It were revealed from X-ray diffraction and N2 sorption measurements that AC has both
micropores and mesopores, whereas ordered mesopores are dominant in OMC. Their
performance as potential electrodes to remove salt was evaluated by cyclic voltammetry
(CV) and galvanostatic charge/discharge tests at a range of electrolyte concentrations and
sweep rates. It is deduced that under the same electrochemical condition the specific
capacitance values of OMC electrode (i.e. 133 F/g obtained from CVat a sweep rate of 1 mV/s
in 0.1M NaCl solution) are larger than those of AC electrode (107 F/g), suggesting that the
former has a higher desalting capacity than the latter. Furthermore, the OMC electrode
shows a better rate capacity than the AC electrode. In addition, the desalination capacities
were quantified by the batch-mode experiment at low voltage of 1.2V in 25ppm NaCl
solution (50 ms/cm conductivity). It was found that the adsorbed ion amounts of OMC and
AC electrodes were 11.6 and 4.3 mmol/g, respectively. The excellent electrosorptive
desalination performance of OMC electrode might be not only due to the suitable pore
size (average of 3.3 nm) for the propagation of the salt ions, but also due to the ordered
mesoporous structure that facilitates desorption of the salt. Based on the results, it was
found that the development of an ordered mesoporous structure and the control of the
number of micropores are two important strategies for optimising electrode material
properties for electrosorptive deionisation.