The Preparation And Mechanism Of Zinc Oxide Of Different Morphologies By The Method Of Boiling Reflux

Ultrafme zinc oxide is a kind of new high-functional inorganic product facing the 21th century. Zinc oxide is applied in chemical industry, electron, biology and mechanical fields etc. In recent years, with the further research and function of zinc oxide powder, the utilization field of zinc oxide becomes even wider than before, among which the utilization of UV protection, photo catalyst, and conduction zinc oxide has become important motivation of the industrial development of ultrafine zinc oxide.Many preparation methods of zinc oxide have been studied including gas-phase method, liquid-phase method and solid-phase method up to now. Liquid-phase method includes sol-gel method, alkoxide hydrolysis method, precipitation method and hydrothermal method etc. Because of many advantages such as high purity, controlled morphology, uniform composition, liquid-phase method is a kind of method having great prospect. But most preparation methods have deficiencies by the complicated technology, harshterms and high producing cost, so a new method------boiling reflux method isstudied in this paper. This method has many virtures such as simple technology, mild conditions and fast phase-transformation. Furthermore, by controlling conditions of crystal growth (pH, additives, concentration of additives and anion, inorganic salts, mixing speed etc.) spherical, rod-like, olive-like, hexagonal prism and slice zinc oxide have been prepared.Polar growth and mechanism of ZnO crystal under boiling reflux conditions is studied in this paper based on Anion Coordination Polyhedron Growth Unity Theory, our studying result is accorded in the result by hydrothermal method. Comparing this method, boiling reflux method is more advisable.The mechanism is also analyzed. The results indicated that the growth unit is Zn(OH)2(H2O)2 under the condition of neutral solution and Zn(OH)4 under the condition of mildbase solution. Result of long-rod-like zinc oxide is obtained that cannot be explained by Anion Coordination Polyhedron Growth Unity Theory. But an appropriate explanation is found by another aspect of supersaturation.