Design of nitrogen-doped cluster-like porous carbons with hierarchical hollow nanoarchitecture and their enhanced performance in capacitive deionization

The electrode material with high electrosorption capacity and fast electrosorption rate is highly desired in capacitive deionization (CDI) process. To meet this demand, the nitrogen-doped cluster-like porous carbons (NCPCs) with hierarchical hollow nanoarchitecture were rationally prepared by carbonizing the polydopamine/nano-ZnO composite and employed as CDI electrodes. The resultant NCPCs possess an interconnected hierarchical structure with a hollow cavity, nitrogen-doping property, high specific surface, large pore volume and good wettability. All these merits can ensure a huge accessible electrosorption interface for the very quick diffusion of ions so that achieve an excellent CDI performance. Particularly, the sample carbonized at 900 degrees C (NCPC-900) with the optimal porous structure and chemistry composition exhibits the highest electrosorption capacity of 11.98 mg g(-1) in 100 mg L-1 NaCl solution. Besides, the NCPC-900 electrode shows a good cycle stability over 20 electrosorption-desorption cycles. These results render that the NCPCs have the great potential as the electrode material for high performance CDI desalination.