A composite material of bismuth oxychloride and neodymium-doped aluminum phosphate and a preparation method and application thereof

Abstract

This application relates to the field of new materials technology, specifically to a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate, its preparation method, and its application. The composite material is composed of bismuth oxychloride and neodymium-doped aluminum phosphate. The bismuth oxychloride and neodymium-doped aluminum phosphate composite material of this invention possesses both photocatalytic and radiative cooling functions, exhibiting a significant synergistic effect.

Description

Technical Field

[0001] This application relates to the field of new materials technology, specifically to a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate, its preparation method and application, and in particular to a bismuth oxychloride-neodymium-doped aluminum phosphate composite material that simultaneously possesses photocatalytic degradation of pollutants and efficient radiative cooling functions, its preparation method and application. Background Technology

[0002] In the face of a escalating global energy crisis and environmental pollution, developing efficient, sustainable, and environmentally friendly energy utilization and energy-saving technologies has become a key task in the scientific research field. Photocatalysis and radiation refrigeration technologies, as two highly promising green technologies, are receiving widespread attention.

[0003] Photocatalysis is a technology that utilizes photocatalysts to convert light energy into chemical energy under illumination, driving a series of chemical reactions to achieve purposes such as pollutant degradation, water splitting for hydrogen production, and carbon dioxide reduction. Traditional photocatalysts, such as titanium dioxide (TiO2), exhibit good photocatalytic activity in the ultraviolet region. However, ultraviolet light only accounts for about 5% of the solar spectrum, leaving most of the visible and near-infrared light unutilized, which significantly limits their photocatalytic efficiency and application range. Furthermore, many photocatalysts suffer from complex preparation processes, high costs, and poor stability, making it difficult to meet the demands of large-scale practical applications. Therefore, the search for novel photocatalysts with broad spectral response, high activity, high stability, and low cost has become a research hotspot in the field of photocatalysis.

[0004] Radiative cooling technology is a passive cooling method that lowers the temperature of an object by radiating specific wavelengths of infrared light into space through the surface of the material, while simultaneously reflecting visible and near-infrared light from sunlight. Compared to traditional mechanical cooling, radiative cooling requires no electrical energy and has significant advantages such as zero energy consumption and no pollution, showing great application potential in areas such as building energy conservation, heat dissipation of electronic equipment, and outdoor products. Currently, research on radiative cooling materials mainly focuses on how to improve the reflectivity of materials to sunlight and their infrared emissivity in the atmospheric window band. However, existing radiative cooling materials often have only one function, possessing only radiative cooling properties and unable to simultaneously achieve other functions, such as photocatalytic degradation of pollutants, which to some extent limits their comprehensive application value.

[0005] Bismuth oxychloride (BiOCl), as a layered semiconductor material, shows potential in photocatalysis due to its unique crystal and electronic structures. However, bismuth oxychloride alone suffers from high photogenerated carrier recombination rates and weak visible light absorption, hindering further improvement in its photocatalytic efficiency. Aluminum phosphate (AlPO4) possesses good chemical and thermal stability and has applications in adsorption and catalysis, but research on its photocatalytic and radiative cooling properties is relatively limited. Current photocatalytic and radiative cooling materials each have their limitations, making it difficult to meet increasingly diverse application demands. Therefore, developing a novel material with both highly efficient photocatalytic and radiative cooling capabilities has significant practical importance and application value. Summary of the Invention

[0006] In a first aspect, the present invention provides a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate. The composite material is composed of bismuth oxychloride and neodymium-doped aluminum phosphate.

[0007] Preferably, the molar ratio of bismuth oxychloride to neodymium-doped aluminum phosphate is 1:1 to 3:1, and the molar ratio of aluminum to neodymium in neodymium-doped aluminum phosphate is 1:0.01 to 1:0.03.

[0008] Secondly, the present invention provides a method for preparing a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate. The preparation method includes the following steps: S1. Neodymium nitrate or its hydrate is mixed with an aqueous solution of aluminum nitrate at a molar ratio of aluminum to neodymium of 1:0.01 to 1:0.03 to obtain solution A; S2. While continuously stirring, add the aqueous solution of ammonium dihydrogen phosphate to solution A, continue stirring and mixing until homogeneous, and adjust the pH of the solution to 6-8 to obtain solution B; S3. Transfer solution B to a high-pressure reactor and react at 120~150℃ for 6~12 h. After the reaction is complete, cool naturally to room temperature, collect the precipitate by centrifugation, wash and dry it, and then calcine it at 300~500℃ for 2~4 h to obtain neodymium-doped aluminum phosphate, denoted as powder C. S4. Mix powder C with bismuth nitrate solution until homogeneous. The molar ratio of bismuth nitrate to aluminum nitrate used to prepare neodymium-doped aluminum phosphate is 1:1 to 3:1. Then adjust the pH of the solution to 6 to 8 to obtain solution D. S5. Transfer solution D to a high-pressure reactor, place the reactor in a microwave-assisted hydrothermal synthesis device, set the reaction temperature to 160~180℃, and the reaction time to 12~24 h. After the reaction is completed, allow the reactor to cool naturally to room temperature, centrifuge the reaction solution, collect the precipitate, and after washing and drying, obtain the composite material of bismuth oxychloride and neodymium-doped aluminum phosphate.

[0009] Preferably, in step S1, 5-10 g of aluminum nitrate is weighed and dissolved in 50-100 mL of deionized water to obtain an aqueous solution of aluminum nitrate.

[0010] Preferably, in step S1, the mixture is stirred on a magnetic stirrer at a speed of 200-500 r / min for 30-60 min.

[0011] Preferably, in step S2, 3-7 g of ammonium dihydrogen phosphate is weighed and dissolved in 50-100 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate.

[0012] Preferably, in step S3, the washed precipitate is dried at 60-80 °C for 8-12 h.

[0013] Preferably, in step S4, bismuth nitrate and 0.5-2 mol / L (e.g., 1 mol / L) HCl are added to 70-100 mL of deionized water in a molar ratio of 1:1 to 3:1, and stirred for 1-2 h to form a bismuth nitrate solution.

[0014] Preferably, in step S5, the washed precipitate is dried at 60~100℃ for 6~8 h.

[0015] Thirdly, the present invention provides the application of the aforementioned bismuth oxychloride and neodymium-doped aluminum phosphate composite material in the preparation of photocatalysts.

[0016] Fourthly, the present invention provides the application of the aforementioned bismuth oxychloride and neodymium-doped aluminum phosphate composite material in the preparation of formulations with dual functions of photodegradation and radiation cooling.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The bismuth oxychloride and neodymium-doped aluminum phosphate composite material of this invention exhibits outstanding photocatalytic performance. Upon illumination, it rapidly generates highly active photogenerated electron-hole pairs, quickly decomposing organic pollutants such as formaldehyde and organic dyes in air and water. Compared to traditional materials, the degradation efficiency is significantly improved, enabling faster improvement of environmental quality and providing an efficient and green means for environmental governance.

[0018] The bismuth oxychloride and neodymium-doped aluminum phosphate composite material of this invention possesses excellent radiative cooling capabilities. During the day, under direct sunlight, it can efficiently radiate mid-infrared heat and reflect most of the sunlight, achieving cooling for itself and its surrounding environment. When applied to building exterior walls or roofs, it can significantly reduce air conditioning usage, lower building energy consumption and operating costs, and help alleviate the energy crisis and address climate change.

[0019] The bismuth oxychloride and neodymium-doped aluminum phosphate composite material of this invention possesses both photocatalytic and radiative cooling functions, exhibiting a significant synergistic effect. When used in outdoor facilities, it provides self-cleaning and cooling, extending its service life; in agricultural greenhouses, it degrades harmful gases and regulates temperature, creating an optimal environment for crop growth. Therefore, the composite material of this invention provides high-quality materials and technical support for innovative development in multiple fields, with a very broad application prospect. Attached Figure Description

[0020] Figure 1 The image shows the XRD pattern of BiOCl / Nd-AlPO4 prepared in Example 1.

[0021] Figure 2 This is a SEM image of BiOCl / Nd-AlPO4 prepared in Example 1.

[0022] Figure 3 The degradation rate curve of Rhodamine B by BiOCl / Nd-AlPO4 prepared in Example 1 is shown.

[0023] Figure 4 The curves show the radiative cooling of BiOCl / Nd-AlPO4 prepared in Example 1.

[0024] Figure 5 This is the XPS full spectrum of BiOCl / Nd-AlPO4 prepared in Example 1. Detailed Implementation

[0025] The present invention is further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0026] This invention aims to develop a material that combines bismuth oxychloride with neodymium-doped aluminum phosphate, enabling it to simultaneously possess efficient photocatalytic and radiative cooling capabilities. This overcomes the limitations of single-material functionality, broadens application scenarios, and provides innovative solutions for environmental governance, energy conservation, and cooling, thereby promoting green and sustainable development.

[0027] Weigh 5-10 g of aluminum nitrate and dissolve it in 50-100 mL of deionized water to obtain an aluminum nitrate aqueous solution. Add neodymium nitrate to the aluminum nitrate aqueous solution at a molar ratio of aluminum to neodymium of 1:0.01-1:0.03, and stir on a magnetic stirrer at a speed of 200-500 r / min for 30-60 min to obtain solution A.

[0028] Weigh 3-7 g of ammonium dihydrogen phosphate and dissolve it in 50-100 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate. While continuously stirring, slowly add the aqueous solution of ammonium dihydrogen phosphate dropwise to solution A, controlling the dropping rate at 5-10 mL per minute. After the addition is complete, continue stirring for 1-2 hours. Adjust the pH of the solution to 6-8 with 0.5-2 mol / L (e.g., 1 mol / L) ammonia water to obtain solution B.

[0029] Solution B was transferred to a high-pressure reactor lined with polytetrafluoroethylene and reacted at 120–150 °C for 6–12 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the precipitate was collected by centrifugation. The precipitate was washed 3–5 times alternately with deionized water and ethanol. The washed precipitate was dried at 60–80 °C for 8–12 h and then placed in a muffle furnace and calcined at 300–500 °C for 2–4 h to obtain powder C (neodymium-doped aluminum phosphate).

[0030] Bismuth nitrate and 0.5–2 mol / L (e.g., 1 mol / L) HCl were added to 70–100 mL of deionized water in a molar ratio of 1:1 to 3:1, and stirred for 1–2 h to form a bismuth nitrate solution. Neodymium-doped aluminum phosphate (powder C) was then added to the bismuth nitrate solution, with a bismuth-aluminum molar ratio of bismuth nitrate to aluminum nitrate used in the preparation of neodymium-doped aluminum phosphate of 1:1 to 3:1. The pH of the solution was then adjusted to 6–8 using 0.5–2 mol / L (e.g., 1 mol / L) ammonia water to obtain solution D.

[0031] Solution D was transferred to a high-pressure reactor lined with polytetrafluoroethylene (PTFE), and the reactor was placed in a microwave-assisted hydrothermal synthesis apparatus. The reaction temperature was set to 160–180 °C, and the reaction time was 12–24 h. After the reaction was completed, the reactor was allowed to cool naturally to room temperature. The reaction solution was then centrifuged, and the precipitate was collected. The precipitate was washed 3–5 times alternately with deionized water and ethanol. The washed precipitate was then dried in a drying oven at 60–100 °C for 6–8 h to finally obtain a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate.

[0032] The composite material of bismuth oxychloride and neodymium-doped aluminum phosphate can be used as a photocatalyst. For example, the composite material can be used in LED lamps to simulate sunlight degradation of organic dyes. These organic dyes include, but are not limited to, methyl orange or rhodamine B.

[0033] The composite material of bismuth oxychloride and neodymium-doped aluminum phosphate can also be used for dye wastewater treatment. Under visible light irradiation, the composite material of bismuth oxychloride and neodymium-doped aluminum phosphate can photocatalytically degrade organic dyes in dye wastewater.

[0034] Before conducting radiation cooling tests, a coating sample needs to be prepared. Weigh 0.125~0.375 g of polyvinylidene fluoride, 0.765~2.295 g of a composite material of bismuth oxychloride and neodymium-doped aluminum phosphate, and 3~5 mL of N-methylpyrrolidone. Mix and stir the three components for 6~8 h. Then, use a spatula to coat the solution onto aluminum foil and dry it in an oven at 70~90℃ for 40~60 min to obtain the final coating.

[0035] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0036] Example 1 The preparation method of bismuth oxychloride / neodymium-doped aluminum phosphate composite material includes the following steps: (1) Weigh 5 g of aluminum nitrate and dissolve it in 50 mL of deionized water to obtain an aqueous solution of aluminum nitrate. Add neodymium nitrate to the aqueous solution of aluminum nitrate at a molar ratio of 1:0.01 and stir on a magnetic stirrer at a speed of 200 r / min for 30 min to obtain solution A.

[0037] (2) Weigh 3 g of ammonium dihydrogen phosphate and dissolve it in 50 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate. Under continuous stirring, slowly add the aqueous solution of ammonium dihydrogen phosphate to solution A, controlling the dropping rate to 5 mL per minute. After the addition is complete, continue stirring for 1 h, and adjust the pH of the solution to 6 with 1 mol / L ammonia water to obtain solution B.

[0038] (3) Transfer solution B to a high-pressure reactor lined with polytetrafluoroethylene and react at 120°C for 6 h. After the reaction is complete, cool naturally to room temperature, collect the precipitate by centrifugation, wash it three times alternately with deionized water and ethanol, dry the washed precipitate at 60°C for 8 h, and then place it in a muffle furnace and calcine at 300°C for 2 h to obtain powder C.

[0039] (4) Bismuth nitrate and 1 mol / L HCl were added to 70 mL of deionized water at a molar ratio of 1:1 and stirred for 1 h to form a bismuth nitrate solution. Powder C was then added to the bismuth nitrate solution. The molar ratio of bismuth nitrate to aluminum nitrate used to prepare neodymium-doped aluminum phosphate was 1:1. The pH of the solution was then adjusted to 6 using 1 mol / L ammonia water to obtain solution D.

[0040] (5) Transfer solution D to a high-pressure reactor lined with polytetrafluoroethylene, and place the reactor in a microwave-assisted hydrothermal synthesis apparatus. Set the reaction temperature to 160℃ and the reaction time to 12 h. After the reaction is complete, allow the reactor to cool naturally to room temperature, centrifuge the reaction solution, and collect the precipitate. Wash the precipitate three times alternately with deionized water and ethanol. Place the washed precipitate in a drying oven at 60℃ and dry for 6 h to finally obtain the bismuth oxychloride / neodymium-doped aluminum phosphate composite material.

[0041] Coating sample preparation: Weigh 0.125 g of polyvinylidene fluoride, 0.765 g of bismuth oxychloride / neodymium-doped aluminum phosphate composite material, and 3 mL of N-methylpyrrolidone. Mix and stir the three together for 6 h. Then, use a scraper to coat the solution onto an aluminum foil with a length of 6 cm, a width of 6 cm, and a thickness of 0.2 mm. Dry in an oven at 70 °C for 40 min to obtain the final coating.

[0042] Example 2

[0043] The preparation method of bismuth oxychloride / neodymium-doped aluminum phosphate composite material includes the following steps: (1) Weigh 7 g of aluminum nitrate and dissolve it in 75 mL of deionized water to obtain an aluminum nitrate aqueous solution. Add neodymium nitrate to the aluminum nitrate aqueous solution at a molar ratio of aluminum to neodymium of 1:0.02. Stir the solution on a magnetic stirrer at a speed of 350 r / min for 45 min to obtain solution A.

[0044] (2) Weigh 5 g of ammonium dihydrogen phosphate and dissolve it in 75 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate. Under continuous stirring, slowly add the aqueous solution of ammonium dihydrogen phosphate to solution A, controlling the dropping rate to 7 mL per minute. After the addition is complete, continue stirring for 1.5 h, and adjust the pH of the solution to 7 with 1 mol / L ammonia water to obtain solution B.

[0045] (3) Transfer solution B to a high-pressure reactor lined with polytetrafluoroethylene and react at 135℃ for 9 h. After the reaction is complete, cool naturally to room temperature, collect the precipitate by centrifugation, wash it 4 times with deionized water and ethanol alternately, dry the washed precipitate at 70℃ for 10 h, and then place it in a muffle furnace and calcine at 400℃ for 3 h to obtain powder C.

[0046] (4) Bismuth nitrate and 1 mol / L HCl were added to 85 mL of deionized water at a molar ratio of 2:1 and stirred for 1.5 h to form a bismuth nitrate solution. Then, powder C was added to the bismuth nitrate solution. The molar ratio of bismuth nitrate to aluminum nitrate used to prepare neodymium-doped aluminum phosphate was 2:1. The pH of the solution was then adjusted to 7 using 1 mol / L ammonia water to obtain solution D.

[0047] (5) Transfer solution D to a high-pressure reactor lined with polytetrafluoroethylene, and place the reactor in a microwave-assisted hydrothermal synthesis apparatus. Set the reaction temperature to 170℃ and the reaction time to 18 h. After the reaction is complete, allow the reactor to cool naturally to room temperature, centrifuge the reaction solution, and collect the precipitate. Wash the precipitate four times alternately with deionized water and ethanol. Place the washed precipitate in an 80℃ drying oven and dry for 7 h to finally obtain the bismuth oxychloride / neodymium-doped aluminum phosphate composite material.

[0048] Coating sample preparation: Weigh 0.25 g of polyvinylidene fluoride, 1.53 g of bismuth oxychloride / neodymium-doped aluminum phosphate composite material, and 4 mL of N-methylpyrrolidone. Mix and stir the three together for 7 h. Then, use a scraper to coat the solution onto an aluminum foil with a length of 6 cm, a width of 6 cm, and a thickness of 0.2 mm. Dry in an oven at 80 °C for 50 min to obtain the final coating.

[0049] Example 3

[0050] The preparation method of bismuth oxychloride / neodymium-doped aluminum phosphate composite material includes the following steps: (1) Weigh 10 g of aluminum nitrate and dissolve it in 100 mL of deionized water to obtain an aluminum nitrate aqueous solution. Add neodymium nitrate to the aluminum nitrate aqueous solution at a molar ratio of aluminum to neodymium of 1:0.03. Stir the solution on a magnetic stirrer at a speed of 500 r / min for 60 min to obtain solution A.

[0051] (2) Weigh 7 g of ammonium dihydrogen phosphate and dissolve it in 100 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate. Under continuous stirring, the aqueous solution of ammonium dihydrogen phosphate is slowly added dropwise to solution A, and the dropping rate is controlled at 10 mL per minute. After the addition is completed, continue stirring for 2 h, and adjust the pH of the solution to 8 with 1 mol / L ammonia water to obtain solution B.

[0052] (3) Transfer solution B to a high-pressure reactor lined with polytetrafluoroethylene and react at 150°C for 12 h. After the reaction is complete, cool naturally to room temperature, collect the precipitate by centrifugation, wash it 5 times alternately with deionized water and ethanol, dry the washed precipitate at 80°C for 12 h, and then place it in a muffle furnace and calcine at 500°C for 4 h to obtain powder C.

[0053] (4) Bismuth nitrate and 1 mol / L HCl were added to 100 mL of deionized water at a molar ratio of 3:1 and stirred for 2 h to form a bismuth nitrate solution. Then powder C was added to the bismuth nitrate solution. The molar ratio of bismuth nitrate to aluminum nitrate used to prepare neodymium-doped aluminum phosphate was 3:1. The pH of the solution was then adjusted to 8 using 1 mol / L ammonia water to obtain solution D.

[0054] (5) Transfer solution D to a high-pressure reactor lined with polytetrafluoroethylene, and place the reactor in a microwave-assisted hydrothermal synthesis apparatus. Set the reaction temperature to 180℃ and the reaction time to 24 h. After the reaction is complete, allow the reactor to cool naturally to room temperature, centrifuge the reaction solution, and collect the precipitate. Wash the precipitate five times alternately with deionized water and ethanol. Place the washed precipitate in a drying oven at 100℃ and dry for 8 h to finally obtain the bismuth oxychloride / neodymium-doped aluminum phosphate composite material.

[0055] Coating sample preparation: Weigh 0.375 g of polyvinylidene fluoride, 2.295 g of bismuth oxychloride / neodymium-doped aluminum phosphate composite material, and 5 mL of N-methylpyrrolidone. Mix and stir the three together for 8 h. Then, use a scraper to coat the solution onto an aluminum foil with a length of 6 cm, a width of 6 cm, and a thickness of 0.2 mm. Dry in an oven at 90 ℃ for 60 min to obtain the final coating.

[0056] Figure 1 This is the XRD pattern of the BiOCl / Nd-AlPO4 prepared in Example 1. As shown in the figure, the main diffraction peaks of the BiOCl / Nd-AlPO4 composite material are basically consistent with the BiOCl standard card (PDF#06-0249), indicating that the BiOCl crystalline phase was successfully formed in the sample. Sharp diffraction peaks appear at approximately 22°, 25°, and 32°, indicating that BiOCl has good crystallinity. Furthermore, some weaker diffraction peaks in the pattern correspond to the AlPO4 standard card (PDF#47-0599), indicating that the AlPO4 component was successfully introduced into the composite material. At the same time, no obvious impurity peaks were observed in the figure, indicating that no other impurity phases were generated during the composite process, and the resulting material has high purity. The coexistence of BiOCl and Nd-AlPO4 phases indicates that the BiOCl / Nd-AlPO4 composite material has been successfully constructed. The XRD pattern shows that neodymium doping shifts the aluminum phosphate peaks compared to the PDF card, proving that neodymium doping has entered the aluminum phosphate lattice.

[0057] Figure 2 This is a SEM image of the BiOCl / Nd-AlPO4 prepared in Example 1. The SEM results show that the sample exhibits a regular sheet-like / structure with a large number of fine particles uniformly loaded on its surface, indicating that the composite component has successfully adhered to the surface of the host material. This structure can provide more active sites and promote interfacial charge transport, which is beneficial for improving the photocatalytic performance of the material.

[0058] Figure 3This is the degradation rate curve of Rhodamine B by BiOCl / Nd-AlPO4 prepared in Example 1. A certain amount of catalyst was weighed and added to the target pollutant Rhodamine B solution, and then sonicated to ensure uniform dispersion. The solution was then stirred in the dark for approximately 30 minutes to reach adsorption-desorption equilibrium. Afterwards, the light source was turned on to initiate the photocatalytic reaction, and samples were taken at 20-minute intervals. The samples were centrifuged, and the intensity of the characteristic absorption peak of the supernatant was measured using a UV-Vis spectrophotometer. The pollutant concentration change was calculated based on the absorbance change, and the relative concentration of the pollutant was expressed as C / C0 to evaluate the degradation efficiency. Simultaneously, the reaction kinetics were analyzed using a pseudo-first-order kinetic model: ln(C / C0) = kt, where k is the apparent reaction rate constant.

[0059] As shown in the figure, the pollutant concentration gradually decreases with increasing reaction time, and the rate of decrease is relatively fast in the initial stage, indicating that the sample has high photocatalytic activity. Subsequently, the reaction rate gradually slows down and tends to stabilize, indicating that the system gradually approaches an equilibrium state.

[0060] Figure 4 This is the radiation cooling curve of BiOCl / Nd-AlPO4 prepared in Example 1. The radiation cooling curve of BiOCl / Nd-AlPO4 on aluminum foil was obtained. Outdoor natural light conditions were used. The sample was placed on the aluminum foil, and the surface temperature change of the sample was monitored in real time using thermocouples, while ambient temperature and other parameters were recorded. As shown in the figure, the BiOCl / Nd-AlPO4 material exhibits good radiation cooling performance.

[0061] Figure 5 This is the XPS full spectrum of the BiOCl / Nd-AlPO4 prepared in Example 1. The XPS full spectrum results show that all the constituent elements corresponding to the composite material are present in the sample, indicating that the composite structure has been successfully constructed. No obvious impurity peaks were found in the figure, indicating that the obtained sample has high purity.

Claims

1. A composite material of bismuth oxychloride and neodymium-doped aluminum phosphate, characterized by, The composite material is composed of bismuth oxychloride and neodymium-doped aluminum phosphate.

2. The composite material of bismuth oxychloride and neodymium-doped aluminum phosphate according to claim 1, characterized in that, The molar ratio of bismuth oxychloride to neodymium-doped aluminum phosphate is 1:1 to 3:1, and the molar ratio of aluminum to neodymium in neodymium-doped aluminum phosphate is 1:0.01 to 1:0.

03.

3. The method for preparing the composite material of bismuth oxychloride and neodymium-doped aluminum phosphate according to claim 1 or 2, characterized in that, The preparation method includes the following steps: S1. Neodymium nitrate or its hydrate is mixed with an aqueous solution of aluminum nitrate at a molar ratio of aluminum to neodymium of 1:0.01 to 1:0.03 to obtain solution A; S2. While continuously stirring, add the aqueous solution of ammonium dihydrogen phosphate to solution A, continue stirring and mixing until homogeneous, and adjust the pH of the solution to 6-8 to obtain solution B; S3. Transfer solution B to a high-pressure reactor and react at 120~150 ℃ for 6~12 h. After the reaction is complete, cool naturally to room temperature, collect the precipitate by centrifugation, wash and dry it, and then calcine it at 300~500 ℃ for 2~4 h to obtain neodymium-doped aluminum phosphate, denoted as powder C. S4. Mix powder C with bismuth nitrate solution until homogeneous. The molar ratio of bismuth nitrate to aluminum nitrate used to prepare neodymium-doped aluminum phosphate is 1:1 to 3:

1. Then adjust the pH of the solution to 6 to 8 to obtain solution D. S5. Transfer solution D to a high-pressure reactor, place the reactor in a microwave-assisted hydrothermal synthesis device, set the reaction temperature to 160~180℃, and the reaction time to 12~24 h. After the reaction is completed, allow the reactor to cool naturally to room temperature, centrifuge the reaction solution, collect the precipitate, and after washing and drying, obtain the composite material of bismuth oxychloride and neodymium-doped aluminum phosphate.

4. The preparation method according to claim 3, characterized in that, In step S1, 5-10 g of aluminum nitrate is weighed and dissolved in 50-100 mL of deionized water to obtain an aqueous solution of aluminum nitrate.

5. The preparation method according to claim 3, characterized in that, In step S1, stir the mixture on a magnetic stirrer at a speed of 200-500 r / min for 30-60 min.

6. The preparation method according to claim 3, characterized in that, In step S2, 3-7 g of ammonium dihydrogen phosphate is weighed and dissolved in 50-100 mL of deionized water to obtain an aqueous solution of ammonium dihydrogen phosphate.

7. The preparation method according to claim 3, characterized in that, In step S3, the washed precipitate is dried at 60-80℃ for 8-12 h.

8. The preparation method according to claim 3, characterized in that, In step S4, bismuth nitrate and 0.5-2 mol / L HCl are added to 70-100 mL of deionized water in a molar ratio of 1:1 to 3:1, and stirred for 1-2 h to form a bismuth nitrate solution.

9. The preparation method according to claim 3, characterized in that, In step S5, the washed precipitate is dried at 60~100℃ for 6~8 h.

10. The application of the composite material of bismuth oxychloride and neodymium-doped aluminum phosphate according to claim 1 or 2 in the preparation of photocatalysts.

11. The application of the bismuth oxychloride and neodymium-doped aluminum phosphate composite material according to claim 1 or 2 in the preparation of formulations with dual functions of photodegradation and radiation cooling.

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