Bioinspired silver nanoparticles from Artemisia lerchiana as durable electrodes for next-generation supercapacitors

A novel, eco-friendly approach for synthesizing silver nanoparticles (AgNPs) using Artemisia lerchiana extract is presented, where plant-derived biomolecules act as natural reducing and stabilizing agents. The biosynthesized AgNPs exhibit uniform spherical morphology with sizes of 25-50 nm, high crystallinity confirmed by X-ray diffraction (XRD), elemental purity verified by energy-dispersive X-ray spectroscopy (EDX), characteristic functional groups identified by Fourier-transform infrared spectroscopy (FTIR), surface morphology characterized by scanning electron microscopy (SEM), and excellent thermal stability demonstrated by thermogravimetric analysis (TGA). Electrochemical evaluation demonstrated pronounced pseudocapacitive behavior, with a maximum specific capacitance of 322.14 F g^-1 at 0.07 A g^-1, 89.25% capacitance retention after 5000 cycles, an energy density of 4.74 Wh kg^-1, and a power density of 336.76 W kg^-1. Electrochemical impedance spectroscopy (EIS) analysis indicated relatively low series resistance (41.2 Ω) and charge-transfer resistance (11.7 kΩ), confirming efficient ion diffusion and favorable electrode-electrolyte interactions. This green synthesis strategy provides a cost-effective and sustainable route for producing structurally robust and electrochemically active supercapacitor electrodes, demonstrating the potential of combining plant biochemistry with nanotechnology for the development of environmentally benign energy-storage materials.