2024 年 65 巻 4 号 p. 405-413
ZnO is synthesized by aging layered zinc hydroxide acetate, ZHA, as a precursor. The effects of type and concentration of alkaline earth metal ions on the crystal growth of ZnO were studied by synthesizing ZnO by aging ZHA in calcium acetate (CaAc), strontium acetate (SrAc), and barium acetate (BaAc) aqueous solutions at various concentrations. In all cases, ZnO particles elongated in the c-axis direction were obtained, and the aspect ratio increased with increasing ion concentration. Especially, in BaAc solution, the longest particles in the c-axis direction were observed. This is due to the small hydration ionic radius of barium, which is easily adsorbed on the side of ZnO. When aging ZHA in 2.0 mol/L of BaAc solution, agglomerated particles were formed in the early stage of aging, and the growth of individual particles in the agglomerate and entire agglomerated particles proceeded in parallel, resulting in particles with characteristic bouquet-shapes. In conclusion, the c-axis growth of ZnO is controlled by the type and concentration of alkaline earth metal ions.
