Effects of aging conditions on the morphologies of ZnO particles synthesized under hydrothermal conditions from layered zinc hydroxide as a precursor derivered from zinc acetate

Abstract

Zinc oxide is a useful material for various products. ZnO crystals usually grow in the c-axis direction, on the less exposed (001) plane. However, the (001) plane has high chemical reactivity, and plate-like ZnO crystals on large (001) planes have superior UV-lasing and other properties. In this study, layered zinc hydroxide acetate (ZHA), a precursor of ZnO, was aged in deionized water and Zn(OCOCH 3) 2 or CH 3 COONa aqueous solutions of various concentrations under hydrothermal conditions at 90 and 120°C. Aging at above 90°C yielded ZnO in all the solutions, and the concentrations of the CH 3 COONa aqueous solutions did not affect the form of the ZnO particles. On the other hand, when ZHA was aged in Zn(OCOCH 3) 2 aqueous solution, the crystal growth of ZnO in the c-axis direction was suppressed as the Zn(OCOCH 3) 2 concentration increased. In the case of aging in 1 molL −1 Zn(OCOCH 3) 2 aqueous solution, plate-like ZnO was obtained, but the yield was about 10% and a large amount of ZHA remained. When the obtained mixture of plate-like ZnO and ZHA was aged again in deionized water at 90 and 120°C after washing, most of the ZHA was transformed into plate-like ZnO after aging for over 72 hours.

Influence of the Alcohols on the ZnO Synthesis and Its Properties: The Photocatalytic and Antimicrobial Activities

“…As the reactants include only the zinc acetate and the corresponding alcohol, the expected products are ZnO nanoparticles and eventually Zn(OH) 2 and unreacted zinc acetate, together with polymeric intermediate species like Zn 5 (OH) 8 (CH 3 OO) 2 or Zn 5 (CO 3 ) 2 (OH) 6 [10,[84][85][86]. For the samples obtained in the C1-C6 alcohols, the thermal analysis results are presented in Figure 1.…”