A Molecular Pillar Approach To Grow Vertical Covalent Organic Framework Nanosheets on Graphene: Hybrid Materials for Energy Storage

Abstract

Hybrid 2D-2D materials composed of perpendicularly oriented covalent organic frameworks (COFs) and graphene were prepared and tested for energy storage applications. Diboronic acid molecules covalently attached to graphene oxide (GO) were used as nucleation sites for directing vertical growth of COF-1 nanosheets (v-COF-GO). The hybrid material has a forest of COF-1 nanosheets with a thickness of 3 to 15 nm in edge-on orientation relative to GO. The reaction performed without molecular pillars resulted in uncontrollable growth of thick COF-1 platelets parallel to the surface of GO. The v-COF-GO was converted into a conductive carbon material preserving the nanostructure of precursor with ultrathin porous carbon nanosheets grafted to graphene in edge-on orientation. It was demonstrated as a high-performance electrode material for supercapacitors. The molecular pillar approach can be used for preparation of many other 2D-2D materials with control of their relative orientation.

A Microporous Covalent–Organic Framework with Abundant Accessible Carbonyl Groups for Lithium‐Ion Batteries

“…[5,6] This usually incurs agglomeration of polymer chains,a nd results in poor access of redoxactive groups by Li + or electrons,w hich are essential for electrochemical reactions,and hence low utilization efficiency of less than 70 %ofthe polymers,e specially at high rates. [9][10][11] Structuring microporous polymer framework electrodes with both facile Li + diffusion and electron transport is of crucial importance for organic LIBs. [9][10][11] Structuring microporous polymer framework electrodes with both facile Li + diffusion and electron transport is of crucial importance for organic LIBs.…”

“…[7,8] Microporous polymers with two-or three-dimensional (2D or 3D) frameworks and controllable pore size favor permeation of aprotic electrolyte and diffusion of ions. [9][10][11] Structuring microporous polymer framework electrodes with both facile Li + diffusion and electron transport is of crucial importance for organic LIBs.…”

Covalent Organic Frameworks: A New Class of Porous Organic Frameworks for Supercapacitor Electrodes

“…with oriented COF‐1 nanosheets grafted on the surface of graphene oxide (GO) perpendicularly. Furthermore, the v‐COF‐GO was converted into the boron doped carbon material owning the nanostructure of the precursor, and the carbon material could be applied in supercapacitor as a high‐performance electrode . Preparation process was showed in Figure , in which benzene‐1,4‐diboronic acid (DBA) was anchored on the surface of GO covalently, and used as nucleation sites for growing ultrathin 2D COF‐1 nanosheets on the surface of GO directly.…”

Interfacial Synthesis of a Monolayered Fluorescent Two‐Dimensional Polymer through Dynamic Imine Chemistry

“…Two-dimensional polymers (2DPs) have been generally accepted as materials with atomic-thick or monolayer, covalently linked, highly ordered 2D topological network. [1][2][3][4][5][6][7][8] The recent high interest and the fast development of 2DPs materials are driven by their unique structures, [9][10][11] potential applications [12][13][14][15][16] and infinite structure possibilities through monomer design. [17] The properties of the 2DPs are completely different from those of traditional linear or branched polymers due to the total different 2D structure.…”