Triazine-Based Two-Dimensional Porous Covalent Organic Framework for Efficient Electrode Materials for Electrocatalytic Hydrogen Generation and Hybrid Supercapacitors

Abstract

The urgent need for eco-friendly and sustainable energy storage systems or green energy production methods to combat the detrimental effects of non-renewable fossil fuels is widely recognized. In this context, we have synthesized a pyromellitic diimide and triazine-containing covalent organic framework named PDT-COF and investigated its performance in two key energy applications: electrocatalytic hydrogen evolution reaction (HER) for green hydrogen energy production and electrochemical energy storage for supercapacitor devices. The PDT-COF nanosheets exhibit a high surface area of 312.6 m 2 /g and abundant pores with a size of ∼1.8 nm. Leveraging these features, the metal-free PDT-COF electrocatalyst demonstrates good performance in HER, requiring a minimal overpotential of 210 mV for 10 mA/cm 2 current density. Notably, PDT-COF follows the Heyrovsky−Volmer mechanism for HER and exhibits outstanding durability, sustaining over 60 h of continuous electrocatalysis. Furthermore, the PDT-COF-based asymmetric solid-state device exhibits a specific capacitance of 104 F/g, coupled with a high energy density of 32.55 W h/kg and a power density of 1875 W/kg at a current density of 1 A/g. Importantly, the robustness and cycle stability of the PDT-COF-based asymmetric pseudocapacitor device are confirmed, as it retains 88% of its initial capacitance and maintains a Columbic efficiency of 90% even after 5000 cycles of charge and discharge. Considering these findings, the synthesized PDT-COF material holds great promise as a metal-free electrode material for future applications in hydrogen energy generation and electrochemical energy storage devices.

Generation of covalent organic framework-derived porous N-doped carbon nanosheets for highly efficient electrocatalytic hydrogen evolution

“…S8 in ESI †. 51–53 The FE of TP-COF-C700 was calculated as 98%, which was very close to the ideal value of 100%.…”