Table 3.

Comparisons of the Major Synthesis Method

Method	Description	Typical Reaction Temp. (°C)	Reaction period	Solvent	Particle Size distribution	Particle Shape Control	Yield
Co-precipitation	Very simple, ambient conditions	20-90	Minutes	Water	Broad	Not good	High
Thermal decomposition	Complicated, inert atmosphere required	100-320	Hours to days	Organic	Very narrow	Very good	High
Microemulsion	Complicated, ambient conditions	20-50	Hours	Organic	Relatively narrow	Good	Low
Hydrothermal synthesis	Simple, requires high pressure	220	Hours to days	Water- ethanol	Very narrow	Very good	Medium