Optimization of FeMn-MOF doped with silver nanoparticles for high-performance supercapattery devices

Supercapacitors are demanded by energy storage devices for both fast charging and discharging performance as well as extended life cycles. The design and manufacture of higher supercapacitor electrodes help a device to function much better. Ag nanoparticles were produced on Fe-MOF and Mn-MOF using the hydrothermal synthesis technique to synthesize unique composite material called FeMn-MOF/Ag (NPs). These refined composites find use in supercapacitors, hydrogen evolution reactions (HER), and electrochemical sensors. Highly conductive silver nanoparticles were added to FeMn-MOF with high rate capability. Apart from their inherent benefits of metal-organic frameworks, the as-made FeMn-MOF/Ag nanoparticles also improved electrical conductivity. When the scan rate was 3 mV s⁻¹, the FeMn-MOF/Ag (NPs) showed a specific capacity (CV) of 1417 C g⁻¹. Similarly, when the applied current density was 2 A g⁻¹, it displayed a specific capacity (GCD) of 2346 C g⁻¹. The FeMn-MOF/Ag (NPs)//AC asymmetric supercapacitor exhibited an energy density of 13 (Wh/kg) and a power density of 1685 (W/kg). For the hydrogen evolution process, the material exhibited an overpotential of 90.22 mV and a Tafel slope of 58.4 mV dec⁻¹. Furthermore, it exhibited exceptional durability in cycling, maintaining 93.3% of its capacitance after undergoing 12,000 cycles. Therefore, these results offer crucial insights into the progress of different electrode materials. The results suggest that FeMn-MOF/Ag nanoparticles possess advantageous characteristics suitable for utilization as electrodes in supercapattery and HER (hydrogen evolution reaction) applications.