Preparation method of high-dispersion-stability photo-thermal conversion functional nano material
阅读说明：本技术 一种高分散稳定性光热转换功能纳米材料的制备方法 (Preparation method of high-dispersion-stability photo-thermal conversion functional nano material ) 是由 方振兴 严洁峰 张发饶 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种高分散稳定性光热转换功能纳米材料的制备方法,包括如下步骤：(1)制备纳米纤维素；(2)制备六氯化钨的醇分散液；(3)将制备好的纳米纤维素加入到六氯化钨的醇分散液中,再加入去离子水,室温搅拌至分散液由淡黄色变成深蓝色；(4)将分散液在≤70℃下搅拌反应6～8 h,得到所述高分散稳定性光热转换功能纳米材料。本发明采用简单回流,以六氯化钨为钨源,纳米纤维素为附载基底,去离子水为氧缺陷诱发剂快速引发氧缺陷的产生,制备出具有高分散稳定性和高光热转换效率的氧化钨与纤维素复合纳米材料。(The invention discloses a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material, which comprises the following steps of: (1) preparing nano cellulose; (2) preparing an alcohol dispersion of tungsten hexachloride; (3) adding the prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue; (4) stirring and reacting the dispersion liquid at the temperature of less than or equal to 70 ℃ for 6-8 h to obtain the high-dispersion-stability photo-thermal conversion functional nano material. According to the invention, the tungsten oxide and cellulose composite nanomaterial with high dispersion stability and high photothermal conversion efficiency is prepared by adopting simple reflux, taking tungsten hexachloride as a tungsten source, nano-cellulose as an attached substrate and deionized water as an oxygen defect inducer to rapidly initiate the generation of oxygen defects.)
1. A preparation method of a high-dispersion-stability photo-thermal conversion functional nano material is characterized by comprising the following steps:
(1) preparing nano cellulose;
(2) preparing an alcohol dispersion of tungsten hexachloride;
(3) adding the prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding deionized water, and stirring until the dispersion liquid is changed from light yellow to dark blue;
(4) stirring and reacting the dispersion liquid at the temperature of less than or equal to 70 ℃ for 6-8 h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
2. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 1, wherein the method for preparing the nanocellulose in the step (1) comprises the following steps: dispersing the qualitative filter paper fragments in a sodium hydroxide aqueous solution to obtain a cellulose dispersion liquid; and (3) carrying out freeze-thaw cycle on the cellulose dispersion liquid for more than three times to obtain the nano-cellulose.
3. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 2, wherein the concentration of the sodium hydroxide aqueous solution is 0.5-1.5 mol/L, and the mass-to-volume ratio of the qualitative filter paper to the sodium hydroxide aqueous solution is 1000mg: 25-35 mL.
4. The method for preparing the nano material with the high dispersion stability and the photothermal conversion function according to claim 2 or 3, wherein the step of freeze-thaw cycle of the cellulose dispersion comprises: and (3) freezing the cellulose dispersion liquid at the temperature of minus 15 to minus 20 ℃ for 4 to 6 hours, taking out after complete freezing, unfreezing at room temperature, and repeating the process for more than three times to obtain the nano-cellulose.
5. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 1, wherein the mass-to-volume ratio of tungsten hexachloride to alcohol solvent in the alcohol dispersion of tungsten hexachloride in the step (2) is 200 mg: 20-40 mL.
6. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 1 or 5, wherein the alcohol solvent in the alcohol dispersion of tungsten hexachloride is selected from one of ethanol, propanol, and n-butanol.
7. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 1, wherein the mass ratio of the nanocellulose and the tungsten hexachloride added in the step (3) is 3-7: 1.
8. The method for preparing the photothermal conversion functional nanomaterial with high dispersion stability according to claim 1 or 7, wherein the volume ratio of the deionized water to the alcohol dispersion of tungsten hexachloride in the step (3) is 1-3: 30.
Technical Field
The invention relates to the technical field of photo-thermal conversion materials, in particular to a preparation method of a nano material with a high dispersion stability and a photo-thermal conversion function.
Background
Research on traditional photothermal conversion nanomaterials mainly focuses on noble metals, carbon nanomaterials and some dyes with infrared absorption characteristics. Because the noble metal is expensive, the reserve is limited and mass production cannot be realized; the photo-thermal conversion efficiency of the carbon nano material is not high; the stability of the dye is poor, and the photobleaching phenomenon is easy to generate. Therefore, the application of these conventional photothermal conversion materials in practical production and life is limited. At present, semiconductors with high carrier concentration, such as copper sulfide, titanium oxide, tungsten oxide, etc., have been the research focus of new photothermal conversion materials due to their abundant reserves, mass production, stable physicochemical properties, high photothermal conversion efficiency, etc. The tungsten oxide crystal can bear a large number of oxygen defects, so that the absorption of visible light and a near infrared region is greatly increased, and the photo-thermal conversion efficiency is improved, and therefore, the application of the defect-state tungsten oxide nano material in the aspect of infrared energy conversion is widely concerned.
At present, methods for preparing defect-state tungsten oxide nano materials mainly comprise an active sputtering method, a pulse laser deposition method, a gas deposition method, an anode plating method, a high vacuum thermal evaporation method, a sol-gel method, a solvothermal method and the like. For example, in the Chinese patent literature, "a tungsten oxide nano gas-sensitive material with multiple surface defects, preparation and application" is disclosed, the publication No. CN106745273B, tungsten hexachloride is used as a tungsten source, and tungsten oxide with rich surface defects is prepared by a solvothermal method.
However, the tungsten oxide nano material prepared in the prior art in the defect state has larger surface energy and tends to agglomerate to form large particles to reduce the surface energy, and the agglomeration of the nano material can greatly increase the recombination probability of semiconductor excitons, which can greatly reduce the photo-thermal conversion performance of the material. Therefore, how to effectively prevent the tungsten oxide nano material from agglomerating is a necessary guarantee for maintaining the photo-thermal stability and moving to practical application.
Disclosure of Invention
The invention provides a preparation method of a high dispersion stability photothermal conversion function nano material, aiming at overcoming the problems that a defect state tungsten oxide nano material prepared in the prior art has larger surface energy and tends to agglomerate to form large particles so as to reduce the surface energy, and the agglomeration of the nano material can greatly increase the recombination probability of semiconductor excitons, so that the photothermal conversion performance of the material is greatly reduced.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano cellulose;
(2) preparing an alcohol dispersion of tungsten hexachloride;
(3) adding the prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding deionized water, and stirring until the dispersion liquid is changed from light yellow to dark blue;
(4) stirring and reacting the dispersion liquid at the temperature of less than or equal to 70 ℃ for 6-8 h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
The invention adopts a low-temperature reflux method, takes tungsten hexachloride as a tungsten source, nanocellulose as a load substrate and deionized water as an oxygen defect inducer to rapidly initiate the generation of oxygen defects, and prepares the tungsten oxide and cellulose composite nanomaterial. The surface of the nano-cellulose is rich in hydroxyl, can be matched with a plurality of transition metal ions and can be used as a template for synthesizing a one-dimensional semiconductor nano-material, so that the nano-cellulose is used as a loading substrate, a natural high polymer material is used as a bridge, tungsten oxide nano-particles can be effectively adsorbed and anchored, the tungsten oxide and cellulose composite nano-material with a one-dimensional nano-structure is formed, the dispersion stability of the tungsten oxide nano-particles is effectively improved, semiconductor exciton recombination caused by agglomeration of the tungsten oxide nano-particles is avoided, and the photo-thermal conversion performance of the material is improved.
In addition, the invention uses the green solvent deionized water as an oxygen defect inducer, can rapidly induce the generation of oxygen defects at room temperature, and has the advantages of low temperature, short time, mild reaction conditions and easy mass production. The preparation process of the invention does not need any surfactant, thereby greatly reducing the production cost and the post-treatment cost.
Preferably, the preparation method of the nanocellulose in the step (1) comprises the following steps: dispersing the qualitative filter paper fragments in a sodium hydroxide aqueous solution to obtain a cellulose dispersion liquid; and (3) carrying out freeze-thaw cycle on the cellulose dispersion liquid for more than three times to obtain the nano-cellulose. The nano-cellulose is prepared by dissociation of qualitative filter paper, the raw materials are cheap and easy to obtain, and the production cost is greatly reduced.
Preferably, the concentration of the sodium hydroxide aqueous solution is 0.5-1.5 mol/L, and the mass-volume ratio of the qualitative filter paper to the sodium hydroxide aqueous solution is 1000mg: 25-35 mL.
Preferably, the step of freeze-thaw cycling of the cellulose dispersion is: and (3) freezing the cellulose dispersion liquid at the temperature of-15 to-20 ℃ for 4-6 h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for more than three times to obtain the nano-cellulose.
Preferably, the mass-to-volume ratio of tungsten hexachloride to alcohol solvent in the alcohol dispersion of tungsten hexachloride in step (2) is 200 mg: 20-40 mL.
Preferably, the alcohol solvent in the alcohol dispersion liquid of tungsten hexachloride is selected from one of ethanol, propanol, isopropanol and n-butanol.
Preferably, the mass ratio of the nanocellulose and the tungsten hexachloride added in the step (3) is 3-7: 1.
preferably, the volume ratio of the deionized water added in the step (3) to the alcohol dispersion liquid of tungsten hexachloride is 1-3: 30.
Therefore, the invention has the following beneficial effects:
(1) the nano-cellulose is used as a loading substrate, so that the tungsten oxide nano-particles can be effectively adsorbed and anchored to form the tungsten oxide and cellulose composite nano-material with a one-dimensional nano-structure, the dispersion stability of the tungsten oxide nano-particles is effectively improved, semiconductor exciton recombination caused by agglomeration of the tungsten oxide nano-particles is avoided, and the photo-thermal conversion performance of the material is improved;
(2) the green solvent deionized water is used as an oxygen defect inducer, the generation of oxygen defects can be rapidly initiated at room temperature, the temperature is low, the time is short, the reaction condition is mild, and the mass production is easy;
(3) the preparation process does not need any surfactant, thereby greatly reducing the production cost and the post-treatment cost.
Drawings
Fig. 1 is an XRD pattern of the photothermal conversion functional nanomaterial prepared in example 1.
Fig. 2 is an XRD pattern of the photothermal conversion functional nanomaterial prepared in example 6.
Fig. 3 is an XRD pattern of the photothermal conversion functional nanomaterial prepared in comparative example 2.
Fig. 4 is an XRD pattern of the photothermal conversion functional nanomaterial prepared in comparative example 3.
FIG. 5 is a temperature-rising effect curve of the photothermal conversion functional nanomaterial prepared in example 1 under 980nm infrared laser irradiation.
Fig. 6 is a temperature increase effect curve of the photothermal conversion functional nanomaterials prepared in examples 1, 4 and 5 under 980nm infrared laser irradiation.
Detailed Description
The invention is further described with reference to the following detailed description and accompanying drawings.
Example 1:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 1mL of deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
Example 2:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 2mL of deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
Example 3:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 3mL of deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
Example 4:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 35mL of 0.5mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator with the temperature of-15 ℃ for freezing for 6h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 40mL of propanol to obtain an alcohol dispersion liquid of tungsten hexachloride;
(3) 1400mg of prepared nano-cellulose is added into alcohol dispersion liquid of tungsten hexachloride, 1mL of deionized water is added, and the mixture is stirred at 70 ℃ until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
Example 5:
a preparation method of a high-dispersion-stability photo-thermal conversion functional nano material comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 25mL of 1.5mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at the temperature of-20 ℃ for freezing for 4h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 20mL of butanol to obtain an alcohol dispersion liquid of tungsten hexachloride;
(3) adding 600mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 1mL of deionized water, and stirring at 70 ℃ until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 60 ℃ for 6h to obtain the high-dispersion-stability photo-thermal conversion functional nano material.
Example 6:
a preparation method of a nano material with a photothermal conversion function comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 1mL of deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue;
(4) and stirring the dispersion liquid at room temperature for 6 hours to obtain the photothermal conversion functional nano material.
Comparative example 1 (without nanocellulose addition):
a preparation method of a nano material with a photothermal conversion function comprises the following steps:
(1) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(2) adding 1mL of deionized water into the dispersion, and stirring at room temperature until the dispersion turns into dark blue from light yellow;
(3) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the photothermal conversion functional nano material.
Comparative example 2 (water addition too much):
a preparation method of a nano material with a photothermal conversion function comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 5mL of deionized water, and stirring at room temperature until the dispersion liquid is changed into dark blue from light yellow, and then is changed into blue-green;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the photothermal conversion functional nano material.
Comparative example 3 (with too little water added):
a preparation method of a nano material with a photothermal conversion function comprises the following steps:
(1) preparing nano-cellulose: dispersing 1000mg of qualitative filter paper fragments into 30mL of 1mol/L sodium hydroxide aqueous solution to obtain cellulose dispersion liquid; placing the cellulose dispersion liquid in a freezing refrigerator at-18 ℃ for freezing for 5h, taking out after completely freezing, unfreezing at room temperature, and repeating the process for four times to obtain nano-cellulose;
(2) preparation of alcoholic dispersion of tungsten hexachloride: dispersing 200mg of tungsten hexachloride in 30mL of ethanol to obtain an alcohol dispersion liquid of the tungsten hexachloride;
(3) adding 1000mg of prepared nano-cellulose into alcohol dispersion liquid of tungsten hexachloride, adding 0.1mL of deionized water, and stirring at room temperature until the dispersion liquid is changed from light yellow to dark blue;
(4) and refluxing the dispersion liquid at 70 ℃ for 6h to obtain the photothermal conversion functional nano material.
XRD tests were performed on the photothermal conversion functional nanomaterials prepared in the above examples and comparative examples, and the results are shown in fig. 1 to 4. As can be seen from the broad diffraction peak in FIG. 1, the nano-material prepared in example 1 by refluxing reaction at 70 ℃ is the orthorhombic phase WO3·H2O; as can be seen from FIG. 2, the reaction in example 6 at room temperature gave an amorphous structure without formation of crystals; the sharp diffraction peaks in fig. 3 illustrate that the addition of too much deionized water in comparative example 2, outside the scope of the present invention, increases the crystallinity of the product and increases the crystal size; as can be seen from FIG. 4, in comparative example 3, too little deionized water was added, and the crystal configuration of the resulting product was significantly changed from that of orthorhombic hydrated tungsten oxideChanged into a monoclinic phase W18O49。
The photothermal conversion functional nanomaterials prepared in the above examples and comparative examples were left to stand for 24 hours, and dispersion stability thereof was tested, with the results shown in table 1.
Table 1: dispersion stability test results.
As can be seen from table 1, the photothermal conversion functional nanomaterial prepared by the method of the present invention in examples 1 to 6 has good dispersion stability, while the nanocellulose is not added during the preparation in comparative example 1, and the crystal size and the crystal configuration are changed in comparative examples 2 and 3, which have significant effects on the dispersion stability of the photothermal conversion functional nanomaterial prepared.
The photothermal conversion functional nanomaterial prepared in the above example was irradiated with 980nm infrared light, and a temperature point was recorded every 30 seconds in a closed system. When the closed system reached the equilibrium temperature, the infrared laser power was turned off, and the data was recorded every 15 seconds to evaluate the photothermal conversion effect of the obtained nanomaterial, and the results are shown in fig. 5 and 6. As can be seen from FIG. 5, the temperature of the alcohol solvent is not substantially changed under the irradiation of the laser, which shows that the alcohol solvent has no thermal response signal to 980nm infrared light; the nano material prepared by the invention generates obvious temperature rise effect under the laser irradiation of the wavelength, and the temperature rise effect is more obvious along with the increase of the laser power. As can be seen from fig. 6, the amount of the nanocellulose added may affect the photothermal conversion effect of the finally prepared nanomaterial.