Kinetic Modeling and Optical Property Evolution of Silver Nanoparticles from Water Hyacinth: A Simulation Approach Using Mie-Drude and Quantum Confinement Theories

The synthesis and optical properties of silver nanoparticles (AgNPs) derived from water hyacinth were modeled using a computational framework integrating reduction kinetics, particle size distribution, and quantum confinement theory. The reduction followed pseudo-first-order kinetics, with Ag⁰ concentration rising to ~997 µM in 120 minutes. Simulated nanoparticles exhibited a lognormal size distribution (40-100 nm, dispersity index 0.08). UV-Vis spectra showed surface plasmon resonance peaks shifting from 392 to 421 nm as particle size increased, with absorbance rising from 0.21 to 2.25 A.U. Bandgap energies decreased from 3.12 to 3.07 eV with growth, indicating reduced confinement. Temperature-dependent modeling (25-125°C) revealed faster Ag⁺ reduction and broader distributions at higher temperatures. These results demonstrate how computational modeling can predict and optimize nanoparticle synthesis to achieve desired plasmonic and electronic properties for catalytic, sensing, and photonic applications.