Carbon nanofiber@ZIF-8 derived carbon nanosheet composites with a core-shell structure boosting capacitive deionization performance

This work demonstrated the development of a hierarchical porous carbon-carbon composite used as an electrode material for capacitive deionization. The novel core-shell composite consisting of carbon nanofibers and N-rich porous carbon nanosheets (CNFZIF) was obtained by in situ growth of zeolitic imidazolate framework-8 (ZIF-8) nanosheets on electrospun nanofibers. By tailoring the composition and porosity of CNFZIF, ion transport and adsorption in the composite were tuned to achieve a large desalination capacity and a high desalination rate. Thanks to the synergistic effect of its N-rich carbon surface, high hydrophilicity, large specific surface area and unique hierarchical porous structure, the engineered CNFZIF sample exhibited an excellent capacitive deionization performance with a maximum desalination capacity of up to 50.88 mg g(-1) for NaCl solution and a high capacity retention rate of 97% after 30 cycles. Remarkably, CNFZIF also demonstrated high desalination capacities of 27.19 mg g(-1), 25.35 mg g(-1) and 20.46 mg g(-1) for CaCl2, MgCl2, and KCl solutions, respectively. This work provided a new route for the design of advanced electrode materials, and therefore represents a major step forward in the development of electrodes for capacitive deionization applications.

Automated summary

This work focused on the development of hierarchical porous carbon-carbon composites as electrode materials for capacitive deionization. By tailoring the composition and porosity of the composite, a large desalination capacity and high desalination rate were achieved. The engineered material exhibited excellent capacitive deionization performance for various ionic solutions, representing a significant advancement in electrode development for deionization applications.