An Application of The Thermodynamic Approach to Explain the Shape Selection During Light-Induced Growth of Silver Nanoparticles

Synthesis of silver nanoparticles of different shapes and sizes by the chemical reduction of Ag+ may be strongly influenced by the light irradiation. A key question is understanding the mechanism underlying the transformation of initial spherical seeds into prisms and decahedra under visible light. In this study, we summarize existing theories of light-induced nanoparticle growth and apply a thermodynamic approach to shape selection during the synthesis of silver nanoparticles. We propose a universal thermodynamic model that explains both the influence of light on the synthesis and transformation of silver nanoparticles in the presence of H2O2. This model accounts for the shift of the chemical potential relative to interfacial energies and the monoatomic step energies on the {111} facets. Our results demonstrate that the morphology of silver nanoparticles is determined primarily by photon energy rather than by the chemical nature of the reagents.