Abstract: Colloidal precursors were synthesized by precipitation method using zinc acetate(ZnAc2) and sodium hydroxide(NaOH) aqueous solution at room temperature. The products of Zn5(OH)8(Ac)2·2H2O and ZnO were prepared by controlling the pH values of the reaction system. The composition, structure, and morphology of the resultant soild were characterized by using X-ray diffraction, scanning electron microscopy and energy dispersive spectrometer. We found that when the pH value of the precursor solution was 7, a steady colloid could be synthesized by the precipitation method, and the composition of the product was Zn5(OH)8(Ac)2·2H2O after dried at room temperature. If the pH value was 14, the coagulation phenomenon occurred with the ageing of colloidal precursor, and the coagulation product was hexagonal flake ZnO. In addition, the growth mechanism of ZnO nanomaterials was discussed, and it was also considered from the effects of pH value on the stability of colloidal precursor.

Key words: ZnO, room temperature, colloidal precursor, Stabilization, flake nanomaterial, pH