Molecular level tuning of redox active 2d covalent organic frameworks for energy storage

Abstract

Covalent Organic Frameworks COFs offer a dynamic platform to play with its chemical functionalities as well as with it 8217 s the structure and symmetry The choice of symmetry of the building units drives the propagation the COFs either in a two dimensional way or in three dimensional way The 2D network of the COFs when decorated with multiple redox active functional groups it resembles like heteroatom doped graphite structure Additionally the presence of one dimensional porous nano channel inside the 2D layered structure of COFs opens up the possibility for grafting the nano wall with electron rich light elements Along with the interlayer 61552 61552 stacking like graphite these 2D COFs gain its extra stability from inter and intralayer hydrogen bonding The plausible tunability of the building units and variation of the redox segments of the 2D COFs bring the attention for utilising it as electrode materials in the energy storage system hence to find out a suitable alternative of graphitic materials with lot more advantage in terms of durability and performance Hereby the designed way we developed the Nitrogen and Oxygen rich 2D COFs since these two lightweight atoms are already known to interact with electro positive charge carriers Li Na and H Whenever these atoms are introduced into the frameworks in terms of redox active functional groups these COFs start acting as an apt candidate for energy storage in Metal ion battery and in supercapacitors The scope of synthetic development of desired building monomers aids to enhance the number of redox centres per unit of the 2D COFs As a result systematic improvement of the performance of the LIB SIB and supercapacitors were possible Moreover structure property co relation to explain the mechanistic pathway has been properly investigated in both experimental and theoretical way The advantage of the inherent surface area of COFs and enhanced surface accessibility of COF derived Covalent Organic Nanosheets CONs assist to understand the double layer capaci newline newline