In Situ Generation of Electrolyte inside Pyridine‐Based Covalent Triazine Frameworks for Direct Supercapacitor Integration

Abstract

The synthesis of porous electrode materials is often linked with the generation of waste that results from extensive purification steps and low mass yield. In contrast to porous carbons, covalent triazine frameworks (CTFs) display modular properties on a molecular basis through appropriate choice of the monomer. Herein, the synthesis of a new pyridine‐based CTF material is showcased. The porosity and nitrogen‐doping are tuned by a careful choice of the reaction temperature. An in‐depth structural characterization by using Ar physisorption, X‐ray photoelectron spectroscopy, and Raman spectroscopy was conducted to give a rational explanation of the material properties. Without any purification, the samples were applied as symmetrical supercapacitors and showed a specific capacitance of 141 F g−1. Residual ZnCl2, which acted formerly as the porogen, was used directly as the electrolyte salt. Upon the addition of water, ZnCl2 was dissolved to form the aqueous electrolyte in situ. Thereby, extensive and time‐consuming washing steps could be circumvented.

Graphitic Aza‐Fused π‐Conjugated Networks: Construction, Engineering, and Task‐Specific Applications

“…[235] CTF derived from the trimerization of pyridine-3,5-dicarbonitrile (3,5-PDCN, Figure 3) had a specific capacitance of 141 F g −1 as supercapacitors without removing the ZnCl 2 catalyst, using aqueous electrolyte in situ formed upon dissolving the residual ZnCl 2 by water addition. [236] In order to make nanomaterials as good supercapacitor, TCNQ was deployed as the monomer to construct triazinelinked frameworks (TCNQ-CTFs) via the ZnCl 2 -promoted ionothermal procedure (Figure 12A). [237] Among all the CTF materials obtained from 400 to 900 °C, TCNQ-CTF-800 obtained by treating TCNQ-CTF-700 at 800 °C under N 2 demonstrated the highest specific capacitances (383 F g −1 ) and energy density (42.8 Wh kg −1 ) (Figure 12B,C).…”

“…CTF derived from the trimerization of pyridine‐3,5‐dicarbonitrile (3,5‐PDCN, Figure 3) had a specific capacitance of 141 F g −1 as supercapacitors without removing the ZnCl 2 catalyst, using aqueous electrolyte in situ formed upon dissolving the residual ZnCl 2 by water addition. [ 236 ]…”

Two‐dimensional Covalent Organic Frameworks for Electrochromic Switching

“…Recently, covalent organic frameworks (COFs), a class of crystalline porous organic polymer, have received distinct attention as alternative electrochromic materials [26–30] . COFs with well‐defined two‐dimensional (2D) or three‐dimensional (3D) framework structures have been widely applied in diverse fields starting from gas storage, separation, water purification, sensing, catalysis to energy storage [17,31–39] . Unlike MOFs, COFs are electrochemically highly stable due to the robust covalent linkages with π–π stacking structures.…”

Porous carbons derived from zinc-based nitrogen heterocyclic complexes combined with KOH activation for use as supercapacitors

“…They are widely used in many fields such as photomolecular devices, antineoplastic drugs, and supramolecular self-assembly, but there are fewer applications as electrode materials in SCs. 12 In this work, we describe the preparation of activated dipyridyl compound-derived carbons (ADCDCs) via a facile approach. Compared with the solvothermal method which usually needs a long reaction period and strict reaction conditions, the Zn-based dipyridine coordination compound is easily produced under simple stirring owing to the strong coordination ability between the N atoms in dipyridine with Zn 2+ .…”