Improving the capacitive deionisation performance by optimising pore structures of the electrodes

In this paper, three types of ordered mesoporous carbons (OMCs) were synthesised by an original template method and a modified sol-gel process involving nickel salts. The effects of pore arrangement pattern (ordered and random), and pore size distribution (mesoporous and microporous) on the desalination performance were investigated by comparing mesoporous carbons with activated carbons (ACs). It is found that the mesoporous carbons prepared by addition of nickel salts demonstrated higher specific capacitances than mesoporous carbons without nickel salts and the activated carbon electrodes. Their electrosorptive deionisation properties were also compared in a dilute NaCl solution (conductivity 100 μScm-1), the amount of adsorbed ions are measured by a flow though apparatus in the laboratory. It is found that the amounts of the adsorbed ions are 15.9 μmolg-1 for OMCs involving nickel in the synthesis process, 10.3 μmol g-1 for OMC not involving nickel salts and 4.7 μmol g-1 for ACs.