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

Abstract

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.

CoZn/N-Doped porous carbon derived from bimetallic zeolite imidazolate framework/g-C3N4 for efficient hydrodeoxygenation of vanillin

“…All ZIF/g-C 3 N 4 composites exhibit the same crystallographic structure (see XRD in Fig. S1 †), which is in line with Co-Zn-ZIF, 31 verifying the successful formation of zeolitic imidazolate frameworks (ZIFs).…”

Recent advances in metal-free catalysts for the remediation of antibiotics, antibiotic resistant bacteria (ARB), and antibiotic resistant genes (ARGs)

“…In addition, the prepared PC had a large surface area (2051 m 2 g À1 ), which was about 20 times that of the rice husk derived carbon. Similarly, Kim et al 67 selectively etched the center of zeolite imidazolate framework-8 to obtain a hollow carbon (Fig. 8c).…”

“…63 Fig. 8 Fabrication of N-doped and hierarchical PC ((a) with permission from the American Chemical Society), 65 preparation of PC via etching out natural silica ((b) with permission from the American Chemical Society), 66 optimization of hollow carbon by KOH activation ((c) with permission from the American Chemical Society), 67 and synergistic effect between adsorption and catalytic reactions in PC induced PS-based AOPs ((d) with permission from the American Chemical Society). 68 prepared PC with an extremely high surface area (>4500 m 2 g À1 ), exhibiting excellent adsorption capacity towards phenol (Fig.…”

Influence of carbon electrode thickness and spacing on capacitive deionization performance

“…However, the improvement of electrosorption performance by enhancing the electrode materials is still challenging (Kim et al, 2021;Lee et al, 2018;Porada et al, 2013b;Torkamanzadeh et al, 2020). In general, electrosorption capacity of the CDI system is directly proportional to the available surface area of the electrode.…”