A preliminary study on the hydrothermal synthesis of layered cobalt oxides

Layered sodium cobalt oxide is an attractive magnetic material for thermoelectric applications. The Seebeck coefficent of this material exceeds unity and it shows different types of magnetic behaviour depending on the Na content in NaxCoO2. A preliminary study is elaborated for obtaining the layered sodium cobalt oxide materials by hydrothermal synthesis method. In order to discover conditions for the hydrothermal synthesis of NaxCoO2 phase, we studied the influence of the concentration mineralizer, the temperature, the reaction time and Co(OH)(2) concentration in the formation of desired phase, NaxCoO2 phase. From these results, it is encouraging that NaxCoO2 pure phase is possibly produced if suitable experimental conditions are chosen. The low temperature and pressure synthesis conditions propose the hydrothermal method that a facile and cheaper preparation method of layered sodium cobalt oxide.