In this method, hydrothermal
reaction conditions control the size and morphology of zinc oxide particles; although, in chemical methods the
reaction time is generally too long. In the previous studies of the hydrothermal syntheses of zinc oxide, reaction
procedure has been investigated. Briefly, in alkaline solution (i.e. pH 11.5) Zn(OH)4
2- ions make up the majority of
the solution species and then, this ion decompose into Zn(OH)2 at moderate temperature after calcination zinc
hydroxide decompose into zinc oxide.