In general synthesis method should be reproducible, should produce a perfect monodisperse nanoparticles and should be easy and cheap. The chemical methods are either based on the kinetic control of nucleation and growth of the particles on electrostatic stabilization in (aqueous) suspension, or on the introduction of spatial constraints. The latter include particle formation within or at the interface of micelles, vesicles, or bilayer lipid membranes, surface monolayer and Longmuir Blodgett films, within the channels of zeolites, in interlayer of clay, in peptides, or in biological cells.
Synthesis of ZnS nanoparticles

An usual method of synthesis for zincsulfide particles involves the reaction of Zn2+-ions with a sulfide (S2-) source i.e. H2S (Hydrogensulfide) or Na2S (Sodiumsulfide). ZnS forms instantenously at a certain pH value. The ZnS powder obtained consists of particles with a very large shape and size distribution.

Method of precipitation from homogeneous solution

Thiacetamide is used as a sulfide source. When it hydrolyses, the equilibrium is shifted by a change in temperature, concentration and pressure. When they have reacted with Zn2+ to form zincsulfide the available sulfide ions are no longer present in the reaction solution and new sulfide ions are released by the thioacetamide.