anchor of NaTiO in nitrogen-rich carbon hollow red blood cell-like structure as a 0D-3D hierarchical electrode material for efficient electrochemical desalination.

Reasonable design of the structure and complementary compounding of electrode materials is helpful to enhance capacitive deionization (CDI) performance. Herein, a novel 0D-3D hierarchical electrode material containing NaTiO nanoparticles anchored at hollow red blood cell (HRBC)-like nitrogen-rich carbon (HRBC-NTO/N-C-60) was prepared selective protection, pyrolysis, and alkalization. Specifically, a HRBC-like NH-MIL-125-based material (HRBC-MOF-60) was first constructed by a selective protection approach of tannic acid (TN), which addresses the shortcomings of using sacrificial templates or corrosive agents. Afterwards, HRBC-NTO/N-C-60 was obtained by annealing and alkalization of HRBC-MOF-60. The nitrogen-rich carbon with a HRBC-like structure has the ability to rapidly transport electrons, and its porous structure enables remarkable charge transfer. Benefiting from the grafted 3D N-doped porous carbon with a HRBC-like structure, well-dispersed 0D NaTiO nanoparticles, and satisfactory bonding effects, HRBC-NTO/N-C-60 exhibited high specific capacitance and fast ionic and electronic diffusion kinetics. Moreover, HRBC-NTO/N-C-60 was well-suited for desalination by functioning as a cathode material for capacitive deionization (CDI), and delivering a high desalination capacity of 66.8 mg g in 200 mg L NaCl solution at 1.4 V. This work introduces an excellent high-performance candidate for electrochemical deionization as well as affording afflatus for accurately inventing OD-3D hierarchical materials with hollow structures.