Modulating composite colloidal particle morphology by reaction kinetics in seeded-growth

This article presents a systematic investigation into the seed-mediated growth of composite colloidal particles, illustrating a range of controlled sizes and morphologies. We developed a facile approach to modulate the morphology of composite particles in seeded-growth by varying the solvent composition during the growth of TiO₂ and SiO₂colloidal particles. Core–shell type morphologies were observed during the growth of inert nanoparticles on active seed surfaces. In contrast, active nanoparticles facilitated the growth of anisotropic nanoparticles. Our experiments also demonstrated that the growth size of nanoparticles could be tuned by altering the concentration of precursors. We obtained two types of nanoparticles with distinct sizes: larger particles and smaller ones, with the latter originating from secondary formation. The variety of morphologies observed in seed nanoparticles confirms the applicability of our hypothesis on seeded growth.