Influence of incident light properties on the formation of silver nanotriangles from spherical nanoparticles

Abstract

This work investigates the role of incident light properties in the formation of silver nanotriangles from spherical nanoparticles under LED irradiation. Unlike previous studies focused on post-synthesis reshaping, this study examines the formation pathway and transformation kinetics. Silver nanospheres with an initial plasmon resonance at 403 nm were irradiated using LEDs at 387.3, 464.3, 533.7, and 628.7 nm. A clear wavelength-dependent size evolution was observed, with nanotriangle edge lengths increasing linearly with the incident wavelength. Time-resolved extinction spectroscopy revealed a progressive decrease in the spherical nanoparticle peak, accompanied by the emergence of a second peak associated with triangular nanostructures. These results indicate that plasmon-mediated energy deposition drives anisotropic restructuring via surface atom diffusion and nanoparticle coalescence, providing insight into wavelength-controlled nanoparticle synthesis.