Fabrication of carbon nanorods and graphene nanoribbons from a metal–organic framework

Electrospun metal–organic framework derived hierarchical carbon nanofibers with high performance for supercapacitors

A novel N-doped MOF-based hierarchical carbon fiber (NPCF) towards supercapacitors was prepared by the pyrolysis of MOF nanofibers.

Two-dimensional graphene-like N, Co-codoped carbon nanosheets derived from ZIF-67 polyhedrons for efficient oxygen reduction reactions

Graphene-like N, Co-codoped carbon nanosheets have been fabricated from ZIF-67 in a molten salt medium.

Fabrication of morphology-preserved microporous carbon from a zeolitic-like porous coordination polymer

A new zeolitic-like microporous coordination polymer (PCP), [Zn₂(L)·2H₂O]·xguest, was firstly converted to morphology-preserved carbon rods with exclusive micropores and a large surface area for selective gas capture.

Pyrolysis of covalent organic frameworks: a general strategy for template converting conventional skeletons into conducting microporous carbons for high-performance energy storage

A general strategy based on template pyrolysis enables the conversion of conventional covalent organic frameworks into conducting microporous carbons with exceptional energy storage performance.

Low-crystalline mesoporous CoFe2O4/C composite with oxygen vacancies for high energy density asymmetric supercapacitors

A low-crystalline mesoporous cobalt ferrite and carbon composite (L-CoFe₂O₄/C) material was prepared via a sol–gel approach and calcination process. An L-CoFe₂O₄/C//AC asymmetric supercapacitor exhibited high energy density and power density.

Nanoarchitectures for Metal-Organic Framework-Derived Nanoporous Carbons toward Supercapacitor Applications

The future advances of supercapacitors depend on the development of novel carbon materials with optimized porous structures, high surface area, high conductivity, and high electrochemical stability. Traditionally, nanoporous carbons (NPCs) have been prepared by a variety of methods, such as templated synthesis, carbonization of polymer precursors, physical and chemical activation, etc. Inorganic solid materials such as mesoporous silica and zeolites have been successfully utilized as templates to prepare NPCs. However, the hard-templating methods typically involve several synthetic steps, such as preparation of the original templates, formation of carbon frameworks, and removal of the original templates. Therefore, these methods are not favorable for large-scale production. Metal-organic frameworks (MOFs) with high surface areas and large pore volumes have been studied over the years, and recently, enormous efforts have been made to utilize MOFs for electrochemical applications. However, their low conductivity and poor stability still present major challenges toward their practical applications in supercapacitors. MOFs can be used as precursors for the preparation of NPCs with high porosity. Their parent MOFs can be prepared with endless combinations of organic and inorganic constituents by simple coordination chemistry, and it is possible to control their porous architectures, pore volumes, surface areas, etc. These unique properties of MOF-derived NPCs make them highly attractive for many technological applications. Compared with carbonaceous materials prepared using conventional precursors, MOF-derived carbons have significant advantages in terms of a simple synthesis with inherent diversity affording precise control over porous architectures, pore volumes, and surface areas. In this Account, we will summarize our recent research developments on the preparation of three-dimensional (3-D) MOF-derived carbons for supercapacitor applications. This Account will be divided into three main sections: (1) useful background on carbon materials for supercapacitor applications, (2) the importance of MOF-derived carbons, and (3) potential future developments of MOF-derived carbons for supercapacitors. This Account focuses mostly on carbons derived from two types of MOFs, namely, zeolite imidazolate framework-8 (ZIF-8) and ZIF-67. By using examples from our previous works, we will show the uniqueness of these carbons for achieving high performance by control of the chemical reactions/conditions as well proper utilization in asymmetric/symmetric supercapacitor configurations. This Account will promote further developments of MOF-derived multifunctional carbon materials with controlled porous architectures for optimization of their electrochemical performance toward supercapacitor applications.

In situ electrochemical activation of Ni-based colloids from an NiCl2 electrode and their advanced energy storage performance

The formation of electrochemical activated cations in electrode materials to induce multiple-electron transfer reactions is a challenge for high-energy storage systems. Herein, highly electroactive Ni-based colloidal electrode materials have been synthesized by in situ electrochemical activation of a NiCl₂ electrode. The highest specific capacitance of the activated Ni-based electrodes was 10 286 F g^-1 at a current density of 3 A g^-1, indicating that a three-electron Faradaic redox reaction (Ni³⁺ ↔ Ni) occurred. Upon potential cycling and constant potential activation, a decrease in the charge transfer resistance can be found. Activation and utilization of multiple-electron reactions is an efficient route to increase the energy density of supercapacitors. This newly designed colloidal pseudocapacitor is compatible with inorganic pseudocapacitor chemistry, which enables us to use metal cations directly via their commercial salts rather than their oxide/hydroxide compounds.

Redox-responsive, core-crosslinked degradable micelles for controlled drug release

We developed novel redox-responsive, core-crosslinked micelles (CCLMs) via a simple, one-step click chemistry reaction.