A high-entropy perovskite full-waveband solar energy absorbing material and a preparation method thereof

Abstract

The application relates to a high-entropy perovskite full-waveband solar energy absorption material, which has a molecular formula of AB03; A is La element; B is any five elements in Fe, Mn, Sc, Co, Ni, Al, Ti and Hf, and the metal atoms are in an equimolar ratio; the band gap of the absorption material is less than 1.5 eV, and the absorption material has full-waveband solar energy absorption characteristics in the whole waveband of 0.3-2.5 mu m. The high-entropy perovskite full-waveband solar energy absorption material not only retains the excellent high-temperature stability of a traditional perovskite, but also further increases the thermal stability of the material through an entropy-driven structure stability effect, and can be applied to the fields of a concentrated solar power generation system, a solar water heater, solar interface evaporation and the like.

Description

Technical Field

[0001] This invention relates to the field of solar energy absorbing materials, and more particularly to a high-entropy perovskite type full-band solar energy absorbing material and its preparation method. Background Technology

[0002] Solar energy, as a clean and renewable energy source, can provide the Earth with a large amount of energy every hour, demonstrating its enormous potential to replace fossil fuels. Solar thermal utilization technology is a crucial means of capturing and collecting solar radiation, with a wide range of applications, including hot water systems, seawater desalination, medical sterilization, photothermal catalysis, anti-icing, and solar thermal power generation. Particularly in the field of solar thermal power generation, concentrated solar power (CSP) systems are a promising solar power technology that has attracted considerable attention from researchers. Efficiently utilizing solar energy also offers possibilities for reducing carbon emissions and promoting the development of sustainable energy technologies. Solar thermal absorption materials are the core component of solar thermal technology. To improve photothermal conversion efficiency, it is necessary to increase the solar energy absorption rate of the materials. Furthermore, for concentrated solar power systems, which need to operate under high-temperature conditions for extended periods, the high-temperature thermal stability of the materials is also crucial.

[0003] Lanthanide perovskite composite oxides are particularly suitable for high-temperature applications due to their stable structure, high melting point, and excellent high-temperature oxidation resistance. The general formula for this material is ABO3, where A is La coordinated with 12 oxygen atoms, primarily used to stabilize the perovskite structure, and the B site is typically composed of transition metal elements (Cr, Mn, Fe, Co, Ni, Cu, Ti, etc.), coordinated with 6 oxygen atoms and located at the center of a BO6 hexahedron. LaCrO3, LaFeO3, and LaMnO3 have been proven to have good solar energy absorption characteristics. However, the relatively wide band gap of single lanthanide perovskites limits their absorption characteristics across the entire solar energy spectrum (ultraviolet, visible, and near-infrared regions).

[0004] High-entropy oxides are an extension of the high-entropy alloy concept to entropy-stabilized oxides, representing a novel type of ceramic material. The key to high-entropy design lies in using combinations of four or more equiatomic or near-equiatomic cations. High mixing entropy lowers the Gibbs free energy, and its simple structure stabilizes the disordered solid solution phase, overcoming the enthalpy-driven phase separation problem that occurs during single-component doping. Therefore, high-entropy oxide materials possess high entropy values ​​and low Gibbs free energy, along with significant lattice distortion, resulting in excellent performance in electrical, optical, magnetic, and catalytic applications. However, reports on high-entropy oxide materials as full-spectrum solar energy absorbers are relatively limited. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a high-performance high-entropy perovskite type full-band solar energy absorbing material.

[0006] Another technical problem to be solved by the present invention is to provide a method for preparing the high-entropy perovskite type full-band solar energy absorbing material.

[0007] To address the aforementioned problems, the present invention provides a high-entropy perovskite-type full-band solar energy absorbing material, characterized in that: the molecular formula of the absorbing material is ABO3; wherein: A is La; B is any five elements selected from Fe, Mn, Sc, Co, Ni, Al, Ti, and Hf, and the metal atoms are in equimolar ratio; the band gap of the absorbing material is less than 1.5 eV, and it exhibits full-band solar energy absorption characteristics across the entire wavelength range of 0.3 to 2.5 μm.

[0008] The preparation method of the high-entropy perovskite full-band solar energy absorbing material described above is characterized in that: the method refers to using any five powders selected from Fe2O3, MnO2, Sc2O3, Co2O3, Ni2O3, Al2O3, Ti2O3, and Hf2O5, and La2O3 as raw materials, and mixing them by ball milling according to a metal atomic molar ratio of 1:1:1:1:1:5. After drying and grinding, the mixture powder is obtained. The mixture powder is then calcined at high temperature in a muffle furnace, and after cooling and grinding, a full-band solar energy absorbing material with a perovskite structure is obtained.

[0009] The conditions for ball milling and mixing refer to wet ball milling using a planetary ball mill, with a milling speed of 300~500 r / min, a milling time of 10~20 hours, and a mass ratio of ball material to anhydrous ethanol of 2~5:1:3.

[0010] The conditions for high-temperature calcination are a calcination temperature of 1000~1200℃, a heating rate of 3~5℃ / min, and a calcination time of 4~8 hours.

[0011] The cooling method is one of furnace cooling, air quenching cooling, and liquid nitrogen quenching cooling.

[0012] Compared with the prior art, the present invention has the following advantages: 1. This invention introduces impure energy levels through multi-principal doping at the B site, thereby reducing the band gap of the material. The resulting absorbing material has a band gap of less than 1.5 eV, which is beneficial for electronic transitions, thus exhibiting excellent photothermal performance. Simultaneously, during the synthesis process, cations exhibit different valence states, generating oxygen vacancies and forming intermediate energy levels, further enhancing the absorption capacity of solar energy.

[0013] 2. The high-entropy perovskite material described in this invention features a single phase, high purity, small particle size, and uniform elemental distribution. It also exhibits full-band solar energy absorption characteristics, with a maximum solar energy absorption rate of 0.875 across the entire 0.3–2.5 μm band. Furthermore, this high-entropy perovskite full-band solar energy absorbing material not only retains the excellent high-temperature stability of traditional perovskites, but also benefits from entropy-driven structural stability effects that further enhance its thermal stability. After a 24-hour thermal stability test at 1500℃, the data fluctuation range was within 0.02. Therefore, it can be applied in concentrated solar power generation systems, solar water heaters, and solar interface evaporation, among other fields.

[0014] 3. The preparation process of this invention is simple to operate, has high production efficiency, requires no complicated post-processing, and can be used for industrial production. Attached Figure Description

[0015] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] Figure 1 Example 1 of the present invention: La(Fe) 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 XRD pattern of O3.

[0017] Figure 2 Example 1 of the present invention: La(Fe) 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 Solar absorption spectrum of O3 in the 0.3~2.5μm band.

[0018] Figure 3 The La(Fe) described in Embodiment 1 of the present invention 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 XRD patterns of O3 before and after thermal stability experiment.

[0019] Figure 4 Example 2 of the present invention: La(Fe) 0.2 Mn 0.2 Ti 0.2 Co 0.2 Ni 0.2 XRD pattern of O3.

[0020] Figure 5 Example 3 of the present invention: La(Fe) 0.2 Mn 0.2 Sc0.2 Co 0.2 Ni 0.2 XRD pattern of O3.

[0021] Figure 6 Example 4 of the present invention: La(Fe) 0.2 Mn 0.2 Hf 0.2 Co 0.2 Ni 0.2 XRD pattern of O3. Detailed Implementation

[0022] A high-entropy perovskite-type full-band solar energy absorbing material is disclosed. The molecular formula of this material is ABO3, where A represents La, and B represents any five elements selected from Fe, Mn, Sc, Co, Ni, Al, Ti, and Hf, with equimolar ratios of the metal atoms. The absorbing material has a band gap of less than 1.5 eV and exhibits full-band solar energy absorption characteristics across the entire wavelength range of 0.3–2.5 μm.

[0023] The preparation method is as follows: Using any five powders selected from Fe2O3, MnO2, Sc2O3, Co2O3, Ni2O3, Al2O3, Ti2O3, and Hf2O5, along with La2O3, as raw materials, wet ball milling is performed using a planetary ball mill at a metal atomic molar ratio of 1:1:1:1:1:5. The ball milling speed is 300-500 r / min, the milling time is 10-20 hours, and the mass ratio (g / g) of anhydrous ethanol to the ball material is 2-5:1:3. After ball milling, the mixture is dried at 80℃ for 10 hours, then ground again to obtain the mixed powder. The mixed powder is then calcined at high temperature in a muffle furnace at 1000-1200℃, with a heating rate of 3-5℃ / min, for 4-8 hours. After calcination, the material is cooled to room temperature using one of the following methods: furnace cooling, air quenching, or liquid nitrogen quenching. Finally, it is ground to obtain a full-band solar energy absorbing material with a perovskite structure.

[0024] Example 1: A method for preparing a high-entropy perovskite type full-band solar energy absorbing material: 5 mol of La₂O₃, 1 mol of Fe₂O₃, 1 mol of MnO₂, 1 mol of Al₂O₃, 1 mol of Co₂O₃, and 1 mol of Ni₂O₃ were weighed as raw materials. Zirconia balls, raw materials, and anhydrous ethanol were added to a planetary ball mill at a mass ratio (g / g) of 5:1:3. The milling was performed for 1 hour at 500 r / min, followed by a 10-min pause. This constituted one milling cycle. After a 10-min pause, milling was repeated for another hour at 500 r / min, for a total of 20 hours. The milled mixture was dried at 80℃ for 10 hours, then ground to obtain a powder mixture. This powder mixture was then calcined in a muffle furnace at 1200℃ with a heating rate of 5℃ / min for 4 hours. After calcination, the mixture was quenched in liquid nitrogen and cooled to room temperature. Finally, it was ground to obtain single-phase La(Fe₂O₃)₃. 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 O3 absorbing material.

[0025] Figure 1 La(Fe) as described in Example 1 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 The XRD pattern of the O3 absorbing material shows that the spectrum is in excellent agreement with the LaCoO3 spectrum (PDF#48-0123) with a perovskite structure in the ICDD database, indicating that the absorbing material prepared in this embodiment has a perovskite structure.

[0026] The obtained La(Fe) 0.2 Mn 0.2 Al 0.2 Co 0.2 Ni 0.2 Evaluation of the absorption characteristics and thermal stability of O3 absorbing materials: Test method: The ultra-wideband absorption characteristics of the absorbing material were evaluated using a Lambda 950 ultra-wideband / visible / near-infrared spectrophotometer (equipped with a 150mm integrating sphere) manufactured by PerkinElmer, USA. The reflectance spectrum in the 0.3~2.5μm band was measured, and the solar absorptivity in this band was calculated according to the following formula.

[0027] Where: α(θ, λ) is the absorptivity of the material at the solar incidence angle θ and wavelength λ; R(θ,λ) is the reflectivity of the material at the solar incidence angle θ and wavelength λ; I S (λ) is the spectral radiation intensity of the sun when the atmospheric mass is AM 1.5.

[0028] The amount of test sample used was 0.2g.

[0029] The absorbent material was placed in an air atmosphere in a box furnace and subjected to a 24-hour thermal stability test at 1500°C.

[0030] The results showed that the solar energy absorption rate of this absorbing material was 0.875 in the 0.3~2.5μm wavelength range. Figure 2 As shown, this indicates that it has a high solar energy absorption rate in this wavelength band.

[0031] After thermal stability testing, the absorber material was found to have a solar absorptivity of 0.860 in the 0.3–2.5 μm wavelength range. Figure 3 As shown, the material did not undergo a phase transition after a 24-hour thermal stability test at 1500℃, indicating that the absorber has good thermal stability.

[0032] Example 2: A method for preparing a high-entropy perovskite type full-band solar energy absorbing material: 5 mol of La₂O₃, 1 mol of Fe₂O₃, 1 mol of MnO₂, 1 mol of Ti₂O₃, 1 mol of Co₂O₃, and 1 mol of Ni₂O₃ were weighed as raw materials. Zirconia balls, raw materials, and anhydrous ethanol were added to a planetary ball mill at a mass ratio (g / g) of 4:1:3. The milling was performed for 1 hour at 300 r / min, followed by a 10-min pause, constituting one milling cycle. This was repeated for another hour at 300 r / min, for a total of 20 hours. After milling, the mixture was dried at 80℃ for 10 hours, then ground to obtain a powder mixture. This powder mixture was then calcined in a muffle furnace at 1000℃ with a heating rate of 3℃ / min for 5 hours. After calcination, it was air-quenched to room temperature and finally ground to obtain single-phase La(Fe₂O₃)₃. 0.2 Mn 0.2 Ti 0.2 Co 0.2 Ni 0.2 O3 absorbing material.

[0033] Figure 4 La(Fe) as described in Example 2 0.2 Mn 0.2 Ti 0.2 Co 0.2 Ni 0.2 The XRD pattern of the O3 absorbing material shows that the spectrum is in excellent agreement with the LaCoO3 spectrum (PDF#48-0123) with a perovskite structure in the ICDD database, indicating that the absorbing material prepared in this embodiment has a perovskite structure.

[0034] The obtained La(Fe) 0.2 Mn 0.2 Ti 0.2 Co 0.2 Ni 0.2 Evaluation of the absorption characteristics and thermal stability of O3 absorbing materials: The testing method and the amount of test sample used are the same as in Example 1.

[0035] The results showed that the solar energy absorptivity of the absorber material in the 0.3~2.5μm band was 0.850; after thermal stability testing, the solar energy absorptivity of the absorber material in the 0.3~2.5μm band was measured to be 0.842.

[0036] Example 3: A method for preparing a high-entropy perovskite type full-band solar energy absorbing material: 5 mol of La₂O₃, 1 mol of Fe₂O₃, 1 mol of MnO₂, 1 mol of Sc₂O₃, 1 mol of Co₂O₃, and 1 mol of Ni₂O₃ were weighed as raw materials. Zirconia balls, raw materials, and anhydrous ethanol were added to a planetary ball mill at a mass ratio (g / g) of 4:1:3. The milling was performed for 1 hour at 400 r / min, followed by a 10-min pause, constituting one milling cycle. This was repeated for another hour at 400 r / min, for a total of 10 hours of milling. After milling, the mixture was dried at 80℃ for 10 hours, then ground to obtain a powder mixture. This powder mixture was then calcined in a muffle furnace at 1000℃ with a heating rate of 3℃ / min for 8 hours. After calcination, the mixture was cooled to room temperature in the furnace and finally ground to obtain single-phase La(Fe₂O₃)₃. 0.2 Mn 0.2 Sc 0.2 Co 0.2 Ni 0.2 O3 absorbing material.

[0037] Figure 5 La(Fe) as described in Example 3 0.2 Mn 0.2 Sc 0.2 Co 0.2 Ni 0.2 The XRD pattern of the O3 absorbing material is basically consistent with the LaCoO3 spectrum (PDF#48-0123) with perovskite structure in the ICDD database, indicating that the absorbing material prepared in this embodiment is a single-phase solid solution with perovskite structure.

[0038] The obtained La(Fe) 0.2 Mn 0.2 Sc0.2 Co 0.2 Ni 0.2 Evaluation of the absorption characteristics and thermal stability of O3 absorbing materials: The testing method and the amount of test sample used are the same as in Example 1.

[0039] The results showed that the solar energy absorptivity of the absorber material in the 0.3~2.5μm band was 0.845; after thermal stability testing, the solar energy absorptivity of the absorber material in the 0.3~2.5μm band was measured to be 0.838.

[0040] Example 4: A method for preparing a high-entropy perovskite type full-band solar energy absorbing material: 5 mol of La₂O₃, 1 mol of Fe₂O₃, 1 mol of MnO₂, 1 mol of Hf₂O₅, 1 mol of Co₂O₃, and 1 mol of Ni₂O₃ were weighed as raw materials. Zirconia balls, raw materials, and anhydrous ethanol were added to a planetary ball mill at a mass ratio (g / g) of 2:1:3. The milling was performed for 1 hour at 300 r / min, followed by a 10-min pause, constituting one milling cycle. This was repeated for another hour at 300 r / min, for a total of 20 hours. After milling, the mixture was dried at 80℃ for 10 hours, then ground to obtain a powder mixture. This powder mixture was then calcined in a muffle furnace at 1000℃ with a heating rate of 3℃ / min for 8 hours. After calcination, the mixture was air-quenched to room temperature and finally ground to obtain single-phase La(Fe₂O₃)₅. 0.2 Mn 0.2 Hf 0.2 Co 0.2 Ni 0.2 O3 absorbing material.

[0041] Figure 6 La(Fe) as described in Example 4 0.2 Mn 0.2 Hf 0.2 Co 0.2 Ni 0.2 The XRD pattern of the O3 absorbing material is basically consistent with the LaCoO3 spectrum (PDF#48-0123) with perovskite structure in the ICDD database, indicating that the absorbing material prepared in this embodiment is a single-phase solid solution with perovskite structure.

[0042] The obtained La(Fe) 0.2 Mn 0.2 Hf 0.2 Co 0.2 Ni 0.2 Evaluation of the absorption characteristics and thermal stability of O3 absorbing materials: The testing method and the amount of test sample used are the same as in Example 1.

[0043] The results showed that the solar energy absorptivity of the absorber material in the 0.3~2.5μm wavelength range was 0.849; after thermal stability testing, the solar energy absorptivity of the absorber material in the 0.3~2.5μm wavelength range was measured to be 0.832.

[0044] The above description only illustrates the preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. The present invention is not limited to the above embodiments, and variations in its specific structure are permitted. All modifications made within the scope of the independent claims of this invention are also within the scope of protection of this invention.

Claims

1. A method for preparing a high-entropy perovskite-type full-band solar energy absorbing material, characterized in that: This method involves using any five powders selected from Fe2O3, MnO2, Sc2O3, Co2O3, Ni2O3, Ti2O3, and Hf2O5 (including Fe2O3, MnO2, Co2O3, and Ni2O3) and La2O3 as raw materials, and ball milling them together in a metal atomic molar ratio of 1:1:1:1:1:

5. After drying and grinding, a mixed powder is obtained. The mixed powder is then calcined at high temperature in a muffle furnace, cooled, and ground to obtain a full-band solar energy absorbing material with a perovskite structure. The molecular formula of this absorbing material is ABO3, where A is La, and B is any five elements selected from Fe, Mn, Sc, Co, Ni, Ti, and Hf (including Fe, Mn, Co, and Ni) in an equimolar ratio. The high-temperature calcination conditions are a calcination temperature of 1000~1200℃, a heating rate of 3~5℃ / min, and a calcination time of 4~8 hours.

2. The preparation method of a high-entropy perovskite full-band solar energy absorbing material as described in claim 1, characterized in that: The conditions for ball milling and mixing refer to wet ball milling using a planetary ball mill, with a milling speed of 300~500 r / min, a milling time of 10~20 hours, and a mass ratio of ball material to anhydrous ethanol of 2~5:1:

3.

3. The method for preparing a high-entropy perovskite full-band solar energy absorbing material as described in claim 1, characterized in that: The cooling method is one of furnace cooling, air quenching cooling, and liquid nitrogen quenching cooling.

4. The absorbent material prepared by the method according to claim 1, characterized in that: The absorber material has a band gap of less than 1.5 eV and exhibits full-band solar energy absorption characteristics across the entire wavelength range of 0.3 to 2.5 μm.

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