Abstract

  Capacitive desalination (CDI) has aroused much attention due to its advantages of low energy consumption and nvironmental compatibility. However, typical CDI processes display limited effciency. In this work, onedimensional V2O5 with nanocuboid structure was prepared with MXenes(V2C) precursor for the frst time,which has high adsorption capacity, structure stability and fast ion diffusion ability. The as-synthesized V2O5 electrode achieved a salt adsorption capacity(SAC) of 55.2 mg NaCl g- 1 V2O5 under optimized conditions with a constant current density of 30 mA g- 1, a voltage range from - 0.6 to 1.2 V, and an initial solution of 500 mg L-1 NaCl. Furthermore, from the comprehensive analysis of mechanism, due to the high conductivity and low charge transfer resistance of V2O5 electrode, it reduces the energy loss of the resistance during desalination. A particularly low energy consumption of 0.27 kWh kg-1-NaCl is reached when the operation is carried out successfully at low voltage range, indicating the advantages of energy saving and high effciency. Therefore, V2O5 is an attractive and promising electrode material, which exhibits the potential of pseudocapacitive materials with certain structure for practical CDI application in future and inspires us to have a deep insight into the effect of morphology on the properties.

Keywords: Capacitive deionization, V2O5, MXenes, Nanocuboid, Desalination