Electrosorption of anions with carbon nanotube and nanofibre composite film electrodes

The electrosorption of different salt solutions with carbon nanotube and nanofibre (CNT–CNF) composite film electrodes was studied. The electrochemical properties of CNT–CNF film were systematically investigated using ac impedance spectroscopy and cyclic voltammetry, and it was found that capacitive deionization (CDI) of CNT–CNF composite film electrodes is mainly due to Coulombic interaction on the electrical double-layer. Several experiments were conducted to determine the ion removal capacity and selectivity of CNT–CNF composite film electrodes, showing that smaller hydrated anions exhibit better CDI capacities.