CN110697784B - Rare earth doped Re y -M x WO 3 Nanoparticles and method for preparing same - Google Patents

Abstract

The invention relates to a rare earth-doped Re _y -M _x WO ₃ nanoparticle and a preparation method thereof, belonging to the fields of new materials and energy conservation and environmental protection. A preparation method of rare earth doped Re _y -M _x WO ₃ nanoparticles, the rare earth salt solution, tungstic acid solution, M salt and inducer are mixed in a solvent to obtain a reaction precursor liquid, and the reaction precursor liquid is 150-400 The reaction is carried out at ℃ for 5-72 hours, and the reacted precipitate is washed with water and alcohol in sequence, and after centrifugal separation, it is dried at 50-80 ℃ to obtain Re _y -M _x WO ₃ powder. The rare earth-doped M _x WO ₃ (Re _y -M _x WO ₃ ) particles of the invention not only have high visible light transmittance and near-infrared shielding/transparent heat shielding functions, but also have excellent photocatalytic degradation of organic pollution object function. The Re _y -M _x WO ₃ particles described in the present invention are particularly suitable for preparing paints and films, etc., which have self-cleaning, air purification, sterilization functions and transparent heat insulation functions at the same time.

Description

A kind of rare earth doped Rey-MxWO3 nanoparticles and preparation method thereof

technical field

The invention relates to a rare earth-doped Re _y -M _x WO ₃ nanoparticle and a preparation method thereof, belonging to the fields of new materials and energy conservation and environmental protection.

Background technique

With the development of society and the improvement of productivity, people's demand for energy is increasing. Due to the large amount of polluting smoke and harmful gases generated in the process of energy consumption, various environmental problems such as greenhouse effect and acid rain are caused. etc. are also increasingly concerned by the whole society. Therefore, energy conservation and consumption reduction are issues that must be considered in the sustainable economic development of various countries. Near-infrared light in the solar spectrum accounts for about 46%. In the energy consumption of many countries, building energy consumption accounts for about 30 to 40% of the national energy consumption, while the energy consumed through glass doors and windows accounts for 50% of building energy consumption. above. Building window glass energy saving and heat preservation is of great significance for energy saving and emission reduction.

At the same time, with the improvement of people's living conditions and the improvement of life quality requirements, people's requirements for their own living environment also increase accordingly. Indoor air quality has gradually become an important area of concern. The fumes from cooking in the kitchen and the formaldehyde emitted from indoor furniture are all invisibly endangering people's health. The window glass of the building occupies most of the area of the building, which is in close contact with the indoor air. If the transparent thermal insulation film coated on the architectural window glass also has the function of photocatalytic degradation of harmful pollutants, the indoor air quality will be greatly improved.

It has been reported in patents that adding M _x WO ₃ particles with transparent thermal insulation properties to coatings can obtain a transparent thermal insulation film that can transmit visible light and shield near-infrared light. Transparent thermal insulation film can be widely used in car film and building door and window film. However, the photocatalytic performance of _{M x} WO particles is not very satisfactory. Therefore, it is very necessary to study and prepare M _x WO ₃ particles with excellent transparent heat shielding function and photocatalytic degradation of organic pollutants.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a rare earth doped M _x WO ₃ (Re _y -M _x WO ₃ ) particle with both transparent heat shielding performance and photocatalytic degradation of organic pollutants and a preparation method thereof, wherein M can be Lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs) or ammonia (NH ₄ ), the rare earth element Re can be lanthanum (La), cerium (Ce), praseodymium (Pr) , neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) , one or more of lutetium (Lu).

The rare earth-doped Re _y -M _x WO ₃ particles of the present invention have a specific surface area of 60-300 m ² /g, a pore volume of 0.1-1.0 cm ³ /g, and an average pore diameter of 10-20 nm, which not only has good visible light transmission and It has the function of near-infrared shielding/transparent heat insulation, and also has the function of photocatalytic degradation of organic pollutants.

A preparation method of rare earth doped Re _y -M _x WO ₃ nanoparticles, the rare earth salt solution, tungstic acid solution, M salt, and inducer are mixed in a solvent to obtain a reaction precursor, and the reaction precursor is 150-400 The reaction was carried out at ℃ for 5-72 hours, and the reacted precipitate was washed with water and alcohol in turn, and after centrifugal separation, it was dried at 50-80 ℃ to obtain Re _y -M _x WO ₃ powder.

The atomic molar ratio of Re:M:W in the reaction precursor is 0.001-1:0.1-0.5:1, the concentration of tungstic acid in the reaction precursor is 0.005-1.5mol/L; the inducer is in the reaction precursor The molar concentration of M is 0.1 to 3.0 mol/L; the M salts are salts of Li, Na, K, Rb, Cs, and NH ₄ .

In the above technical scheme, the reaction precursor solution is configured as follows: measuring a certain volume of rare earth salt solution, weighing M salt and inducer, dissolving them in a solvent, adding rare earth salt solution and mixing evenly, under stirring conditions. The tungstic acid solution is added into it, and the stirring is continued for 1 to 5 hours to obtain a reaction precursor.

In the above technical solution, the drying method includes atmospheric drying, vacuum drying and freeze drying.

Further, the reaction precursor liquid also includes a template agent, the template agent is added to the reaction precursor liquid in the form of a template agent dispersion liquid, and the concentration of the template agent dispersion liquid is 0.001-2 g/mL, and the template agent dispersion liquid is in the reaction. The volume percentage in the precursor solution is 0-50%. In the above technical scheme, the reaction precursor solution is configured as follows: measuring a certain volume of rare earth salt solution, measuring a certain volume of template agent dispersion, weighing M salt and inducer, and dissolving them in a solvent, The rare earth salt solution and the template agent dispersion solution are added, and after mixing uniformly, the tungstic acid solution is added into the solution under stirring conditions, and the stirring is continued for 1-5 hours to obtain a reaction precursor solution.

Further, the templating agent dispersion liquid preferably uses water as a dispersion medium.

Further, the concentration of the rare earth salt solution is 0.001-0.950 mol/L; the tungstate solution is converted into a tungstic acid solution by using a cation exchange resin, and the concentration of the tungstate solution is 0.1-2 mol/L.

Further, the rare earth salt is chloride, nitrate, sulfate, carbonic acid of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. One or more of salts or acetates; or from oxides containing La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu through acid Dissolve the resulting salts.

Further, the M salt is a salt containing Na, K, Rb, Cs, and further, the M salt is an inorganic salt of Na, K, Rb, Cs, such as sulfate, chloride, nitrate , carbonate or acetate, etc.

Further, the M salt is lithium carbonate, lithium sulfate, sodium carbonate, sodium sulfate, potassium carbonate, potassium sulfate, rubidium carbonate, rubidium sulfate, cesium carbonate, cesium sulfate, ammonium carbonate, ammonium bicarbonate or ammonium sulfate.

Further, the template agent is methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, microcrystalline cellulose, natural cellulose, starch, hydroxypropyl cellulose , one or more of sodium carboxymethyl cellulose, hemicellulose, lignin, bacterial cellulose, and commercially available coconut fruit.

Further, the tungstate is one of sodium tungstate, potassium tungstate, ammonium metatungstate, ammonium orthotungstate, and ammonium paratungstate or a mixture thereof.

Further, the solvent is one of water, methanol, ethanol, isopropanol, butanol or a mixture thereof, preferably alcohols or an alcohol-water mixture; wherein, the alcohol-water volume ratio in the alcohol-water mixture is 0.2 ~5:1.

Further, the inducer is oxalic acid, formic acid, tartaric acid, acetic acid, lactic acid, citric acid, ascorbic acid, sorbitol, diethylene glycol, triethylene glycol, tetraethylene glycol, ethylene glycol, polyethylene glycol, sorbic acid, _One or a mixture of polypropylene glycol, potassium _borohydride , _{sodium borohydride} , _aniline , _{acetylacetone} , _N2H4.H2O , _N2H4.HCl , _N2H4.H2SO4 ,

Further, the molar ratio of the inducer to W atom is 0.05-15:1, preferably 1-10:1.

Further, the hydrothermal reaction temperature is preferably 150°C to 300°C, most preferably 180°C to 280°C.

The preparation method of rare earth-doped Re _y -M _x WO ₃ nanoparticles according to the present invention further includes the step of heat treatment, specifically: the obtained Re _y -M _x WO ₃ powder is heated in a reducing atmosphere or an inert atmosphere at a temperature of 200~ Heat treatment at 800℃ for 5min～24h.

Further, the heat treatment temperature is preferably 300-650°C, most preferably 450-600°C, and the heat treatment time is preferably 10-300 min, most preferably 20-180 min.

Further, the reducing atmosphere or inert atmosphere is provided by a single H ₂ , NH ₃ , N ₂ , Ar gas or a mixed gas of any two or more of them.

Further, the reducing atmosphere or inert atmosphere can be obtained by adding organic acids or organic compounds capable of generating reducing gases such as H ₂ , NH ₃ , and CO into the heat treatment reactor.

Another object of the present invention is to provide rare earth doped Re _y -M _x WO ₃ nanoparticles prepared by the above method, the Re _y -M _x WO ₃ composite nanoparticles have a mesoporous hollow structure, y=0.001-0.60 , x=0.2～0.5, the main crystal phase is one or more of hexagonal tungsten bronze M _x WO ₃ , Re=La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, One or more of Er, Tm, Yb, Lu.

Further, the Re _y -M _x WO ₃ nanoparticles have a specific surface area of 20-200 mL/g, a pore volume of 0.1-1.0 m ³ /g, and an average pore diameter of 10-20 nm.

The Re _y -M _x WO ₃ nanoparticles prepared by the above method have near-infrared shielding/transparent heat shielding functions. The Re _y -M _x WO ₃ nanoparticles prepared by the above method have the function of photocatalytic degradation of organic pollutants. The Re _y -M _x WO ₃ powder is used in the preparation of glass transparent thermal insulation coatings, transparent thermal insulation composites, light and heat absorbing coatings, solar collectors, solar water heater coatings, thermal storage composites, heating fibers and light Nanoparticles for thermotherapy have broad application prospects.

The beneficial effects of the present invention are as follows: the rare earth-doped M _x WO ₃ (Re _y -M _x WO ₃ ) particles of the present invention not only have high visible light transmittance and near-infrared shielding/transparent heat shielding functions, but also have Excellent photocatalytic degradation of organic pollutants. This is because the doping of rare earth ions expands the light absorption range of M _x WO ₃ , increases the number of photogenerated electrons, inhibits the recombination of photogenerated electrons and holes, thereby improving the photocatalytic performance of M _x WO ₃ tungsten bronze particles . Therefore, the Re _y -M _x WO ₃ particles described in the present invention are particularly suitable for preparing coatings and films with self-cleaning, air-purifying, sterilizing and transparent and heat-insulating functions at the same time.

Description of drawings

Figure 1 is the XRD patterns of the rare earth doped M _x WO ₃ (Re _y -M _x WO ₃ ) nanoparticles synthesized in Examples 1 to 4 and Comparative Example 1. It can be seen from Figure 1 that the The main crystal phase in the synthesized Re _y -M _x WO ₃ nanoparticles is Cs _0.20 WO ₃ , which is the same as that of Comparative Example 1, indicating that rare earth doping hardly changes the crystal phase composition of M _x WO ₃ .

Fig. 2 is the SEM photo and EDS energy spectrum of the Re _y -M _x WO ₃ nanoparticles synthesized in Example 4 and Comparative Example 1. It can be seen that compared with Comparative Example 1, the Re _y -M _x synthesized in Example 4 The morphology of WO ₃ nanoparticles is more regular and uniform, and the EDS spectrum shows that Re _y -M _x WO ₃ contains Yb, Tm, W, Cs, O and other elements.

Fig. 3 is the ultraviolet-visible-near-infrared transmittance curve of the product particles corresponding to Examples 1-4 and Comparative Example 1 after dispersion of the coated film on the glass surface, it can be seen that the product particles corresponding to Examples 1-4 It has excellent visible light transmission and near-infrared shielding properties.

Figure 4 shows the darkroom adsorption/photocatalytic degradation curves of Rhodamine B by the products corresponding to Examples 1 to 4 and Comparative Example 1. It can be seen that, compared with Comparative Example 1, the Re _y - M _x WO ₃ nanoparticles all have better adsorption/photocatalytic degradation of Rhodamine B, especially, Example 4 has the best photocatalytic degradation effect.

Figure ₅ is the N adsorption-desorption isotherm and pore size distribution curve of Example 4. It can be seen that there is a hysteresis loop in the adsorption isotherm, indicating that the sample has a mesoporous structure; the inset pore size distribution curve shows that the pore size is mainly distributed in 10 nm or so.

Detailed ways

The following non-limiting examples may enable those of ordinary skill in the art to more fully understand the present invention, but do not limit the present invention in any way.

The test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials can be obtained from commercial sources unless otherwise specified.

In the following examples, unless otherwise specified, in the measurement of the performance parameters of the obtained rare earth-doped tungsten bronze nano-powder product:

(1) Use an X-ray diffractometer to test the phase structure of the product. The X-ray diffractometer model is Shimadzu XRD-7000S, Shimadzu Corporation of Japan, using Cu Kα rays, λ=0.15406nm, and the scanning rate is 5°/min. The scanning step size was 0.01°, and the scanning range 2θ was 10°-70°.

(2) Using field emission scanning electron microscope (SEM, JSM-7800F, Japan Electronics Corporation) to characterize the particle size, morphology, agglomeration, etc. of the sample, and test the sample after spraying gold.

(3) Using the module solar cell spectral performance test system (7-SCSpec III, Beijing Saifan Photoelectric Technology Co., Ltd.), test the transmittance curve of the powder dispersion in the 300-1100nm band after coating the glass surface.

(4) Photocatalytic performance test: Using a multifunctional photochemical reactor (Nanjing Stone Electric Equipment Co., Ltd.), the powder was irradiated by a mercury lamp with a power of 300W to carry out the photocatalytic degradation of Rhodamine B. The initial concentration of Rhodamine B was 20×10 ^-6 mol/L. First, 0.2g of powder was added to Rhodamine B solution, and it was left for 50min in a dark room to test its effect on Rhodamine B concentration; Mercury lamp irradiation was used to test its degradation effect on Rhodamine B under this condition. A TU-1810 UV-Vis spectrophotometer (Beijing Puxi General Instrument Co., Ltd.) was used to test its absorbance (Abs) at a wavelength of 554 nm to test the photocatalytic effect of the powder.

(5) The adsorption/desorption isotherms and pore size distribution curves of the samples were measured with SSA-4300 pore size and specific surface area analyzer.

Example 1

Weigh coconut pectin block 75mL, mix coconut palm with 75mL deionized water and crush it to obtain bacterial cellulose dispersion A; Weigh 1g YbCl ₃ 6H ₂ O powder, prepare 0.109mol/L YbCl ₃ Aqueous solution B; Weigh 0.5 g of TmCl ₃ ·6H ₂ O powder to prepare 0.052 mol/L TmCl ₃ aqueous solution C.

6.4651 g of sodium tungstate dihydrate was weighed to prepare a 0.5 mol/L sodium tungstate aqueous solution, and the sodium tungstate solution was ion-exchanged with a strongly acidic styrene cation exchange resin to obtain a tungstic acid solution D. Under stirring conditions, 49 mL of deionized water, 20 mL of dispersion A, 1.4186 g of cesium sulfate, 25.427 g of citric acid, 1.798 mL of solution B and 0.8 μL of solution C were sequentially added to solution D, and stirred for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h, the (Yb,Tm)-Cs _x WO ₃ nanoparticle intermediate was obtained. The prepared (Yb,Tm)-Cs _x WO ₃ nanoparticle intermediates were heat-treated in a tube furnace at 450°C for 30 min in an H ₂ atmosphere to obtain (Yb _0.01 , Tm _0.002 )-Cs _x WO ₃ nanoparticles.

The test results show that the main crystal phase of the prepared ( _{Yb 0.01} , Tm _{0.002 ) -Cs x} WO ₃ nanoparticles is Cs _0.20 WO _{3 .} The visible light transmittance at 1000 nm reaches 65%, the near-infrared light transmittance at 1000 nm is 8%, and the near-infrared shielding rate is 92%; photocatalytic degradation of rhodamine on (Yb _0.01 , Tm _0.002 )-Cs _0.20 WO ₃ nanoparticles In experiment B, the UV lamp irradiation was turned on after adsorption in the dark room for 50 min. The photocatalytic degradation rate of rhodamine B reached 40% when the UV irradiation was performed for 110 min. It shows that the prepared (Yb _0.01 , Tm _0.002 )-Cs _0.20 WO ₃ nanoparticles have better transparent and heat shielding function, and also have certain photocatalytic degradation of organic pollutants.

Example 2

First prepare bacterial cellulose (coconut fruit) dispersion _A , YbCl aqueous solution B and _TmCl aqueous solution C, the preparation process is the same as in Example 1;

6.4651 g of sodium tungstate dihydrate was weighed to prepare a 0.5 mol/L sodium tungstate aqueous solution, and the sodium tungstate solution was ion-exchanged with a strongly acidic styrene cation exchange resin to obtain a tungstic acid solution D. To the tungstic acid solution D under stirring conditions, successively added: 49 mL of deionized water, 20 mL of dispersion A, 1.4186 g of cesium sulfate, 25.427 g of citric acid, 3.596 mL of solution B, and 1.6 μL of solution C, and stirred for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h, obtain (Yb _0.02 , Tm _0.004 )-Cs _x WO ₃ nanoparticle intermediate; the prepared (Yb _0.02 , Tm _0.004 )-Cs _x WO ₃ nanoparticle intermediate is placed in a tube furnace in H ₂ atmosphere Heat treatment at 450° C. for 30 min to obtain (Yb _0.02 , Tm _0.004 )-Cs _x WO ₃ nanoparticles.

The test results show that the main crystal phase of the prepared ( _{Yb 0.02 ,} Tm _0.004 ) _{-Cs x} WO ₃ nanoparticles is Cs _0.20 WO _{3 .} The visible light transmittance at 1000nm is greater than 62%, the near-infrared light transmittance at 1000nm is 10%, and the near-infrared shielding rate is 90%; the photocatalytic degradation of Rhodamine B was carried out on it. The degradation rate of rhodamine B reached 60% under UV irradiation for 110 min. It shows that the prepared (Yb _0.02 , Tm _0.004 )-Cs _0.20 WO ₃ nanoparticles have better transparent and heat-shielding function, and at the same time have a certain function of photocatalytic degradation of organic pollutants.

Example 3

First prepare bacterial cellulose (coconut fruit) dispersion _A , YbCl aqueous solution B and _TmCl aqueous solution C, the preparation process is the same as in Example 1;

6.4651 g of sodium tungstate dihydrate was weighed to prepare a 0.5 mol/L sodium tungstate aqueous solution, and the sodium tungstate solution was ion-exchanged with a strongly acidic styrene cation exchange resin to obtain a tungstic acid solution D. To the tungstic acid solution D under stirring conditions, successively added: 49 mL of deionized water, 20 mL of dispersion A, 1.4186 g of cesium sulfate, 25.427 g of citric acid, 5.396 mL of solution B, and 2.4 μL of solution C, and stirred for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h, to obtain (Yb _0.03 , Tm _0.006 )-Cs _x WO ₃ nanoparticle intermediate; the prepared (Yb _0.03 , Tm _0.006 )-Cs _x WO ₃ nanoparticle intermediate was placed in a tube furnace in a H ₂ atmosphere Heat treatment at 450° C. for 30 min to obtain (Yb _0.03 , Tm _0.006 )-Cs _x WO ₃ nanoparticles.

The test results show that the main crystal phase of the prepared ( _{Yb 0.03 ,} Tm _0.006 ) _{-Cs x} WO ₃ nanoparticles is Cs _0.20 WO _{3 .} The visible light transmittance at 1000nm reaches 67%, the near-infrared light transmittance at 1000nm is 12%, and the near-infrared shielding rate is 88%; the photocatalytic degradation of Rhodamine B was carried out on it. The degradation rate of rhodamine B reached 66% under UV irradiation for 110 min. It shows that the prepared (Yb _0.03 , Tm _0.006 )-Cs _0.20 WO ₃ nanoparticles have both good photocatalytic performance and transparent heat shielding function.

Example 4

First prepare bacterial cellulose (coconut fruit) dispersion _A , YbCl aqueous solution B and _TmCl aqueous solution C, the preparation process is the same as in Example 1;

6.4651 g of sodium tungstate dihydrate was weighed to prepare a 0.5 mol/L sodium tungstate aqueous solution, and the sodium tungstate solution was ion-exchanged with a strongly acidic styrene cation exchange resin to obtain a tungstic acid solution D. To the tungstic acid solution D under stirring conditions, sequentially add: 49 mL of deionized water, 20 mL of dispersion A, 1.4186 g of cesium sulfate, 25.427 g of citric acid, 8.99 mL of solution B, and 4 μL of solution C, and stir for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h, obtain (Yb _0.05 , Tm _0.01 )-Cs _x WO ₃ nanoparticle intermediate; the prepared (Yb _0.05 , Tm _0.01 )-Cs _x WO ₃ nanoparticle intermediate is in a tube furnace in H ₂ atmosphere Heat treatment at 450° C. for 30 min to obtain (Yb _0.05 , Tm _0.01 )-Cs _x WO ₃ nanoparticles.

The test results show that the main crystal phase of the prepared ( _{Yb 0.05} , Tm _{0.01 ) -Cs x} WO ₃ nanoparticles is Cs _0.20 WO _{3 .} The visible light transmittance at 1000nm reaches 65%, the near-infrared light transmittance at 1000nm is 20%, the near-infrared shielding rate is 80%, the near-infrared light transmittance at 1500nm is 7%, and the near-infrared shielding rate reaches 93%; The photocatalytic degradation of rhodamine B was carried out. After adsorption in the dark room for 50 min, the UV lamp was turned on. The degradation rate of rhodamine B reached 60% when the UV irradiation was performed for 110 min. The above data show that the prepared (Yb _0.05 , Tm _0.01 )-Cs _0.20 WO ₃ nanoparticles not only have excellent near-infrared shielding/transparent thermal insulation properties, but also have high photocatalytic properties.

Example 5

First prepare bacterial cellulose (coconut fruit) dispersion _A , YbCl aqueous solution B and _TmCl aqueous solution C, the preparation process is the same as in Example 1;

Weigh 6.4651 g of sodium tungstate dihydrate, prepare a 0.5 mol/L sodium tungstate aqueous solution, and perform ion exchange on the sodium tungstate solution with a strongly acidic styrene cation exchange resin to obtain an equal volume of tungstic acid solution D. To the tungstic acid solution under stirring, add: 49mL deionized water, 20mL dispersion A, 1.4186g cesium sulfate, 25.427g citric acid, _0.109mol /L YbCl aqueous solution 17.98mL solution B, 0.052mol/L solution B TmCl ₃ aqueous solution 8 μL solution C, stirred for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h, obtain (Yb _0.1 , Tm _0.02 )-Cs _x WO ₃ nanoparticle intermediate; the prepared (Yb _0.1 , Tm _0.02 )-Cs _x WO ₃ nanoparticle intermediate is in a tube furnace in H ₂ atmosphere Heat treatment at 450° C. for 30 min to obtain (Yb _0.1 , Tm _0.02 )-Cs _x WO ₃ nanoparticles.

The test results show that the prepared (Yb _0.1 , Tm _0.02 )-Cs _x WO ₃ nanoparticles have a main crystal phase of Cs _0.20 WO ₃ , a mesoporous structure, a specific surface area of 80 m ² /g, and a pore size of about 10 nm. After the glass surface is coated with (Yb _0.1 , Tm _0.02 )-Cs _0.20 WO ₃ film, the visible light transmittance at 560 nm reaches 70%, the near-infrared light transmittance at 1000 nm is 13%, and the near-infrared shielding rate is 87%; The photocatalytic degradation of rhodamine B was carried out. After 50 min of adsorption in the dark room, the UV lamp was turned on, and the degradation rate of rhodamine B reached 75% after 110 min of UV irradiation. It is indicated that the prepared (Yb _0.1 , Tm _0.02 )-Cs _0.20 WO ₃ nanoparticles have both high near-infrared shielding/transparent heat shielding function and photocatalytic function to explain organic pollutants.

Comparative Example 1

Preparation _of pure Cs _x WO nanoparticles without rare earth doping

First prepare bacterial cellulose (coconut fruit) dispersion A, and the preparation process is the same as in Example 1;

Weigh 6.4651 g of sodium tungstate dihydrate, add 39 mL of deionized water to prepare a 0.5 mol/L sodium tungstate aqueous solution, and ion-exchange the sodium tungstate solution with a strongly acidic styrene cation exchange resin to obtain a tungstic acid solution. Add 49 mL of deionized water, 20 mL of dispersion A, 1.4186 g of cesium sulfate, and 25.427 g of citric acid to the tungstic acid solution under stirring, and stir for 2 h;

The reaction precursor solution prepared above was transferred into a 200 mL autoclave, reacted continuously for 3 days at 190 °C, and the reacted precipitate was washed with water and alcohol for 3 times in turn, and after centrifugal separation, dried at 60 °C 10h; heat-treating the prepared Cs _x WO ₃ nanoparticles in a tube furnace at 450° C. in an H ₂ atmosphere for 30 min to obtain Cs _x WO ₃ nanoparticles.

The main crystal phase of the prepared Cs _x WO ₃ nanoparticles is Cs _0.20 WO ₃ , and the photocatalytic degradation of Rhodamine B was carried out on it. After adsorption in a dark room for 50 minutes, the UV lamp was turned on, and the degradation of Rhodamine B under UV radiation for 110 minutes After the glass surface is coated with Cs _0.20 WO ₃ film, the visible light transmittance at 550nm reaches 67%, the near-infrared light transmittance at 1000nm is 11%, and the near-infrared shielding rate is 89%.

Claims (8)

1. a preparation method of rare earth doped Re _y -M _x WO ₃ nanoparticles, it is characterized in that: rare earth salt solution, tungstic acid solution, M salt, inducer are mixed in solvent, obtain reaction precursor liquid, react The precursor solution is reacted at 150-400°C for 5-72 hours, and the reacted precipitate is washed with water and alcohol in turn, and after centrifugal separation, it is dried at 50-80°C to obtain Re _y -M _x WO ₃ powder, The atomic molar ratio of Re:M:W in the reaction precursor is 0.001-1:0.1-0.5:1, the concentration of tungstic acid in the reaction precursor is 0.005-1.5mol/L; the inducer is in the reaction precursor The molar concentration of M is 0.1 to 3.0 mol/L; the M salts are salts of Li, Na, K, Rb, Cs, NH ₄ , and the molar ratio of the inducer to W atoms is 0.05 to 15:1, The Re _y -M _x WO ₃ nanoparticles have a mesoporous hollow structure, y=0.001-0.60, x=0.2-0.5, the main crystal phase is one or more of hexagonal tungsten bronze M _x WO ₃ , Re= Tm and Yb, The reaction precursor liquid also includes a template agent, the template agent is added to the reaction precursor liquid in the form of a template agent dispersion liquid, the concentration of the template agent dispersion liquid is 0.001-2 g/mL, and the template agent dispersion liquid is in the reaction precursor liquid. The volume percentage of 0 to 50%; The template agent is methyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, microcrystalline cellulose, natural cellulose, starch, hydroxypropyl cellulose, carboxymethyl cellulose One or more of sodium cellulose, hemicellulose, lignin, bacterial cellulose, and commercially available coconut fruit; The inducer is oxalic acid, formic acid, tartaric acid, acetic acid, lactic acid, citric acid, ascorbic acid, sorbitol, diethylene glycol, triethylene glycol, tetraethylene glycol, ethylene glycol, polyethylene glycol, sorbic acid, polypropylene glycol, One of potassium borohydride, sodium borohydride, aniline, acetylacetone, N ₂ H ₄ ·H ₂ O, N ₂ H ₄ ·HCl, N ₂ H ₄ ·H ₂ SO ₄ or a mixture thereof. 2. The method according to claim 1, wherein the concentration of the rare earth salt solution is 0.001 to 0.950 mol/L; the tungstate solution is converted into a tungstic acid solution by using a cation exchange resin, and the concentration of the tungstate solution is 0.1～2mol/L. 3. The method according to claim 1 or 2, wherein the rare earth salt is one or more of the chloride, nitrate, sulfate or acetate of Tm and Yb; The oxides of Tm and Yb are salts generated by acid dissolution; the tungstate is one of sodium tungstate, potassium tungstate, ammonium metatungstate, ammonium orthotungstate and ammonium paratungstate or a mixture thereof; The solvent is one of water, methanol, ethanol, isopropanol, butanol or a mixture thereof. 4 . The method according to claim 1 , wherein the method further comprises the step of heat treatment, specifically: subjecting the obtained Re _y -M _x WO ₃ powder to 200-800 ℃ in a reducing atmosphere or an inert atmosphere. 5 . Heat treatment at ℃ for 5min～24h. 5 . The rare earth-doped Re _y -M _x WO ₃ nanoparticles prepared by the method according to any one of claims 1 to 4, wherein the Re _y -M _x WO ₃ nanoparticles have a mesoporous hollow structure, and y= 0.001～0.60, x=0.2～0.5, the main crystal phase is one or more of hexagonal tungsten bronze M _x WO ₃ , Re=Tm and Yb. 6 . The nanoparticle according to claim 5 , wherein the specific surface area of the Re _y -M _x WO ₃ nanoparticle is 20-200 mL/g, the pore volume is 0.1-1.0 m ³ /g, and the average pore volume is 0.1-1.0 m 3 /g. 7 . Diameter 10 ~ 20nm. 7 . The nanoparticle according to claim 5 , wherein the Re _y -M _x WO ₃ nanoparticle has a near-infrared shielding/transparent heat shielding function. 8 . 8 . The nanoparticle according to claim 5 , wherein the Re _y -M _x WO ₃ nanoparticle has the function of photocatalytic degradation of organic pollutants. 9 .

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