| Nano borates play extremely important application in strengthen of composite materials such as lubricant oil, metal and fire retardant and in luminescent materials in the future. In practical application, their performances are often affected by nanomaterials structure and morphology. Therefore,considerable attentions have been devoted to the fabrication of nano-structured borates.This thesis is focused on the fabrication of different figures of nickel borate and Lanthanum borate via sol-gel process and solid-state precursor method. The structure and morphology of the resulting products have been characterized by XRD, SEM, TEM and HRTEM, while the spectra properties of the products have been investigated by FT-IR spectrometer and fluorescence spectrometer. The main contents are summarized as follows:1. Nickel borate (Ni3(BO3)2) nanorods are synthesized by the sol-gel method using nickel nitrate and boric acid as reactants , citric acid as the foaming reagent. The length and diameter of the nanorods are controlled by calcination temperature and the molar ratio of Ni(NO3)2/H3BO3. The diameter of the nanorods is in the range of 200300 nm and the length is in the range of 23μm with n(Ni(NO3)2)/n(H3BO3) of 1:3. Besides, the role of the citric acid in the growth of nanorods is discussed, and the results show that the reaction of citric acid and nickel ions will form coordination compound in mesh structure, thus prompts even dispersion of nickel between the grid and providing favorable response space for the formation of nickel borate nanorod. 2. Nickel borate (Ni3(BO3)2) are synthesized by solid-state precursor method using nickel nitrate and boric acid as reactants , citric acid and oxalic acid as the ligand. The results indicate that the as-prepared products are orthorhombic Ni3(BO3)2 which is the same as the products synthesiszed via the sol-gel method. The figures of nickel borate with the oxalic acid are better than those with the citric acid as ligand. The diameter of the nanorods is in the range of 300400 nm and the length is in the range of 34μm with n(H2C2O4)/n(Ni(NO3)2) of 2:1.3. LaBO3 and Eu3+ doped LaBO3 nanoparticles are synthesized via sol-gel method, using H3BO3, La(NO3)3·6H2O, C6H8O7·H2O and Eu2O3 as starting materials. The results indicate that as-prepared products are crystallized in pure body centered orthorhombic LaBO3 phase with uniform spherical morphologies and the sizes of the samples are in the range of 80100 nm. XRD patterns of the as-fabricated Eu3+-doped LaBO3 nanoparticles show that Eu3+ is doped at La3+ sites in LaBO3 crystal. Fluorescence spectrum of LaBO3: Eu3+ nanoparticles indicates that and the as-prepared LaBO3: Eu3+ nanoparticles show strong and stable fluorescent intensity. It can be expected that the LaBO3:Eu3+ nanoparticles have potential applications in electroluminescent devices , integrated optics,biological labels and so on. |
