High capacitance and power density supercapacitor behavior in tetrameric silver nanoparticle

This study confirms the high-power and energy density EDLC-type supercapacitor activity of four-cluster silver nanoparticles. Structural, optical, and electrochemical analyses, including powder diffraction, Rietveld refinement, and Tauc’s plot, confirm their metallic nature and influence on supercapacitor performance. SEM analysis highlights the role of surface morphology in enhancing capacitance and EDX elemental analysis has been confirm the presence of AgNp as well as AgO amorphous with small Na solvent traces. AgNP were synthesized using plant extracts as reducing agents, which significantly impact their properties due to synergistic effect of AgO with AgNP. The specific capacitances of AgNP synthesized with Beta vulgaris-S1 (Fig. 5a), Syzygium Cumini-S2 (Fig. 5b), Cinnamon verum-S3 (Fig. 5c), Lawsonia inermis-S4 (Fig. 5d), Rosa Rubiginosa-S5 (Fig. 5e), and were 613 F/g, 611 F/g, 586 F/g, 149 F/g, and 123 F/g, respectively. The average value of power densities of S1 to S5 are 347 W/kg, 346 W/kg, 347 W/kg, 344 W/kg, and 365 W/kg respectively. Among these, Beta vulgaris-S1 and Syzygium Cumini-S2 exhibited specific capacitance (613, 611 F/g) and demonstrated the most favorable electrochemical behavior, with low Rs value of 1.89 and 2.65 Ω and low to moderate Rct values of 2.75 and 8.49 Ω, accompanied by Warburg contributions confirming effective ion diffusion. These findings confirm the potential of phytochemical-assisted synthesis in developing high-performance supercapacitor materials.