A kind of preparation method of Nano material of lead tungstate
Technical field
The invention belongs to technical field of inorganic nanometer material, be specifically related to a kind of preparation method of Nano material of lead tungstate.
Background technology
In recent years, along with the development of high energy physics, find that PbWO4 (PWO) crystal has special advantage in exploring novel scintillator, it has high-density (8.3g/cm especially
3), short irradiation length (0.89cm), fast luminescence decay time (90% luminescence decay time is less than 20ns) and lower-price characteristic and be elected to be compact type IU meson spiral detector in the Large Hadron Collider (LHC) (compact muon solenoid, core component electromagnetic calorimeter scintillator material CMS) by CERN.
Crystal of lead tungstate has caused people's concern widely owing to its characteristics of luminescence and potential using value as a kind of luminescent material.There are some researches show that under certain excitation wavelength, crystal of lead tungstate shows the band absorption of blueness, green, redness, but its research is mainly concentrated on the crystal aspect, but relatively more rare to the research of its preparation and performance.
Hydrothermal method is as a kind of main method of preparation nano material, its principle is in special closed reaction vessel (autoclave) lining, adopt the aqueous solution as reaction medium, by reaction vessel is heated, create a high temperature, reaction under high pressure environment, make common indissoluble or insoluble substance dissolves and recrystallization.With respect to other preparation method, the nanocrystal of Hydrothermal Preparation have grow complete, granularity is little and be evenly distributed, particle agglomeration is light, can use more cheap raw material, advantages such as stoichiometry thing that is easy to get suitable and crystalline form.And crystal grain thing phase, dimension and pattern can be controlled by the control hydrothermal reaction condition; Especially hydrothermal method can prepare the nanocrystalline of complete crystallization and not need high-temperature calcination to handle, and powder hard aggregation, the defective having avoided causing in the calcination process form and the impurity introducing, and therefore, prepared powder has greater activity.
The synthetic report of the hydro-thermal of relevant plumbous tungstate material is more rare, and the prepared tungstate material that goes out is mostly with sphere, and long clavate is main, and its diameter does not wait from the nanometer to the micron order.The performance of Nano material of lead tungstate and the appearance structure of its particle are closely related, so the pattern research of Nano material of lead tungstate is become the key point for preparing the high-performance luminescent material.
Summary of the invention
The objective of the invention is to propose a kind of preparation method of Nano material of lead tungstate.
The preparation method of a kind of Nano material of lead tungstate that the present invention proposes, concrete steps are as follows:
Sodium wolframate and lead salt are placed container respectively, are solvent with the deionized water, add additive, normal temperature stirred 40-60 minute down, moved in the reactor, added the 60%-70% of deionized water to reactor volume in reactor, sealing, reaction is 3-12 hour under 120-160 ℃ of temperature.Reactor is naturally cooled to room temperature, the gained throw out is taken out, washing, centrifugation is also dry, and final product is scattered in the dehydrated alcohol, and this final product is required product; Wherein, the mol ratio of sodium wolframate and lead salt is (0.8-1.2): 1.
Among the present invention, described lead salt is Pb (NO
3)
2, PbAc
2Or PbCl
2Deng in any.
Among the present invention, described additive be among CTAB (cetyl trimethylammonium bromide) or the SDS (sodium lauryl sulphate) etc. any, the additive add-on be the sodium wolframate molar weight 1-2 doubly.
Among the present invention, washing adopts deionized water and dehydrated alcohol to clean 3-8 time respectively.
Among the present invention, utilize the inventive method products therefrom can pass through scanning electronic microscope (SEM), X-ray powder diffraction (XRD) and fluorescence property characterize.
Among the present invention, XRD result shows product pure (consistent with the JCPDS card).Scanning electronic microscope (SEM) shows uniform particle diameter, good dispersity.Show that in the fluorescent spectroscopy result product has photoluminescence performance.
The present invention has following advantage:
1, the present invention under hydrothermal condition, utilize first conditions such as additive, temperature, pH value, reaction times change system studied the pattern and the fluorescence property thereof of prepared tungstate crystal.The appearance of nano material rule for preparing among the present invention, uniform particle diameter, degree of crystallinity is high and have a good fluorescence property.
2. technology of the present invention is simple, and reactant is basic inorganics, and raw material obtains very convenient, cheap, and the processing of product is more convenient, can carry out commercial scale production by amplification.
3, the present invention has certain toxicity except that lead salt in the process of preparation, the equal nontoxicity of other selected reagent, and tensio-active agent major part in place, back phase reason process can obtain reclaiming, and reaches the effect of economical environment-protective.
4, compare the method for solid state reaction, the hydrothermal method mild condition, easily by the temperature, pressure in the control still to reach the effect of control product pattern, structure and performance, better repeatability is arranged.
Description of drawings
Fig. 1 is scanning electronic microscope (SEM) figure in the embodiment of the invention.Wherein, a is a product shape appearance figure (5000X) among the embodiment 1, and b is a product shape appearance figure (2500X) among the embodiment 2, and c is a product shape appearance figure (20000X) among the embodiment 3.
Fig. 2 is the structure iron that the X-ray powder diffraction (XRD) of product in the embodiment of the invention obtains.Wherein, a is the XRD figure of product among the embodiment 1, and b is the XRD figure of product among the embodiment 2, and c is the XRD figure of product among the embodiment 3.
Fig. 3 is the fluorescence emission spectrogram of product in the embodiment of the invention.Wherein, a is the fluorescence spectrum figure of product among the embodiment 1, and b is the fluorescence spectrum figure of product among the embodiment 2, and c is the fluorescence spectrum figure of product among the embodiment 3.
Embodiment
Further specify the present invention below by embodiment.
Embodiment 1
(1) prepares the Pb (NO of 1mol/L respectively
3)
2Aqueous solution 100ml and 1mol/L NaWO
4Aqueous solution 100ml (reagent of employing all is to analyze alcohol).Respectively get in the 1ml adding 100ml beaker and mix, add 0.001molCTAB (cetyl trimethylammonium bromide) then, add a certain amount of deionized water and stir about 1 hour at normal temperatures again, move into then in 50 milliliters of tetrafluoroethylene reactors, in reactor, add the 60%-65% of deionized water to reactor volume, sealing was reacted 3 hours down in 120 ℃.Reactor is naturally cooled to room temperature.
(2) product is taken out, use deionized water and absolute ethanol washing 7-8 time, centrifugation is also dry, final product is dispersed in promptly gets required product in the dehydrated alcohol.
Use scanning electronic microscope (SEM) and x-ray powder diffraction instrument (XRD) that the pattern and the structure of product are characterized respectively, visible TEM shows that product is the PbWO of diameter 400 nanometers, the about 3-4 micron of length from Fig. 1 (a)
4The accurate nanometer rod of spirrillum, visible XRD result shows product pure (consistent with the JCPDS card) from Fig. 2 (a).As seen, fluorescent spectroscopy is the result show from Fig. 3 (a), and product has photoluminescence performance.
Embodiment 2
Prepare the PbAc of 1mol/L respectively
2Aqueous solution 100ml and 1mol/LNaWO
4Aqueous solution 100ml (reagent of employing all is to analyze alcohol).Respectively get in the 1ml adding 100ml beaker and mix, add 0.002molSDS (cetyl trimethylammonium bromide) then, add a certain amount of deionized water and stir about 1 hour at normal temperatures again, move into then in 50 milliliters of tetrafluoroethylene reactors, add the 65%-70% of deionized water in the reactor to reactor volume, sealing was reacted 6 hours down in 140 ℃.Reactor is naturally cooled to room temperature.Product is taken out, use deionized water and absolute ethanol washing 3-6 time, centrifugation is also dry, final product is dispersed in promptly gets required product in the dehydrated alcohol.The product that obtains is pagoda shape PbWO
4Accurate nano material, the crystallographic system of product is identical with embodiment 1.The product purity height, degree of crystallinity is good, and optical property is similar substantially to embodiment 1.Visible TEM shows that product is diameter 300 nanometers, the about 3.5 microns PbWO of length from Fig. 1 (b)
4The accurate nanometer rod of spirrillum, visible XRD result shows product pure (consistent with the JCPDS card) from Fig. 2 (b).As seen, fluorescent spectroscopy is the result show from Fig. 3 (b), and product has photoluminescence performance.
Embodiment 3
Prepare the PbCl of 1mol/L respectively
2Aqueous solution 100m and 1mol/L NaWO
4Aqueous solution 100ml (reagent of employing all is to analyze alcohol).Get 0.8mlPbCl respectively
2The aqueous solution and 1ml NaWO
4The aqueous solution adds in the 100ml beaker, add 0.0015molCTAB (cetyl trimethylammonium bromide) then, add a certain amount of deionized water and stir about 1 hour at normal temperatures again, move into then in 50 milliliters of tetrafluoroethylene reactors, add the 60%-63% of deionized water in the reactor to reactor volume, sealing was reacted 12 hours down in 160 ℃.Reactor is naturally cooled to room temperature.Product is taken out, and with deionized water and absolute ethanol washing, centrifugation is also dry, final product is dispersed in promptly gets required product in the dehydrated alcohol., the PbWO of the about 150nm of product diameter that obtains
4Nanoparticle, the crystallographic system of product is identical with embodiment 1.The product purity height, degree of crystallinity and optical property are good.Optical property is similar substantially to embodiment 1.Visible TEM shows that product is the nanoparticle about diameter 150 nanometers from Fig. 1 (c), and visible XRD result shows product pure (consistent with the JCPDS card) from Fig. 2 (c).As seen, fluorescent spectroscopy is the result show from Fig. 3 (c), and product has photoluminescence performance.
Embodiment 4
Prepare the PbCl of 1mol/L respectively
2Aqueous solution 100ml and 1mol/LNaWO
4Aqueous solution 100ml (reagent of employing all is to analyze alcohol).Get 1.2mlPbCl respectively
2The aqueous solution and 1ml NaWO
4The aqueous solution adds in the 100ml beaker, add 0.002molCTAB (cetyl trimethylammonium bromide) then, add a certain amount of deionized water and stir about 50 minutes at normal temperatures again, move into then in 50 milliliters of tetrafluoroethylene reactors, in reactor, add the 60%-70% of deionized water to reactor volume, sealing was reacted 12 hours down in 160 ℃.Reactor is naturally cooled to room temperature.Product is taken out, and with deionized water and absolute ethanol washing, centrifugation is also dry, final product is dispersed in promptly gets required product in the dehydrated alcohol.
Product structure is similar substantially to embodiment 3 to performance.