Colloidal nanocrystals solution-phase

The most successful NQD preparations with respect to nanocrystal quality and monodispersity entail pyrolysis of metal-organic precursors in hot coordinating solvents (120 360 °C). Understood in terms of La Mer and Dinegar s studies of colloidal particle nucleation and growth, these preparative routes involve a temporally discrete nucleation event followed by relatively rapid growth from solution-phase monomers and finally slower growth by Ostwald... 

Colloids of alloys have been made by the chemical reduction of the appropriate salt mixture in the solution phase. Thus, Ag-Pd and Cu-Pd colloids of varying composition have been prepared by alcohol reduction of mixtures of silver nitrate or copper oxide with palladium oxide (Vasan and Rao 1995). Fe-Pt alloy nanocrystals have been made by thermal decomposition of the Fe and Pt acetylac-etonates in high-boiling organic solvents (Sun et al. 2000). Au-Ag alloy nanocrystals have been made by co-reduction of silver nitrate and chloroauric acid with sodium borohydride (Sandhyarani et al. 2000 He et al. 2002). 

As an alternative to in situ growth, nanocrystals can be synthesized either in solution (e.g. by colloidal synthesis) or in the gas phase, prior to dispersion in a matrix or deposition or self-assembly onto a substrate. 

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