Carbonization

Nanotechnology

Electrode

Organic chemistry

Activated carbon

Imidazolate

Membrane

Porosity

Biology

Composite number

Nanopore

Adsorption

Engineering

Catalysis

Carbon fibers

Physical chemistry

Specific surface area

Composite material

Chemistry

Materials science

Scanning electron microscope

Desalination

Capacitive deionization

Electrolyte

Capacitance

Chemical engineering

Genetics

Supercapacitor

ACS Applied Materials & Interfaces

Herein, the synergistic effects of hollow nanoarchitecture and high specific surface area of hollow activated carbons (HACs) are reported with the superior supercapacitor (SC) and capacitive deionization (CDI) performance. The center of zeolite imidazolate framework-8 (ZIF-8) is selectively etched to create a hollow cavity as a macropore, and the resulting hollow ZIF-8 (HZIF-8) is carbonized to obtain hollow carbon (HC). The distribution of nanopores is, subsequently, optimized by KOH activation to create more nanopores and significantly increase specific surface area. Indeed, as-prepared hollow activated carbons (HACs) show significant improvement not only in the maximum specific capacitance and desalination capacity but also capacitance retention and mean desalination rates in SC and CDI, respectively. As a result, it is confirmed that well-designed nanoarchitecture and porosity are required to allow efficient diffusion and maximum electrosorption of electrolyte ions.

KOH-Activated Hollow ZIF-8 Derived Porous Carbon: Nanoarchitectured Control for Upgraded Capacitive Deionization and Supercapacitor