Functional nanoparticles from chemically coupled precipitation processes

Abstract

Coupled chemical reactions are known to produce ordered patterns under certain conditions far from thermodynamic equilibrium. Such phenomena can be exploited to obtain complex mineral structures, as reported for self-assembled composites of crystalline carbonates and amorphous silica. In the present work, we show that the dynamic pH-based coupling underlying the formation of these inorganic composites can be extended to produce core-shell nanostructures of functional materials. Specifically, the concept was applied to synthesize fluorescent silica-coated quantum dots in a simple one-pot procedure at ambient conditions based on the coupled co-precipitation of metal chalcogenides and silicate. This straightforward approach can likely be generalized to produce a broad variety of functional nanoparticles with possible applications in the areas of optics, energy storage, catalysis, and beyond.