2 V in NaCl solution with an initial conductivity of 3000 mu S.cm(-1). After 20 cycles, the capacity retention rate remains at 78%. Besides, through exploring the morphology and crystal texture evolution of TiO2/Ti3C2Tx electrodes before and after desalination, it is found that the desalination of TiO2/Ti3C2Tx electrodes may be achieved due to the intercalation of sodium ions into the Ti3C2Tx interlayer.