Synthesis of COF-300/ReSe₂ heterostructure with synergistic interfaces for enhanced energy storage systems and hydrogen evolution reaction

This study explores a novel supercapacitor system utilizing activated carbon (AC) as the anode and COF-300/ReSe₂ as the cathode, demonstrating an innovative approach to high-performance energy storage. The COF-300/ReSe₂ composite was synthesized via a hydrothermal method and exhibits remarkable electrochemical properties due to its enhanced crystallinity, high porosity, and strong framework conjugation. The COF-300/ReSe₂-based device delivers a specific capacity of 185 C/g at 1.0 A g⁻¹, an energy density of 180 Wh kg⁻¹, and a power density of 1600 W kg⁻¹ at 1.0 Ag^-1. It also maintains excellent stability, retaining 86.9 % of its capacity and 90.3 % columbic efficiency after 1000 charge–discharge cycles. As a standalone electrode, COF-300/ReSe₂ achieves a high specific capacity of 1471 Cg^-1 at 1.0 Ag^-1. In addition to energy storage, the composite shows outstanding catalytic performance for the hydrogen evolution reaction (HER), with a low Tafel slope of 67.72 mV dec⁻¹ and an overpotential of 126.73 mV. These results confirm the potential of COF-300/ReSe₂ as a multifunctional material for both energy storage and HER applications.