Biogenic AgNPs: Integrated Evaluation of Their Antibacterial Efficacy, Photocatalytic Degradation Capability, Optical Features, and Electrical Transport Mechanisms

Abstract

A comprehensive evaluation of silver nanoparticles (AgNPs) synthesized through an eco‐friendly, plant‐mediated method is represented. It delivers a rare, single‐system multifunctional evaluation correlating structural, optical band‐gap, biological, photocatalytic, and detailed electrical transport mechanisms within a unified biogenic AgNP configuration. The AgNPs, prepared at three concentrations (NP1, NP2, NP3), were tested against Staphylococcus aureus and Escherichia coli . The nanoparticles showed clear antibacterial activity, with E. coli exhibiting higher susceptibility due to its thinner peptidoglycan layer. Photocatalytic experiments revealed that the nanoparticles efficiently degraded methyl orange (MO) and tetracycline (TC) under visible light, achieving degradation efficiencies of approximately 85% and 88%, respectively. Kinetic modelling confirmed pseudo–first‐order reaction behaviour. Optical characterization through UV‐Visible spectroscopy indicated well‐defined surface plasmon resonance (SPR) peaks and size‐dependent band gaps ranging from 2.99 to 3.10 eV. Additional analyses of Urbach energy (E U ), refractive index, and spectral broadening highlighted differences in structural order and nanoparticle stability. Electrical transport measurements demonstrated semiconducting characteristics governed by Mott variable range hopping in dc mode and correlated barrier hopping (CBH) in ac mode, with temperature and magnetic field significantly influencing conductivity. Collectively, the results show that green‐synthesized AgNPs possess a combination of strong antibacterial action, high photocatalytic efficiency, tunable optical features, and disorder‐dependent charge transport.