Synthesis of a spherical carbon-TiO ₂ composite as electrode material for capacitive deionization

Activated carbon is widely used as an electrode material for capacitive deionization. However, it has low wettability with electrolytes and a low ion-adsorption capacitance. To enhance the wettability of activated carbon, in this study, a carbon-metallic oxide composite was synthesized using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)-block copolymer and titanium dioxide (TiO ₂ ). The TiO ₂ supporting material was synthesized by a sol-gel method, and activated carbon was prepared by high-temperature calcination at 550 °C in a nitrogen atmosphere. The active material containing 50 % TiO ₂ exhibited the highest positive and negative capacitances of 109.5 and 121.3 F g ^-1 , respectively. Finally, when this material was used as a capacitive deionization electrode, the maximum ion removal rate was approximately 92 %. These results indicate that the carbon-TiO ₂ composite electrode was more effective than the raw carbon electrode. In the end, we demonstrated the potential of a metallic oxide with activated carbon for desalination water treatment.