Synthesis and growth mechanism of various structures Bi2O3 via chemical precipitate method

Due to dielectric permittivity, significant band gap and photo-catalytic activity, Bi2O3 has many potential applications in functional material field. Its special properties are determined by the morphology and crystal phase. In this study, the tetrahedron, rod-like and flowerlike Bi2O3 powders with alpha and gamma phase were synthesized by chemical precipitation method and the effect of the reaction conditions was studied. The model was designed to illustrate this process. Phase composition, microstructure, and morphology of the powders were investigated by X-ray diffraction and field emission scanning electron microscope. The results suggested that the phases and morphologies of Bi2O3 powders were influenced by the surfactant, reaction rate and reactant adding order of the experiment when Bi2O3 were synthesized by chemical precipitation method. The mechanism was related with the free energy of the crystal face and the condition of the interface between crystal and liquid phase, which induced the different crystal growth mechanism during the reaction. The results indicated a controlled way to design various Bi2O3 for applications.