EARTH

[3913-23-10] Synthesis of Zn composite oxide using Zn-Al composite hydroxide as a precursor and its particle shape control

○Kohei Yamazaki¹, Mitsuaki Matsuoka¹, Norihiro Murayama¹, Toru Maruyama¹ (1. Kansai University)

Chairman: Carlito Tabelin （Hokkaido University）

Keywords:Zn composite hydroxide, Zn complex oxide, Wet process

Zn oxide has a large band gap and is used as a photocatalyst and a fluorescent substance. It is important to control the particle shape according to the application. A change in the band gap of resulting products appears by adding Al ions to Zn oxide. A solid phase method is usually used for synthesis of a complex oxide. However, sintering at high temperature should be required due to the reaction in the solid phase. In addition, it is difficult to control the particle shape because of high temperature. By using Zn-Al composite hydroxide as a precursor, it is possible that a composite oxide will be formed at lower temperature because the metal ions in a precursor are mixed at the ion level.
Zn composite oxides were synthesized using Zn-Al composite hydroxides as a precursor in this study. The particle shape and the light absorption characteristics of various Zn composite oxides were investigated. Crystallinity of Zn-Al composite hydroxides as a precursor was improved by applying a hydrothermal treatment. By calcining the precursors after the hydrothermal treatment, the oxides reflecting the particle shape of precursor was formed. It was considered that the crystal structure of precursor was strengthened by the hydrothermal treatment. The light absorption characteristics of the oxides were different with or without the hydrothermal treatment to precursors, suggesting the change in the crystal structure of products. It was found that the particle shape and the light absorption characteristics could be controlled by applying the suitable synthesis condition of precursor and the preferable hydrothermal treatment as a pretreatment.