Hierarchical nanocomposites of redox covalent organic frameworks nanowires anchored on graphene sheets for super stability supercapacitor

Covalent organic frameworks (COFs) have shown significant potential as ideal electrode materials for supercapacitors (SCs) due to their highly accessible surface areas and tunable active sites. However, their poor electrochemical properties hinder their application prospects in electrochemical energy storage devices. Herein, we successfully synthesized two-dimensional COF (TpPa-(OH)2) nanowires anchored on the surface of reduced graphene oxide (TpPa-(OH)2/rGO) using a facile hydrothermal method in aqueous solution. The anchored COFs nanowires effectively prevent graphene sheets from stacking, thereby enhancing the electronic double layer capacitor of rGO and introducing pseudo-capacitance contributed by the redox COFs. Additionally, rGO's inherent conductivity facilitates electron transfer and ion migration, improving electrochemical properties. By regulating the content ratio of graphene and COF, the optimal TpPa-(OH)2/rGO shows obvious COFs nanowires structure anchored on graphene sheets and exhibits exceptional electrochemical performance, with a high specific capacitance of 371.1F/g at 0.5 A/g and excellent cycle stability of 93 % after 20,000 cycles at 10 A/g. Furthermore, we assembled symmetric SCs (SSCs) using TpPa-(OH)2/rGO-3, achieving a specific capacitance of 197.1F/g at 0.2 A/g and delivering a maximum energy density of 16.6 Wh/kg at a power density of 158.7 W/kg. These results unambiguously indicate the significant potential of TpPa-(OH)2/rGO as a high-performance electrode material in energy-storage devices