Study Of Synthesis,Characterization And Properties Of Niobate Nanocrystals

One-dimensional niobate nanocrystals have high electro-optic coefficient and nonlinear optical coefficient,which has an important significance for the development of information 、 physical and biological science. Owing to the properties of one-dimensional nanomaterials showed anisotropism, one-dimensional nanomaterials have better performance than two-dimensional nanomaterials. However, there are many problems in the synthesis and application of one-dimensional niobate. We take a comprehensive consideration of the key issues in the theory and applications.Niobate technology research takes the lead in this paper, whose main research content is controllable synthesis, characterization, properties of one-dimensional niobate.Solved the one-dimensional niobate nanocrystalline synthesis process problem such as the middle rate is low, the morphology of uncontrolled.Maintaining the temperature is 150℃ and the alkali concentration is 10mol/L unchanged. By changing the other reaction conditions, to prepare the dendrimer and acicular potassium sodium niobate crystal. Using commercially available Nb2O5 as raw materials, K and Na in the molar ratio of 3:17 under the condition of hydrothermal reaction for 5 days, Synthesis of the diameter of 100-500 nm needle potassium sodium niobate crystal. The same with the synthesis of acicular crystals of potassium sodium niobate, using Nb2O5 nanorods as the starting material after alternative commercial Nb2O5, synthesized tree potassium sodium niobate crystal.Based on the traditional hydrothermal synthesis of KNb O3, Nb2O5 nanorods and KNb3O8 nanorods were used as raw materials and template to replace the traditional method using commercially available Nb2O5, synthesized diameters of 100-200 nm and 100-150 nm of KNb O3 nanorods. The use of Nb2O5 nanorod synthesis crystallization degree relatively complete KNb O3 nanorods need 5d, and the use of KNb3O8 nanorods, just 12 h can synthesize pure phase KNb O3 nanorods, greatly shortening the reaction time. Similarly, on the basis of traditional hydrothermal preparation of Na Nb O3, Nb2O5 as a raw material and templates nanorods synthesized500-800 nm in diameter nanorods Na Nb O3. When using niobium powder as raw reaction synthesized a diameter of 50-150 nm of Na Nb O3 nanorods, which greatly reduced the product Na Nb O3 nanorods particle size.On the basis of traditional KNb3O8 prepared molten salt method, if add appropriate amount in the powder of the raw material of Nb2O5 nanorod, the particle size of 150-500 nm KNb3O8 nanorods can be synthesized, which greatly reduce the diameter of the product. The diameter of 30 to 50 nm nano silver particles through the silver mirror reaction attached to KNb3O8 nanorods, the fluorescence properties performance of the KNb3O8 nanorods were greatly enhanced after silver nanoparticles plated,Fluorescence intensity increased by 4 fold. Meanwhile, the photocatalytic efficiency of KNb3O8 nanorods greatly improved after silver nanoparticles plated,photocatalytic efficiency increased by 2 fold. The intensity of KNb3O8 nanorods and KNb O3 nanorods second harmonic signal changed obviously with the rotation of the polaroid. Experimental prepared KNb3O8 nanorods and KNb O3 nanorods have strong nonlinear optical properties.