Metal-organic framework-engaged formation of a hierarchical hybrid with carbon nanotube inserted porous carbon polyhedra for highly efficient capacitive deionization

Capacitive deionization (CDI) is an emerging desalination technique to offer clean water. In order to obtain high CDI performance, a rationally designed structure of electrode materials has been an urgent need for CDI application. Here for the first time a hierarchical porous carbon nanotube (CNT)/porous carbon polyhedra (PCP) (hCNT/PCP) hybrid was fabricated via in situ insertion of CNTs into ZIF-8 and a subsequent pyrolysis process. The potential of the hCNT/PCP hybrid for CDI application was demonstrated, and the results indicate that the hCNT/PCP hybrid exhibits a high electrosorption capacity of 20.5 mg g^-1 with stable cycling stability due to its novel CNT-inserted-PCP porous structure, high specific surface area and good electrical conductivity. It should be expected that hCNTs/PCP should be a promising candidate for highly efficient CDI electrode materials.