CN104069847A

CN104069847A - Preparation method of rear earth europium doped hollow nano TiO2 glass micro beads

Info

Publication number: CN104069847A
Application number: CN201410143092.9A
Authority: CN
Inventors: 张辉; 杨振威
Original assignee: Xian Polytechnic University
Current assignee: Xian Polytechnic University
Priority date: 2014-04-10
Filing date: 2014-04-10
Publication date: 2014-10-01
Anticipated expiration: 2034-04-10
Also published as: CN104069847B

Abstract

The invention discloses a preparation method of rear earth europium doped hollow nano TiO2 glass micro beads. The preparation method of the rear earth europium doped hollow nano TiO2 glass micro beads comprises the following steps: firstly, coating surfaces of hollow glass micro beads with magnetic nano Fe3O4 by ferric sulfate, sodium thiosulfate, urea, polyethylene glycol-1000; then coating a SiO2 intermediate layer with tetraethoxysilane, and finally coating a europium doped nano TiO2 photocatalyst by titanous sulfate, the urea, polyvinylpyrrolidone and europium nitrate, so as to obtain the rear earth element doped hollow magnetic photocatalysis glass micro beads with core-shell structures. By adopting the preparation method, the rear earth europium doped hollow nano TiO2 glass micro beads has the excellent magnetic performance on the premise of not reducing the photocatalysis activity of TiO2.

Description

Rare-earth europium dopen Nano TiO 2the preparation method of hollow glass micropearl

Technical field

The invention belongs to function Inorganic Non-metallic Materials preparation method technical field, relate to the method for the coated modification of a kind of hollow glass micropearl, be specifically related to a kind of rare-earth europium dopen Nano TiO ₂the preparation method of hollow glass micropearl.

Background technology

There are two key issues in the development of solid, liquid photocatalysis system and application: the one, how to improve the catalytic activity of catalyst; The 2nd, the separation of catalyst, reclaim and reuse.As widely used TiO ₂catalysis material, people have carried out in depth research from many aspects such as titanium source category, preparation condition, crystal type, interplanar distance, grain size, rear-earth-doped and dye sensitizations.Research shows, rare earth doped TiO ₂its photo absorption performance, electric charge diffusion, surface reaction, particle diameter and crystal formation etc. are exerted an influence.This be because: 1. formed trap center, rare earth element be valence state lower than the metal ion of+4 valencys, can effectively catch hole, suppress the compound of electronics and hole; 2. form doped energy-band, make electronics and the hole of catching on photon excitation doped energy-band that energy is less, improve the utilization rate of photon; 3. cause the diffusion length of carrier to increase, thereby extend the life-span in electronics and hole, suppress compound; 4. cause lattice defect, be conducive to form more Ti ⁴⁺oxidation center.The rare earth element of doping is mainly the LREE of group of the lanthanides, at TiO ₂the rare earth element of middle doping variety classes and variable concentrations, the variation causing is different.

Nanometer Fe ₃o ₄magnetic-particle, as important functional material, demonstrates excellent performance at aspects such as magnetic fluid material, microwave absorbing material, special catalyst raw materials, becomes one of hot fields of materialogy.At present, nanometer Fe ₃o ₄preparation method mainly contain hydrothermal synthesis method, neutralization precipitation method, microemulsion method, coprecipitation and oxidation-precipitation method etc., wherein hydro-thermal method is prepared nanometer Fe ₃o ₄particle has significant advantage, and the one, relatively high temperature is conducive to the raising of product magnetic property and crystallization degree; The 2nd, in closed container, produce relatively high pressure and avoided component volatilization, improved product purity, reduced pollution.Utilize the key of hydro-thermal method synthesizing nano-scale oxide to be, under HTHP, the solubility of the corresponding hydroxide of oxide in water must be greater than the originally solubility in water of oxide, so hydroxide while precipitated oxide soluble in water, the process of a dissolving, crystallization has only been experienced in the formation of oxide like this, prepared nanocrystalline growth is comparatively complete, crystallite dimension is little, narrow particle size distribution, reunion degree is low, and do not need high-temperature calcination pretreatment, avoided the introducing of grain growth, defect formation and impurity.In addition, due to the formed hyperbaric environment of system itself, it is very even that reaction is carried out.Under hydrothermal condition, by controlling the conditions such as reaction temperature, reaction time and raw material proportioning, can access the product of different crystal structure, composition, pattern and particle size, uniform particles, favorable dispersibility, need not high-temperature roasting, and process is polluted little, simple to operate, easily realize the advantages such as suitability for industrialized production.

Hollow glass micropearl is the small hollow glass spheres of a kind of size, having the advantages such as light weight, low heat conduction, resistance to compression, high dispersive, sound insulation, electrical insulating property and Heat stability is good, is the novel light material of a kind of of many uses, the excellent performance that gets up of development in recent years.Utilize the feature of hollow glass micropearl light weight, hollow, it is carried out to surface modification treatment, can access the new material with specific function.

Use at present ferric sulfate, sodium thiosulfate and urea to adopt hydro-thermal method to hollow glass micropearl coated magnetic nanometer Fe ₃o ₄particle, is then used ethyl orthosilicate to be coated flower ball-shaped SiO ₂intermediate layer, is finally used titanium sulfate, urea and europium nitrate to be coated europium dopen Nano TiO ₂the composite modifying method of photocatalysis layer does not also have.

Summary of the invention

The object of this invention is to provide a kind of rare-earth europium dopen Nano TiO ₂the preparation method of hollow glass micropearl, has realized and has not reduced TiO ₂under the prerequisite of photocatalytic activity, given the magnetic property of hollow glass micropearl excellence.

The technical solution adopted in the present invention is, rare-earth europium dopen Nano TiO ₂the preparation method of hollow glass micropearl, specifically implements according to following steps:

Step 1, to hollow glass micropearl clean, flotation and pretreatment;

Step 2, preparation coupling modification mixed solution, utilize coupling modification mixed solution to carry out rich surface amination processing to the hollow glass micropearl obtaining through step 1;

Step 3, the amidized hollow glass micropearl of the rich surface obtaining through step 2 is carried out to clad nano Fe ₃o ₄modification;

Step 4, to the clad nano Fe obtaining through step 3 ₃o ₄hollow glass micropearl carries out coated Si O ₂process;

Step 5, by the coated flower ball-shaped SiO obtaining through step 4 ₂magnetic hollow glass microballoon be coated rare-earth europium dopen Nano TiO ₂process, obtain rare-earth europium dopen Nano TiO ₂magnetic photocatalytic hollow glass micropearl.

Feature of the present invention is also:

Step 1 is specifically implemented according to following steps:

Step 1.1, get respectively hollow glass micropearl and running water, first the temperature of running water is warming up to 35 ℃～45 ℃, then hollow glass micropearl is added in running water, by adding the hollow glass micropearl of 10g～20g in every liter of running water, speed with 100rpm～200rpm stirs the hollow glass micropearl 5min～10min in running water, the temperature of running water is risen to 70 ℃～90 ℃ again, constant temperature soaks hollow glass micropearl 50min～70min, standing until naturally cool to room temperature, after hollow glass micropearl layering, the hollow glass micropearl swimming on running water liquid level is fished for out, separately get clean running water and rinse the hollow glass micropearl fishing for out 1 time～3 times, drain deionized water, complete the flotation of hollow glass micropearl and cleaning, obtain clean hollow glass micropearl,

Step 1.2, for 1:0.8～1.2, take respectively clean hollow glass micropearl, the NaOH obtaining through step 1.1 in mass ratio, the NaOH taking is added in deionized water, be mixed with 10g/L～20g/L sodium hydroxide solution;

Step 1.3, the sodium hydroxide solution first step 1.2 being made are warming up to 40 ℃～80 ℃, again the clean hollow glass micropearl taking through step 1.2 is poured in sodium hydroxide solution and soaked, speed with 100rpm～200rpm stirs 10min～30min, then the hollow glass micropearl soaking in sodium hydroxide solution is fished for out, by deionized water, wash, until the pH value of the deionized water after washing is neutrality, complete the pretreatment to hollow glass micropearl;

Step 1.4, will be through the pretreated hollow glass micropearl of step 1.3 drying 2h～4h under 110 ℃～150 ℃ conditions.

Step 2 is specifically implemented according to following steps:

Step 2.1, for 1:8～10, measure respectively absolute ethyl alcohol and deionized water by volume, absolute ethyl alcohol and deionized water are hybridly prepared into ethanolic solution;

Step 2.2, take the hollow glass micropearl obtaining through step 1, measure the ethanolic solution through step 2.1 preparation, by the hollow glass micropearl of every gram, get the ethanolic solution of 0.025L～0.05L;

Take silane resin acceptor kh-550, the quality of silane resin acceptor kh-550 is 10%～30% of the hollow glass micropearl quality that takes;

Step 2.3, the silane resin acceptor kh-550 taking in step 2.2 is dropwise added in the ethanolic solution that step 2.2 measures, first with the speed of 100rmp～200rpm, stir the ethanolic solution of silane resin acceptor kh-550, form mixed solution, then with glacial acetic acid, regulating the pH value of mixed solution is 3.5～5.5, obtains coupling modification mixed solution;

Step 2.4, the hollow glass micropearl taking through step 2.2 is added in the coupling modification mixed solution obtaining through step 2.3, speed with 100rpm～200rpm stirs the hollow glass micropearl in coupling modification mixed solution, standing 8h～the 12h of constant temperature after again coupling modification mixed solution being warming up to 20 ℃～40 ℃, then carry out vacuum filtration processing, hollow glass micropearl after coupling modification is separated from coupling modification mixed solution, obtain the hollow glass micropearl after coupling modification, then the hollow glass micropearl after coupling modification is cleaned 1 time～3 times with absolute ethyl alcohol,

Step 2.5, by dispersed the coming of hollow glass micropearl after step 2.4 is processed, be placed under the ultraviolet lamp that dominant wavelength is 365nm and irradiate 30min～60min, then the hollow glass micropearl irradiating through ultraviolet lamp is positioned under the temperature conditions of 70 ℃～90 ℃ and carries out preliminary drying, the preliminary drying time is 2h～4h, be positioned over again under the temperature conditions of 110 ℃～130 ℃ and bake 1min～3min, obtain the amidized hollow glass micropearl of rich surface.

Step 3 is specifically implemented according to following steps:

Step 3.1, for 1:0.25～1.5:3～30:0.5～6, get respectively ferric sulfate, sodium thiosulfate, urea and PEG-6000 in molar ratio;

First ferric sulfate is added in the deionized water of 30 ℃～60 ℃ of temperature, be mixed with the ferrum sulfuricum oxydatum solutum that molar concentration is 0.03mol/L～0.1mol/L, again by the ferrum sulfuricum oxydatum solutum preparing through sonic oscillation 5min～10min, until ferric sulfate, being dissolved in deionized water is completely after yellow transparent solution, add sodium thiosulfate and fully stir, solution colour becomes pitch black purple, continue to stir and become achromaticity and clarification, now add urea, PEG-6000, continue to stir until solution is white in color colloidal suspension, prepare modified solution;

Step 3.2, take the amidized hollow glass micropearl of the rich surface obtaining through step 2, measure the modified solution through step 3.1 preparation, by every gram of amidized hollow glass micropearl of rich surface, get the modified solution of 0.05L～0.1L; The amidized hollow glass micropearl of rich surface is added in modified solution, the more amidized hollow glass micropearl of rich surface is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution;

After step 3.3, sealing stainless steel cauldron, stainless steel cauldron is placed in to homogeneous reactor, with 1 ℃/min～2 ℃/min speed, be warming up to 120 ℃～180 ℃, isothermal reaction 3h～8h, after stainless steel cauldron is naturally cooling, take out the hollow glass micropearl that is black, utilize the floatability of hollow glass micropearl that hollow glass micropearl is separated with remaining waste liquid after reaction, obtain the hollow glass micropearl after modification;

Step 3.4, the hollow glass micropearl after the modification obtaining through step 3.3 is first used to deionized water rinsing 1 time～3 times, then use absolute ethanol washing 1 time～3 times, finally, in 60 ℃～80 ℃ vacuum drying 12～24h, obtain clad nano Fe ₃o ₄hollow glass micropearl.

Step 4 is specifically implemented according to following steps:

Step 4.1, according to volume ratio, be that 1:4～6 measure respectively deionized water and absolute ethyl alcohol, the deionized water measuring is mixed with absolute ethyl alcohol, make ethanolic solution, re-using mass percent concentration and be 24%～26% ammoniacal liquor, to regulate the pH value of ethanolic solution be 7.8～8.2, formation mixed solution;

Step 4.2, for 1:1.7～1.8, measure respectively absolute ethyl alcohol and ethyl orthosilicate by volume, the absolute ethyl alcohol measuring is mixed with ethyl orthosilicate, make ethyl orthosilicate alcohol mixed solution;

Step 4.3, take the clad nano Fe obtaining through step 3 ₃o ₄hollow glass micropearl, measure in step 4.1 mixed solution of preparation, by every gram of clad nano Fe ₃o ₄hollow glass micropearl get 0.025L～0.05L mixed solution, by the clad nano Fe taking ₃o ₄hollow glass micropearl adds in the mixed solution measuring, and under 40 ℃～60 ℃ conditions, the speed stirring 5min～10min with 200r/min～500r/min, then dropwise adds the ethyl orthosilicate alcohol mixed solution in step 4.2, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got 0.02L～0.04L ethyl orthosilicate alcohol mixed solution, continue to stir 6h～12h, after reaction finishes by hollow glass micropearl with react afterwards remaining fluid separation applications, the hollow glass micropearl of separating is first used to washed with de-ionized water 1 time～3 times, then use absolute ethanol washing 1 time～3 times, again in 75 ℃～85 ℃ vacuum drying 1h～3h, finally bake 5min～10min in 140 ℃～160 ℃, obtain coated flower ball-shaped SiO ₂magnetic hollow glass microballoon.

Step 5.1, for 1:0.2～20:0.0004～0.006:0.0005～0.01, get respectively titanium sulfate, urea, polyvinylpyrrolidone and europium nitrate in molar ratio, titanium sulfate is dissolved in the deionized water of 55 ℃～65 ℃, through sonic oscillation 5min～10min, then add successively urea, polyvinylpyrrolidone and europium nitrate, fully stir it is fully dissolved, obtain modified solution A;

Step 5.2, will obtain coated flower ball-shaped SiO through step 4 ₂magnetic hollow glass microballoon add in the modified solution A obtaining through step 5.1, by every gram of coated flower ball-shaped SiO ₂magnetic hollow glass microballoon add the modified solution A of 0.025L～0.05L, will be coated flower ball-shaped SiO ₂magnetic hollow glass microballoon together with modified solution A, be transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene, sealing stainless steel cauldron;

Step 5.3, by sealing after stainless steel cauldron be placed in homogeneous reactor, with 1 ℃/min～2 ℃/min speed, be warming up to 110 ℃～160 ℃, isothermal reaction 2h～5h, after stainless steel cauldron is naturally cooling, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, the hollow glass micropearl of separating is first used to deionized water rinsing 1 time～3 times, absolute ethanol washing is 1～3 time again, finally dry, obtain rare-earth europium dopen Nano TiO ₂magnetic photocatalytic hollow glass micropearl.

In step 5.3 by the hollow glass micropearl of separating vacuum drying under 60 ℃～80 ℃ conditions.

The invention has the beneficial effects as follows:

(1) rare-earth europium dopen Nano TiO of the present invention ₂the preparation method of hollow glass micropearl adopts hydro-thermal method preparing magnetic Nano Fe ₃o ₄in the time of particle, direct hollow glass micropearl surface coated magnetic nanometer Fe after coupling modification ₃o ₄film, gives hollow glass micropearl magnetic property; By controlling reaction temperature and time, the technological parameters such as consumption of predecessor, precipitating reagent and surfactant, optimize modified technique, and the method is saved raw material, easy and simple to handle.

(2) rare-earth europium dopen Nano TiO of the present invention ₂in the preparation method of hollow glass micropearl, take ethyl orthosilicate as raw material, ammoniacal liquor are hydrolytic accelerating agent, adopt the precipitation method at the coated flower ball-shaped SiO in magnetic hollow glass microballoon surface ₂intermediate layer, not only can be by Fe ₃o ₄with outer TiO ₂keep apart, prevent that light induced electron is by Fe ₃o ₄catch reduction photocatalytic activity, and flower ball-shaped SiO ₂surface has increased the specific area of hollow glass micropearl, is photochemical catalyst TiO ₂larger space is provided.

(3) rare-earth europium dopen Nano TiO of the present invention ₂in the preparation method of hollow glass micropearl, take titanium sulfate and urea as predecessor, and polyvinylpyrrolidone is surfactant, and europium nitrate is rear-earth-doped element, by controlling reaction condition and material proportion, and coated europium dopen Nano TiO ₂, improve nano-TiO ₂photocatalytic activity under ultraviolet ray and radiation of visible light.

(4) adopt rare-earth europium dopen Nano TiO of the present invention ₂the hollow glass micropearl that the preparation method of hollow glass micropearl obtains, result shows after tested, nanometer Fe ₃o ₄coated hollow glass bead is even, binding strength good, has superparamagnetism, and saturation magnetization reaches 13.12emug ^-1; The rare earth doped TiO that makes ₂absorb light generation red shift, under ultraviolet ray and visible ray irradiation, photocatalytic activity improves, and saturation magnetization is at 8.73emug ^-1, under low-intensity magnetic field condition, be convenient to reclaim, recycle stability high, reuse 10 photocatalytic activities and reduce less than 10%.

Accompanying drawing explanation

Fig. 1 is the stereoscan photograph of the common hollow glass micropearl processed without preparation method of the present invention;

Fig. 2 adopts preparation method of the present invention to hollow glass micropearl coated magnetic nanometer Fe ₃o ₄after stereoscan photograph;

Fig. 3 adopts preparation method of the present invention to the coated flower ball-shaped SiO of hollow glass micropearl ₂the stereoscan photograph in intermediate layer;

Fig. 4 adopts preparation method of the present invention to the coated rare-earth europium dopen Nano TiO of hollow glass micropearl ₂after stereoscan photograph;

Fig. 5 is the B-H loop that adopts the hollow glass micropearl that preparation method of the present invention prepared in different phase;

Fig. 6 adopts rare-earth europium doped magnetic photocatalysis hollow glass micropearl that preparation method of the present invention prepares and the X-ray diffraction spectrogram of doped magnetic photocatalysis hollow glass micropearl not;

Fig. 7 adopts rare-earth europium doping prepared by the inventive method and the ln (C of doped magnetic photocatalysis hollow glass micropearl ultraviolet irradiation photocatalytic degradation methylene blue solution not ₀/ C _t)-t curve.

The specific embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Rare-earth europium dopen Nano TiO of the present invention ₂the preparation method of hollow glass micropearl, first uses ferric sulfate, sodium thiosulfate, urea, PEG-6000 in hollow glass micropearl surface coated magnetic nanometer Fe ₃o ₄, then use ethyl orthosilicate coated Si O ₂intermediate layer, is finally used titanium sulfate, urea, polyvinylpyrrolidone and europium nitrate to be coated europium dopen Nano TiO ₂photochemical catalyst, prepares a kind of rare earth doped magnetic photocatalytic hollow glass micropearl of nucleocapsid structure that has; Specifically according to following steps, implement:

Step 1, to hollow glass micropearl clean, flotation and pretreatment:

Although the compression strength of hollow glass micropearl is higher, but in producing, store and dividing process of assembling, likely there is breakage or introduce impurity, therefore be necessary to hollow glass micropearl clean, flotation also will carry out pretreatment to clean hollow glass micropearl, to facilitate modification below;

Step 2, preparation coupling modification mixed solution, utilize coupling modification mixed solution to carry out rich surface amination processing to the hollow glass micropearl obtaining through step 1:

Step 3, the amidized hollow glass micropearl of the rich surface obtaining through step 2 is carried out to clad nano Fe ₃o ₄modification:

Step 4, to the clad nano Fe obtaining through step 3 ₃o ₄hollow glass micropearl carries out coated Si O ₂process:

Step 4.3, take the clad nano Fe obtaining through step 3 ₃o ₄hollow glass micropearl, measure in step 4.1 mixed solution of preparation, by every gram of clad nano Fe ₃o ₄hollow glass micropearl get 0.025L～0.05L mixed solution, by the clad nano Fe taking ₃o ₄hollow glass micropearl adds in the mixed solution measuring, and under 40 ℃～60 ℃ conditions, the speed stirring 5min～10min with 200r/min～500r/min, then dropwise adds the ethyl orthosilicate alcohol mixed solution in step 4.2, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got 0.02L～0.04L ethyl orthosilicate alcohol mixed solution, continue to stir 6h～12h, reaction finish the rear floatability of utilizing hollow glass micropearl by its with react remaining fluid separation applications afterwards, the hollow glass micropearl of separating is first used to washed with de-ionized water 1 time～3 times, then use absolute ethanol washing 1 time～3 times, again in 75 ℃～85 ℃ vacuum drying 1h～3h, finally bake 5min～10min in 140 ℃～160 ℃, obtain coated flower ball-shaped SiO ₂magnetic hollow glass microballoon.

Step 5, by the coated flower ball-shaped SiO obtaining through step 4 ₂magnetic hollow glass microballoon be coated rare-earth europium dopen Nano TiO ₂process rare-earth europium dopen Nano TiO ₂magnetic photocatalytic hollow glass micropearl:

Step 5.3, by sealing after stainless steel cauldron be placed in homogeneous reactor, with 1 ℃/min～2 ℃/min speed, be warming up to 110 ℃～160 ℃, isothermal reaction 2h～5h, after stainless steel cauldron is naturally cooling, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, the hollow glass micropearl of separating is first used to deionized water rinsing 1 time～3 times, absolute ethanol washing is 1～3 time again, finally, in 60 ℃～80 ℃ vacuum dryings, obtain rare-earth europium dopen Nano TiO ₂hollow glass micropearl, this rare-earth europium dopen Nano TiO ₂hollow glass micropearl is the magnetic photocatalytic hollow glass micropearl that europium doping has nucleocapsid structure.

Fig. 1 is the stereoscan photograph of coated hollow glass bead not, and as seen from Figure 1, the surface of unmodified hollow glass micropearl is very clean, does not have other materials to adhere to; Fig. 2 is hollow glass micropearl clad nano Fe ₃o ₄after stereoscan photograph, as seen from Figure 2, hollow glass micropearl has been coated the granular material of one deck, through high power electromicroscopic photograph, show, this clad is that the spheric granules that is 40nm left and right by average grain diameter forms, and particle size distribution is even, and bead surface is coated complete; Fig. 3 is the coated flower ball-shaped SiO of hollow glass micropearl ₂the stereoscan photograph in intermediate layer, as seen from Figure 3, coated Si O ₂after hollow glass micropearl surface become very coarse, be flower ball-shaped, through high power electromicroscopic photograph, show, these flower ball-shaped projections are comprised of particle diameter 200nm particle, outward appearance presents " ridge-mountain valley " special appearance; Fig. 4 is the coated rare-earth europium dopen Nano TiO of hollow glass micropearl ₂after stereoscan photograph, as seen from Figure 4, coated europium doped Ti O ₂after " ridge-mountain valley " pattern become fuzzyyer, relatively smooth, surperficial most of groove is filled up by some tiny particles, through high power electromicroscopic photograph, shows, surface consists of the less particle of particle diameter.

Fig. 5 is the B-H loop of the hollow glass micropearl prepared of different phase, as seen from Figure 5, and clad nano Fe ₃o ₄after hollow glass micropearl magnetic the strongest, saturation magnetization is 13.12emu/g; Coated Si O ₂after the saturation magnetization of hollow glass micropearl drop to some extent 7.37emu/g, this is because coated Si O ₂rear hollow glass micropearl quality obviously increases, magnetic Nano Fe ₃o ₄due to proportion reduces; Be coated again europium dopen Nano TiO ₂after the saturation magnetization of hollow glass micropearl be increased to 8.73emug ^-1, this is that hysteresis is obvious because rare-earth europium element has certain magnetic.

Fig. 6 is the X-ray diffraction spectrogram of the hollow glass micropearl prepared of different phase.Test result shows, clad nano Fe ₃o ₄rear hollow glass micropearl at 30.2 °, 2 θ angle, 35.6 °, 43.3 °, 57.2 ° and 63.0 ° locate to have occurred obvious diffraction maximum, respectively corresponding (220), (311), (400), (511) and (404) crystal face, consistent with standard diagram JCPDS No.03-0863, be inverse spinel magnetic iron ore structure; Coated Si O ₂after hollow glass micropearl diffraction maximum there is no significant change; Be coated again europium dopen Nano TiO ₂hollow glass micropearl at 25.3 °, 2 θ angle, 37.0 °, 48.2 °, 52.8 ° and 54.9 ° locate to have occurred anatase TiO ₂diffraction maximum, respectively corresponding (101), (004), (200), (105) and (211) crystal face, consistent with standard diagram JCPDS No.21-1167.

Fig. 7 is not doping and the rare-earth europium dopen Nano TiO that adopts the inventive method to prepare ₂ln (the C of magnetic photocatalytic hollow glass micropearl photocatalytic degradation methylene blue under ultraviolet ray is irradiated ₀/ C _t)-t curve.As seen from Figure 7, the europium doped Ti O that the inventive method obtains ₂the photocatalysis effect of nucleocapsid structure hollow glass micropearl is obviously better than not doped Ti O ₂nucleocapsid structure hollow glass micropearl.

Being determined as follows of photocatalytic degradation methylene blue dye activity:

Take 0.03g hollow glass micropearl, added to 50mL, mass concentration is in the methylene blue solution of 5mg/L, being placed in darkroom 90min reaches after adsorption equilibrium, the glass culture dish (diameter 8cm) that methylene blue solution is housed is placed on to quartz ultraviolet lamp (power 40W, dominant wavelength 254nm) under, carry out irradiation, light source distance liquid level 10cm, every 1h, with UV-1600 type ultraviolet-uisible spectrophotometer, measure solution in the absorbance A at 664nm place, according to methylene blue solution absorbance and concentration standard curve (regression equation: A=0.0012+0.0958C, coefficient R=0.9996), calculate the concentration of methylene blue solution, draw ln (c ₀/ c _t)-t curve, and according to the degradation rate D of formula (1) calculating methylene blue dye.

D = \frac{C_{0} - C_{t}}{C_{0}} \times 100 % - - - (1);

C wherein ₀the initial concentration of the saturated rear methylene blue solution of absorption, C _tbe the concentration of methylene blue solution after irradiation certain hour, t is the ultraviolet irradiation time.

With VSM multifunction vibration sample magnetometer (U.S. Quantum Design company), measure the hysteresis curve of coated hollow glass bead, calculate saturation magnetization.

Beneficial effect of the present invention place is described from principle aspect:

1. the present invention is by controlling coupling agent consumption, and reaction temperature and time, regulator solution pH value, makes hollow glass micropearl surface grafting amino as much as possible, is beneficial to clad nano Fe ₃o ₄particle, improves binding strength; After silane resin acceptor kh-550 consumption is pretreatment, 10%～30% of hollow glass micropearl quality time, coupling modified effect is better; After silane resin acceptor kh-550 consumption is lower than pretreatment, during hollow glass micropearl quality 10%, seldom, coupling modified effect is poor for hollow glass micropearl surface grafting amount; After silane resin acceptor kh-550 consumption is higher than pretreatment 30% of hollow glass micropearl quality time, poly-reaction in occurring between the large molecule of coupling agent, coupling modified effect is poor, causes waste.

Coupling reaction temperature affects the hydrolysis rate of silane resin acceptor kh-550, and temperature is higher, and coupling agent hydrolysis rate is just faster.When temperature is controlled at 20～40 ℃, can obtain good modified effect; When temperature during lower than 20 ℃ hydrolysis rate slower, the reaction time is long, production efficiency is low; When temperature is during higher than 40 ℃, hydrolysis rate is too fast, and the silane coupler after hydrolysis is not able to do in time, with bead surface hydroxy combining, self condensation just occurs, and causes coupling agent waste.

Along with the prolongation of coupling reaction time, coupling agent increases gradually at bead surface covering amount; When the reaction time is less than 8h, coupling agent can not be fully used; When the reaction time is greater than 12h, coupling agent fundamental reaction is complete, then time expand does not improve modified effect.

The pH value of coupling modification mixed solution affects the association rate of Si-OH and the silane resin acceptor kh-550 on hollow glass micropearl surface: when the pH value of coupling modification mixed solution is 3.5～5.5 time, silane resin acceptor kh-550 is combined well with hollow glass micropearl surface Si-OH, can make full use of silane resin acceptor kh-550, Reaction time shorten; When the pH value of coupling modification mixed solution is less than 3.5 or while being greater than 5.5, coupling modified effect all declines.

2. the consumption of ferric sulfate, sodium thiosulfate and urea, ratio, the loading ratio of hollow glass micropearl, dosage of surfactant, the factors such as reaction temperature and time, all affect nanometer Fe ₃o ₄purity, crystallization degree, pattern and the particle size of clad; When the molar concentration of ferric sulfate is during at 0.015mol/L～0.05mol/L, hollow glass micropearl surface can be coated certain thickness magnetic Nano Fe ₃o ₄film, particle generation agglomeration obviously reduces, and can not deposit too many nano particle in solution simultaneously, is combined firmly with hollow glass micropearl; When the molar concentration of ferric sulfate is less than 0.015mol/L, Fe in solution ³⁺very little, hollow glass micropearl surface is coated imperfect for ion; When the molar concentration of ferric sulfate is greater than 0.05mol/L, Fe ³⁺concentration is excessive, the too thick hollow glass micropearl precipitation that easily causes of clad, and nano particle also easily comes off.

Urea provides an alkaline reaction environment, when ferric sulfate and urea mol ratio are during in 1:3～30, can generate magnetic Nano Fe ₃o ₄; When ferric sulfate and urea mol ratio are greater than 1:30, product color is slightly partially red; When ferric sulfate and urea mol ratio are less than 1:3, product color is partially blue.

When ferric sulfate and sodium thiosulfate mol ratio are 1:0.25～1.5, can generate magnetic Nano Fe ₃o ₄, hollow glass micropearl surface is coated continuous, complete, and nano particle is combined with hollow glass micropearl firmly; When ferric sulfate and sodium thiosulfate mol ratio are greater than 1:1.5, Fe ³⁺consumption reduces relatively, contains a large amount of sulphur simple substance in product, not only can reduce nanometer Fe ₃o ₄purity, and increased the weight of hollow glass micropearl; When ferric sulfate and sodium thiosulfate mol ratio are less than 1:0.25, the Fe that reduction obtains ²⁺measure very little the Fe of generation ₃o ₄complicated component, may contain part Fe ₂o ₃, crystallization degree is low, and hollow glass micropearl surface is coated imperfect, and color is yellowish-brown or khaki.

Reaction temperature and reaction time major effect Fe ₃o ₄crystallization degree, crystal morphology and size: when reaction temperature is during at 120 ℃～180 ℃, can generate magnetic Nano Fe ₃o ₄; When reaction temperature is during lower than 120 ℃, generate taupe or celadon material, there is no magnetic; When reaction temperature is during higher than 180 ℃, nanometer particle size enlarges markedly, and high temperature also can cause silane resin acceptor kh-550 to decompose, and causes covering amount to reduce, and instrument security reduces; When the reaction time is controlled at 3h～8h, can be in hollow glass micropearl coated with uniform one deck nanometer Fe ₃o ₄film; When the reaction time is less than 3h, nano particle crystallization degree reduces, with hollow glass micropearl binding strength variation; When the reaction time is greater than 8h, nano particle is reunited, and particle diameter obviously increases, and hollow glass micropearl rough surface is uneven, and particle easily comes off.

The kind of surfactant and consumption, not only affect the size of nanocrystal, and the proterties of product and coated state also had a significant impact.Use surfactant polyethylene-1000 can obviously improve the coated pattern of bead surface.When ferric sulfate and PEG-6000 mol ratio are during in 1:0.5～6, hollow glass micropearl surface is coated complete, even; When ferric sulfate and PEG-6000 mol ratio are less than 1:0.5, nanocrystalline grain size increases, and covered effect is bad; When ferric sulfate and PEG-6000 mol ratio are greater than 1:6, the magnetic of product reduces or disappears.

The loading of hollow glass micropearl is than directly affecting utilization ratio and the covered effect of product.When hollow glass micropearl consumption is 10g/L～20g/L, microballon color is black, and sedimentation does not occur, and cladding ratio is more even; When hollow glass micropearl consumption is less than 10g/L, total concentration of iron is excessive, and clad is too thick, and hollow glass micropearl major part is deposited in container bottom and can not be floating; When hollow glass micropearl consumption is greater than 20g/L, clad attenuation, color shoals, coated inhomogeneous.

3. hollow glass micropearl coated Si O ₂in process, reaction temperature, reaction time and loading ratio affect SiO ₂the pattern of clad and bonding state.When reaction temperature is at 40 ℃～60 ℃, during reaction time 6h～12h, hollow glass micropearl surface can form the clad that certain thickness outward appearance is flower ball-shaped, can be by Fe ₃o ₄with TiO ₂keep apart; When reaction temperature is during lower than 40 ℃, reaction can not normally be carried out; When reaction temperature is during higher than 60 ℃, ethanol rate of volatilization is obviously accelerated, and causes solvent waste, and reacting material concentration increases.When the reaction time is less than 6h, the SiO of generation ₂on the low side, coated imperfect, easily come off; When the reaction time surpasses 12h, clad is blocked up.When hollow glass micropearl useful load is during at 20g/L～40g/L, covered effect is better, and outward appearance is flower ball-shaped; When useful load is less than 20g/L, clad is blocked up, and smooth surface loses flower ball-shaped structure, easily precipitates; When useful load is greater than 40g/L, clad is too thin, can not form complete clad.

4. the rare earth doped atom of rare earth element that can make directly enters nano-TiO ₂crystal structure is inner, because doping is very small, to nano-TiO ₂coated hollow glass bead surface topography, color and appearance effects are little, major effect TiO ₂photocatalytic activity.When titanium sulfate and europium nitrate mol ratio are during in 1:0.0005～0.01, europium dopen Nano TiO ₂the photocatalytic activity of coated hollow glass bead significantly improves; When titanium sulfate and europium nitrate mol ratio are less than 1:0.0005 or are greater than 1:0.01, photocatalytic activity changes not obvious or photocatalytic activity and disappears.

Embodiment 1

Take the hollow glass micropearl of 10g, add 1L, temperature to and be in the running water of 40 ℃, with 100rpm speed, stir 5min, then running water is warming up to 70 ℃, constant temperature immersion treatment 1h, make it standing until naturally cool to room temperature, after hollow glass micropearl layering, the hollow glass micropearl that swims in running water liquid level upper strata is pulled out, separately take from water and rinse 1 time, complete the flotation of hollow glass micropearl and cleaning, obtain clean hollow glass micropearl; The NaOH of 10g is added in the deionized water of 1L to the sodium hydroxide solution that preparation mass concentration is 10g/L; Getting the clean hollow glass micropearl floatingly selecting, to add temperature to be that 40 ℃, mass concentration are in 10g/L sodium hydroxide solution, with the hollow glass micropearl 10min in the speed stir process sodium hydroxide solution of 100rpm, then hollow glass micropearl is fished for out, the hollow glass micropearl of fishing for out with clean deionized water washing, until the pH value of the deionized water after washing is neutrality, complete the pretreatment to hollow glass micropearl; By the hollow glass micropearl drying 4h under 110 ℃ of conditions after filtering;

For 1:9, measure respectively absolute ethyl alcohol and deionized water by volume, absolute ethyl alcohol and deionized water are hybridly prepared into the ethanolic solution of 1L, take the pretreated hollow glass micropearl that drying is crossed, according to 10% of this hollow glass micropearl quality, take aminopropyl triethoxysilane KH-550 coupling agent, aminopropyl triethoxysilane KH-550 coupling agent is dropwise added in the ethanolic solution of preparation, first the speed with 100rpm stirs, form mixed solution, then with glacial acetic acid, regulating the pH value of mixed solution is 3.5, obtains coupling modification mixed solution; Pretreated hollow glass micropearl is added in coupling modification mixed solution, speed with 100rpm stirs, immersion treatment 12h under 20 ℃ of conditions, carry out after vacuum filtration, hollow glass micropearl after coupling modification is separated from coupling modification mixed solution, the hollow glass micropearl after coupling modification is cleaned 3 times with absolute ethyl alcohol; Come the hollow glass micropearl after coupling modification is dispersed, be placed under the ultraviolet lamp that dominant wavelength is 365nm and irradiate 60min, then the hollow glass micropearl irradiating through ultraviolet lamp is positioned over to 70 ℃ of preliminary drying 4h, then be positioned over 110 ℃ and bake 3min;

For 1:0.25:3:0.5, get respectively ferric sulfate, sodium thiosulfate, urea and PEG-6000 in molar ratio, in the deionized water that first ferric sulfate to be added to temperature and be 30 ℃, volume be 1L, adopt sonic oscillation 5min, until ferric sulfate, being dissolved in deionized water is completely after yellow transparent solution, add sodium thiosulfate and fully stir, solution colour becomes pitch black purple, continue to stir and become achromaticity and clarification, now add urea, PEG-6000, continue to stir until solution is white in color colloidal suspension, prepare modified solution; The amidized hollow glass micropearl of rich surface of getting 10g adds in modified solution, and the amidized hollow glass micropearl of rich surface is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution; After sealing stainless steel cauldron, stainless steel cauldron is placed in to homogeneous reactor, with 1 ℃/min speed, be warming up to 120 ℃, isothermal reaction 3h, the naturally cooling rear taking-up of question response still is the hollow glass micropearl of black, utilize the floatability of hollow glass micropearl that hollow glass micropearl is separated with remaining waste liquid after reaction, obtain the hollow glass micropearl after modification; Hollow glass micropearl after modification is first used to deionized water rinsing 1 time, then use absolute ethanol washing 1 time, finally, in 60 ℃ of vacuum drying 12h, obtain clad nano Fe ₃o ₄hollow glass micropearl;

According to volume ratio, be that 1:5 measures respectively deionized water and absolute ethyl alcohol, the deionized water measuring is mixed with absolute ethyl alcohol, make ethanolic solution, re-using mass percent concentration and be 25% ammoniacal liquor, to regulate the pH value of ethanolic solution be 8, formation mixed solution; For 1:1.75, measure respectively absolute ethyl alcohol and ethyl orthosilicate by volume, the absolute ethyl alcohol measuring is mixed with ethyl orthosilicate, make ethyl orthosilicate alcohol mixed solution; Take clad nano Fe ₃o ₄hollow glass micropearl, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got the mixed solution of 0.05L, by clad nano Fe ₃o ₄hollow glass micropearl adds in mixed solution, and under 40 ℃ of conditions, the speed stirring 5min with 200r/min, then dropwise adds ethyl orthosilicate alcohol mixed solution, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got 0.02L ethyl orthosilicate alcohol mixed solution, continue to stir 6h, reaction finish the rear floatability of utilizing hollow glass micropearl by its with react remaining fluid separation applications afterwards, by the hollow glass micropearl of separating washed with de-ionized water 1 time, with absolute ethanol washing 1 time, in 80 ℃ of vacuum drying 1h, 150 ℃ bake 5min, obtain coated flower ball-shaped SiO ₂magnetic hollow glass microballoon;

For 1:0.2:0.0004:0.0005, get respectively titanium sulfate, urea, polyvinylpyrrolidone and europium nitrate in molar ratio, it is 60 ℃ that titanium sulfate is dissolved in to temperature, volume is in the deionized water of 1L, sonic oscillation 5min, then add successively urea, polyvinylpyrrolidone and europium nitrate, fully stir it is dissolved completely, make modified solution, then add coated flower ball-shaped SiO ₂magnetic hollow glass microballoon, hollow glass micropearl is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution, after sealed reactor, reactor is placed in to homogeneous reactor, with 1 ℃/min speed, be warming up to 110 ℃, isothermal reaction 2h, the reacted hollow glass micropearl of the naturally cooling rear taking-up of question response still, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, with deionized water rinsing 1 time, absolute ethanol washing 1 time, 60 ℃ of vacuum dryings, obtain rare-earth europium dopen Nano TiO ₂the preparation method of hollow glass micropearl.

Photocatalytic degradation methylene blue dye test result shows, by 0.03g rare-earth europium dopen Nano TiO ₂hollow glass micropearl adds in the methylene blue solution of 50mL, mass concentration 5mg/L, be placed in irradiation under the ultraviolet lamp that is placed on 40W, dominant wavelength 254nm after the 90min of darkroom, light source distance liquid level 10cm, through 8h ultraviolet irradiation, methylene blue dye photocatalytic activity is 87.5%.With VSM multifunction vibration sample magnetic strength instrumentation, determine rare-earth europium dopen Nano TiO ₂the B-H loop of hollow glass micropearl, calculating saturation magnetization is 1.86emu/g.

Embodiment 2

Take the hollow glass micropearl of 20g, add 1L, temperature to and be in the running water of 70 ℃, with 200rpm speed, stir 10min, then running water is warming up to 90 ℃, constant temperature immersion treatment 1h, make it standing until naturally cool to room temperature, after hollow glass micropearl layering, the hollow glass micropearl that swims in running water liquid level upper strata is pulled out, separately take from water and rinse 3 times, complete the flotation of hollow glass micropearl and cleaning, obtain clean hollow glass micropearl; The NaOH of 20g is added in the deionized water of 1L to the sodium hydroxide solution that preparation mass concentration is 20g/L; Getting clean hollow glass micropearl, to add temperature to be that 80 ℃, mass concentration are in 10g/L sodium hydroxide solution, with the hollow glass micropearl 30min in the speed stir process sodium hydroxide solution of 200rpm, then hollow glass micropearl is fished for out, the hollow glass micropearl of fishing for out with clean deionized water washing, until the pH value of the deionized water after washing is neutrality, complete the pretreatment to hollow glass micropearl; By the hollow glass micropearl drying 2h under 150 ℃ of conditions after filtering;

For 1:8, measure respectively absolute ethyl alcohol and deionized water by volume, absolute ethyl alcohol and deionized water are hybridly prepared into the ethanolic solution of 1L, take the pretreated hollow glass micropearl that drying is crossed, according to 30% of the hollow glass micropearl quality obtaining, take silane KH-550 coupling agent, silane KH-550 coupling agent is dropwise added in absolute ethyl alcohol deionized water mixed solution, first the speed with 200rpm stirs, then with glacial acetic acid, regulating the pH value of mixed solution is 5.5, pretreated hollow glass micropearl is added in coupling modification mixed solution, with 200rpm speed, stir, immersion treatment 8h under 40 ℃ of conditions, carry out after vacuum filtration, hollow glass micropearl after coupling modification is separated from coupling modification mixed solution, hollow glass micropearl after coupling modification is cleaned 3 times with absolute ethyl alcohol, come the hollow glass micropearl after coupling modification is dispersed, be placed under the ultraviolet lamp that dominant wavelength is 365nm and irradiate 30min, then the hollow glass micropearl irradiating through ultraviolet lamp is positioned over to 90 ℃ of preliminary drying 2h, be positioned over again 130 ℃ and bake 1min,

For 1:1.5:30:6, get respectively ferric sulfate, sodium thiosulfate, urea and PEG-6000 in molar ratio, in the deionized water that first ferric sulfate to be added to temperature and be 60 ℃, volume be 1L, adopt sonic oscillation 10min, until ferric sulfate, being dissolved in deionized water is completely after yellow transparent solution, add sodium thiosulfate and fully stir, solution colour becomes pitch black purple, continue to stir and become achromaticity and clarification, now add urea, PEG-6000, continue to stir until solution is white in color colloidal suspension, prepare modified solution; The amidized hollow glass micropearl of rich surface of getting 20g adds in modified solution, and the amidized hollow glass micropearl of rich surface is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution; After sealing stainless steel cauldron, stainless steel cauldron is placed in to homogeneous reactor, with 2 ℃/min speed, be warming up to 180 ℃, isothermal reaction 8h, the naturally cooling rear taking-up of question response still is the hollow glass micropearl of black, utilize the floatability of hollow glass micropearl that hollow glass micropearl is separated with remaining waste liquid after reaction, obtain the hollow glass micropearl after modification; Hollow glass micropearl after modification is first used to deionized water rinsing 3 times, then use absolute ethanol washing 3 times, finally, in 80 ℃ of vacuum drying 24h, obtain clad nano Fe ₃o ₄hollow glass micropearl;

According to volume ratio, be that 1:4 measures respectively deionized water and absolute ethyl alcohol, the deionized water measuring is mixed with absolute ethyl alcohol, make ethanolic solution, re-using mass percent concentration and be 24% ammoniacal liquor, to regulate the pH value of ethanolic solution be 7.8, formation mixed solution; For 1:1.7, measure respectively absolute ethyl alcohol and ethyl orthosilicate by volume, the absolute ethyl alcohol measuring is mixed with ethyl orthosilicate, make ethyl orthosilicate alcohol mixed solution; Take clad nano Fe ₃o ₄hollow glass micropearl, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got the mixed solution of 0.025L, by clad nano Fe ₃o ₄hollow glass micropearl adds in mixed solution, and under 60 ℃ of conditions, the speed stirring 10min with 500r/min, then dropwise adds ethyl orthosilicate alcohol mixed solution, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got 0.04L ethyl orthosilicate alcohol mixed solution, continue to stir 12h, reaction finish the rear floatability of utilizing hollow glass micropearl by its with react remaining fluid separation applications afterwards, by the hollow glass micropearl of separating washed with de-ionized water 3 times, with absolute ethanol washing 3 times, in 80 ℃ of vacuum drying 1h, bake 10min in 150 ℃, obtain coated flower ball-shaped SiO ₂magnetic hollow glass microballoon;

For 1:20:0.006:0.01, get respectively titanium sulfate, urea, polyvinylpyrrolidone and europium nitrate in molar ratio, it is 60 ℃ that titanium sulfate is dissolved in to temperature, volume is in the deionized water of 1L, sonic oscillation 10min, then add successively urea, polyvinylpyrrolidone and europium nitrate, fully stir it is fully dissolved, make modified solution, then add coated flower ball-shaped SiO ₂magnetic hollow glass microballoon, hollow glass micropearl is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution, after sealed reactor, reactor is placed in to homogeneous reactor, with 2 ℃/min speed, be warming up to 160 ℃, isothermal reaction 5h, the reacted hollow glass micropearl of the naturally cooling rear taking-up of question response still, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, with deionized water rinsing 3 times, absolute ethanol washing 3 times, in 80 ℃ of vacuum dryings, obtain rare-earth europium dopen Nano TiO ₂hollow glass micropearl.

Photocatalytic degradation methylene blue dye test result shows, by 0.03g rare-earth europium dopen Nano TiO ₂hollow glass micropearl adds in the methylene blue solution of 50mL, mass concentration 5mg/L, be placed in irradiation under the ultraviolet lamp that is placed on 40W, dominant wavelength 254nm after the 90min of darkroom, light source distance liquid level 10cm, through 8h ultraviolet irradiation, methylene blue dye photocatalytic activity is 99.2%.With VSM multifunction vibration sample magnetic strength instrumentation, determine rare-earth europium dopen Nano TiO ₂the B-H loop of hollow glass micropearl, calculating saturation magnetization is 8.73emu/g.

Embodiment 3

Take the hollow glass micropearl of 15g, add 1L, temperature to and be in the running water of 45 ℃, with 150rpm speed, stir 7min, then running water is warming up to 80 ℃, constant temperature immersion treatment 1h, make it standing until naturally cool to room temperature, after hollow glass micropearl layering, the hollow glass micropearl that swims in running water liquid level upper strata is pulled out, separately take from water and rinse 2 times, complete the flotation of hollow glass micropearl and cleaning, obtain clean hollow glass micropearl; The NaOH of 15g is added in the deionized water of 1L to the sodium hydroxide solution that preparation mass concentration is 15g/L; Getting the clean hollow glass micropearl floatingly selecting, to add temperature to be that 60 ℃, mass concentration are in 15g/L sodium hydroxide solution, with the hollow glass micropearl 20min in the speed stir process sodium hydroxide solution of 150rpm, then hollow glass micropearl is fished for out, the hollow glass micropearl of fishing for out with clean deionized water washing, until the pH value of the deionized water after washing is neutrality, complete the pretreatment to hollow glass micropearl; By the hollow glass micropearl drying 3h under 130 ℃ of conditions after filtering;

According to volume ratio 1:10, measure respectively absolute ethyl alcohol and deionized water, absolute ethyl alcohol and deionized water are hybridly prepared into the ethanolic solution of 1L, get pretreated hollow glass micropearl, according to 20% of the hollow glass micropearl quality obtaining, take aminopropyl triethoxysilane KH-550 coupling agent, aminopropyl triethoxysilane KH-550 coupling agent is dropwise added in the ethanolic solution of preparation, first with 150rpm speed, stir, form mixed solution, then with glacial acetic acid, regulating the pH value of mixed solution is 4.5, obtains coupling modification mixed solution; Pretreated hollow glass micropearl is added in coupling modification mixed solution, with 150rpm speed, stir, immersion treatment 12h under 30 ℃ of conditions, carry out after vacuum filtration, hollow glass micropearl after coupling modification is separated from coupling modification mixed solution, the hollow glass micropearl after coupling modification is cleaned 2 times with absolute ethyl alcohol; Come the hollow glass micropearl after coupling modification is dispersed, be placed under the ultraviolet lamp that dominant wavelength is 365nm and irradiate 40min, 80 ℃ of preliminary drying 3h, 120 ℃ bake 2min;

For 1:0.8:15:3, get respectively ferric sulfate, sodium thiosulfate, urea and PEG-6000 in molar ratio, in the deionized water that first ferric sulfate to be added to temperature and be 45 ℃, volume be 1L, adopt sonic oscillation 7min, until ferric sulfate, being dissolved in deionized water is completely after yellow transparent solution, add sodium thiosulfate and fully stir, solution colour becomes pitch black purple, continue to stir and become achromaticity and clarification, now add urea, PEG-6000, continue to stir until solution is white in color colloidal suspension, prepare modified solution; The amidized hollow glass micropearl of rich surface of getting 15g adds in modified solution, and the amidized hollow glass micropearl of rich surface is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution; After sealing stainless steel cauldron, stainless steel cauldron is placed in to homogeneous reactor, with 1.5 ℃/min speed, be warming up to 160 ℃, isothermal reaction 5h, the naturally cooling rear taking-up of question response still is the hollow glass micropearl of black, utilize the floatability of hollow glass micropearl that hollow glass micropearl is separated with remaining waste liquid after reaction, obtain the hollow glass micropearl after modification; Hollow glass micropearl after modification is first used to deionized water rinsing 2 times, then use absolute ethanol washing 2 times, finally, in 70 ℃ of vacuum drying 18h, obtain clad nano Fe ₃o ₄hollow glass micropearl;

According to volume ratio, be that 1:6 measures respectively deionized water and absolute ethyl alcohol, the deionized water measuring is mixed with absolute ethyl alcohol, make ethanolic solution, re-using mass percent concentration and be 26% ammoniacal liquor, to regulate the pH value of ethanolic solution be 8.2, formation mixed solution; For 1:1.8, measure respectively absolute ethyl alcohol and ethyl orthosilicate by volume, the absolute ethyl alcohol measuring is mixed with ethyl orthosilicate, make ethyl orthosilicate alcohol mixed solution; Take clad nano Fe ₃o ₄hollow glass micropearl, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got the mixed solution of 0.03L, by clad nano Fe ₃o ₄hollow glass micropearl adds in mixed solution, and under 50 ℃ of conditions, the speed stirring 5min with 400r/min, then dropwise adds ethyl orthosilicate alcohol mixed solution, by every gram of clad nano Fe ₃o ₄hollow glass micropearl is got 0.03L ethyl orthosilicate alcohol mixed solution, continue to stir 9h, reaction finish the rear floatability of utilizing hollow glass micropearl by its with react remaining fluid separation applications afterwards, by the hollow glass micropearl of separating washed with de-ionized water 2 times, with absolute ethanol washing 2 times, in 80 ℃ of vacuum drying 2h, 150 ℃ bake 8min, obtain coated flower ball-shaped SiO ₂magnetic hollow glass microballoon;

For 1:10:0.002:0.005, get respectively titanium sulfate, urea, polyvinylpyrrolidone and europium nitrate in molar ratio, it is 60 ℃ that titanium sulfate is dissolved in to temperature, volume is in the deionized water of 1L, sonic oscillation 7min, then add successively urea, polyvinylpyrrolidone and europium nitrate, fully stir it is fully dissolved, make modified solution, then add coated flower ball-shaped SiO ₂magnetic hollow glass microballoon, hollow glass micropearl is transferred in the stainless steel cauldron of inner liner polytetrafluoroethylene together with modified solution, after sealed reactor, reactor is placed in to homogeneous reactor, with 1.5 ℃/min speed, be warming up to 140 ℃, isothermal reaction 4h, the reacted hollow glass micropearl of the naturally cooling rear taking-up of question response still, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, with deionized water rinsing 2 times, absolute ethanol washing 2 times, 70 ℃ of vacuum dryings, obtain rare-earth europium dopen Nano TiO ₂hollow glass micropearl.

Photocatalytic degradation methylene blue dye test result shows, by 0.03g rare-earth europium dopen Nano TiO ₂hollow glass micropearl adds in the methylene blue solution of 50mL, mass concentration 5mg/L, be placed in irradiation under the ultraviolet lamp that is placed on 40W, dominant wavelength 254nm after the 90min of darkroom, light source distance liquid level 10cm, through 8h ultraviolet irradiation, methylene blue dye photocatalytic activity is 92.3%.With VSM multifunction vibration sample magnetic strength instrumentation, determine rare-earth europium dopen Nano TiO ₂the B-H loop of hollow glass micropearl, calculating saturation magnetization is 11.46emu/g.

Claims

1. rare-earth europium dopen Nano TiO ₂the preparation method of hollow glass micropearl, is characterized in that, specifically according to following steps, implements:

Step 1, to hollow glass micropearl clean, flotation and pretreatment;

2. rare-earth europium dopen Nano TiO according to claim 1 ₂the preparation method of hollow glass micropearl, is characterized in that, described step 1 is specifically implemented according to following steps:

3. rare-earth europium dopen Nano TiO according to claim 1 ₂the preparation method of hollow glass micropearl, is characterized in that, described step 2 is specifically implemented according to following steps:

4. rare-earth europium dopen Nano TiO according to claim 1 ₂the preparation method of hollow glass micropearl, is characterized in that, described step 3 is specifically implemented according to following steps:

5. rare-earth europium dopen Nano TiO according to claim 1 ₂the preparation method of hollow glass micropearl, is characterized in that, described step 4 is specifically implemented according to following steps:

6. rare-earth europium dopen Nano TiO according to claim 1 ₂the preparation method of hollow glass micropearl, is characterized in that, described step 5 is specifically implemented according to following steps:

Step 5.3, by sealing after stainless steel cauldron be placed in homogeneous reactor, with 1 ℃/min～2 ℃/min speed, be warming up to 110 ℃～160 ℃, isothermal reaction 2h～5h, after stainless steel cauldron is naturally cooling, utilize the floatation characteristic of hollow glass micropearl that reacted hollow glass micropearl is separated with remaining solution after reaction, the hollow glass micropearl of separating is first used to deionized water rinsing 1 time～3 times, absolute ethanol washing is 1 time～3 times again, finally dry, obtain rare-earth europium dopen Nano TiO ₂magnetic photocatalytic hollow glass micropearl.

7. rare-earth europium dopen Nano TiO according to claim 6 ₂the preparation method of hollow glass micropearl, is characterized in that, in described step 5.3 by the hollow glass micropearl of separating vacuum drying under 60 ℃～80 ℃ conditions.