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

Abstract

The biological green synthesis of silver nanoparticles (AgNPs) has attracted considerable attention due to its sustainability and potential applications in biomedical and technological fields. In this study, AgNPs synthesized using Artemisia lerchiana Weber extract were systematically compared and characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, and thermogravimetric–differential thermal analyses. The electrochemical performance of A. lerchiana–derived AgNP-based electrode materials was investigated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a 1 M Na₂SO₄ aqueous electrolyte. The CV results showed that the electrodes exhibited predominantly capacitive behavior with notable pseudocapacitive contributions, achieving a maximum specific capacitance of 239.07 F·g⁻¹ at a scan rate of 5 mV·s⁻¹. GCD tests confirmed excellent charge–discharge reversibility, with the highest capacitance value recorded at a current density of 0.07 A·g⁻¹, reaching 322.14 F·g⁻¹. Long-term cycling over 5000 charge–discharge cycles showed minimal degradation and preserved capacitive properties, indicating high electrochemical durability. EIS analysis revealed low charge-transfer resistance and favorable ion-diffusion kinetics, reflecting the high electrical conductivity and ion-accessible architecture of the A. lerchiana AgNP composite. These results demonstrate that A. lerchiana–derived AgNP electrodes combine high energy-storage capacity, fast charge–discharge capability, and long-term stability, making them promising candidates for advanced supercapacitor applications.