Controllable Preparation And Property Research Of Rare Earth Phosphate Micro Nanomaterials By Redox Hydrothemal Synthesis

Rare earth compounds have many special properties, because of rare earth elements'the 4f electron express character. Cerium phosphate with excellent physical and chemical performance of these, has been extensively used in fluorescent material, ion exchanger, catalytic materials, plastic ceramic composite materials nuclear waste disposal and so on. Because its performance is closely related with the crystal morphology, to achieve controlled morphology of cerium phosphate and research on corresponding property changes is the focus of cerium phosphate material research.In this paper, tetravalent cerium salt and phosphoric acid as raw materials, by redox hydrothermal synthesis, we obtained a series of hexagonal phase cerium phosphate spherical powders with a adjustable size range from nanometer to micrometer, and Eu, Dy-doped cerium phosphate microspheres. The changes in morphology and fluorescent properties, doped cerium phosphate microspheres fluorescence properties, and mechanism of redox hydrothermal synthesis are researched.Main tasks are as follows:Using ceric sulfate as cerium source, ethanol as reducing agent, tributylamine as the nucleophile dispersant, P123 as surfactant, phosphoric acid as mineralizer at 150℃, only by a dynamic mixing 4h Hydrothermal regulate the concentration of reactants, synthesis of a series of particle size measurements by the 50nm-1.5μm change hexagonal phase cerium phosphate spherical powder. By Parallel experiments showed that Tributylamine, hydrothermal processes are conducive to uniform mixing and avoid grain nucleation over growth of hydrothermal time to extend the lead to grain growth. This series of cerium phosphate products have a wavelength of 200-330nm spectral band and the continuous excitation wavelength 385nm and emission spectrum, with the growth in product size, intensity of emission spectrum of basic enhancement to the product particle size 200nm emission peak intensity maximum, FWHM only 20nm, particle size to nanometer range, appeared red-shifted emission spectra, excitation spectra blue shift.Ceric sulfate as the cerium source, ethanol as a reductant, P123 as surfactant, phosphoric acid as mineralizer, europium oxide and dysprosium oxide doped rare earth ion source, through the static hydrothermal reaction at 150℃24h, obtained morphology rules CePO4:EuDy microsphere products microsphere surface aligned with a thickness of 20nm, about 50nm nano-layer spacing array. Fluorescence analysis showed that cerium phosphate matrix absorption of light energy of a successful transfer to the activation of ion Eu3+ and Dy3+, Ce3+ the fluorescence quenching, has been fired red violet 3 shade of fluorescent material, which is mixed with Eu3+ and Dy3+ by 2.5% of cerium phosphate products Ce3+ energy transfer is the best.Through a series of selected comparative study found the key factor of the redox hydrothermal synthesis of cerium phosphate sphere powders are the ethanol on instantaneous reduction of tetravalent cerium, producing a large number of cerium phosphate nuclei, in P123 micelle formation of spherical micro-reactor, the grain growth is limited, and powder products are spherical. The surface elemental analysis shows that this method can completely transform tetravalent Ce into trivalent Ce, and uniform morphology of cerium phosphate samples synthesized.