Covalent Organic Frameworks (COFs)/MXenes Heterostructures for Electrochemical Energy Storage

Abstract

Covalent organic frameworks (COFs), a distinguished class of porous materials exhibiting precise modularity and crystallinity, and two-dimensional (2D) MXenes, a highly conductive, atomic layered transition metal carbides or nitrides or carbonitrides, are the two fascinating classes of advanced materials that have been intensively researched for energy storage recently. Thanks to the high surface area and porosity of COFs and high electrical conductivity coupled with highly redox active surfaces of MXenes, they have shown great potential in the energy storage applications such as batteries and supercapacitors. However, their electrochemical performance is limited by several inherent issues such as the restacking tendency of MXene sheets and low conductivity of COFs, when applied individually. Combining MXenes and COFs into heterostructures and their use as a single electrode helps in overcoming challenges for improving the energy storage capability. The current perspective intends to provide an overview of designing such COF/MXene heterostructures in the context of the energy storage applications. The research gaps that exist in designing COF/MXene heterostructures and the governing factors for improving the energy storage capability have also been highlighted as opportunities.

Combination of covalent organic frameworks (COFs) and polyoxometalates (POMs): the preparation strategy and potential application of COF–POM hybrids

“…26,27 In recent studies, scientists have thoroughly investigated the topological semimetal and higher-order topological insulator properties of COFs through quantum chemical calculations, which are important for a deeper understanding of COFs and for the design and development of their properties. 28–30 In order to expand the usage of COFs and improve their performance, they are also mixed with other materials, such as graphene, 31 carbon nanotubes, 32 metal oxides, 33 metal nanoparticles, 34 conductive polymers, 35 MOFs (metal–organic frameworks), 36 MXenes 37 and so on. Recently, POMs were introduced into COFs to construct COF–POM hybrids.…”

Exploring the feasibility of a two-dimensional layered cobalt-based coordination polymer for supercapacitor applications: effect of electrolytic cations

“…Over the past few years, graphene and other 2D materials such as MXenes, 21,22 2D covalent organic frameworks (COFs), 23 B 4 C, 24 C 3 N 4 , 25 2D coordination polymers (CPs) 26 and layered metal oxides/hydroxides 27,28 have been highly explored as supercapacitor materials. Among these materials, CPs have properties like tunable porosity, extensive surface area, and their flexibility to host a number of guest molecules and are attractive materials to be utilized for supercapacitor application.…”

Robust MOF-on-MOF heterostructures as efficient cathode candidates for next-generation supercapacitors

“…18,19 Various materials, such as 2D materials 20 (MXene, 21-23 MoS 2 , 24,25 reduced graphene oxide, 26,27 etc. ), porous materials (coordination polymer, 28,29 metal-organic frameworks (MOFs), [30][31][32][33] covalent organic frameworks, [34][35][36] etc. ), nanomaterials 37 (carbon dots, 38 transition metal oxide, 39,40 etc.…”