“Enhanced supercapacitor and catalytic properties of CuMn-MOF/Ag composites for energy storage and hydrogen evolution”

Abstract

Supercapattery devices combine supercapacitors' high power density (P_d) and cycling longevity with batteries' energy density (E_d). Metal-organic frameworks (MOFs) are ideal for energy storage due to their enhanced surface area, tunable porous architecture, and structural durability. In this study, CuMn-MOF doped with Ag nanoparticles was synthesized via the hydrothermal method, which offers precise control over morphology and crystallinity. The resulting CuMn-MOF/Ag composite, characterized by XRD, SEM, XPS, and BET analysis, demonstrated well-defined crystalline structures with a high surface area. Electrochemical evaluations revealed a phenomenal capacity density (Qs) of 2800 C/g at 2.0 A/g in three-electrode systems. When employed in a supercapattery device (CuMn-MOF/Ag//AC), the composite executed a specific energy of 63 Wh/kg at a specific power of 1690 W/kg, with remarkable cycling performance, retaining 90 % of its capacity over 12,000 cycles. CuMn-MOF/Ag exhibited efficient hydrogen evolution reaction (HER) performance, with a minimal overpotential of 101.41 mV and a Tafel slope of 50.0 mV/dec. The combination of high-performance energy storage capabilities and efficient catalytic activity underscores the versatility of CuMn-MOF/Ag for applications in renewable energy systems, hydrogen production, and portable electronics.