Preparation method and application of inorganic-organic hybrid polyoxotungstate photo-thermal material with wide spectrum absorption
By preparing inorganic-organic hybrid polytungoxoate photothermal materials, the problems of high energy consumption and poor stability of organic free radical materials in seawater desalination technology have been solved, achieving efficient photothermal conversion and stable seawater desalination effect.
Patent Information
- Application Number
- CN202610178274.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-08
- Publication Date
- 2026-05-15
AI Technical Summary
Existing seawater desalination technologies suffer from high energy consumption, complex operation, and high maintenance costs. Furthermore, organic free radical materials exhibit poor stability under environmental conditions, making them difficult to widely apply to solar-driven interfacial photothermal evaporation technology.
An inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption was prepared by an electrochemical method. Combining the structural advantages of perylene molecules and decatungstate, the inorganic-organic hybrid polytungoxate photothermal material was generated through an electrochemical oxidation reaction, achieving high stability and broad-spectrum absorption.
It achieves high photothermal conversion efficiency, with an evaporation rate as high as 3.02 kg·m-2·h-1 and a solar-to-steam conversion efficiency of 96.40%. It exhibits good stability during long-term operation, and the freshwater quality meets the standards, thus solving the freshwater shortage problem.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of photothermal conversion materials technology, specifically relating to the preparation method and application of an inorganic-organic hybrid polytungoxoate photothermal material with broad-spectrum absorption. Background Technology
[0002] Global freshwater scarcity has become one of the key challenges restricting socio-economic development. Existing seawater desalination technologies, such as reverse osmosis, distillation, electrodialysis, and ion exchange, have alleviated the water shortage problem to some extent, but they suffer from drawbacks such as high energy consumption, complex operation, and high maintenance costs, making them difficult to widely apply in resource-limited areas.
[0003] Solar-driven interfacial photothermal evaporation technology has become a highly promising alternative for freshwater acquisition due to its low energy consumption, simple equipment, and low cost. The core of this technology is the efficient conversion of solar energy into thermal energy through photothermal materials, enabling rapid evaporation and purification of interfacial water. Organic free radical materials, due to their open-shell electronic structure resulting in a small band gap, possess broad-spectrum absorption potential; however, their poor stability under environmental conditions and susceptibility to deactivation or structural damage limit their applications.
[0004] Polyoxometalates are large-sized inorganic anion clusters formed by high-valence transition metal ions linked by oxygen bridges. They possess structural stability, high charge density, and the ability to stabilize various cations. Combining the controllable electrochemical radical generation process with the structural stability advantage of polyoxometalate anions holds promise for constructing organic-inorganic hybrid photothermal materials that combine broadband absorption, high photothermal efficiency, and excellent evaporation performance, providing new material design ideas for solar-driven interfacial photothermal evaporation systems. Summary of the Invention
[0005] To address the aforementioned problems, this invention proposes a method for preparing and applying an inorganic-organic hybrid polytungoxoate photothermal material with broad-spectrum absorption.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: An inorganic-organic hybrid polytungstenoxate photothermal material with broad spectral absorption, wherein the structural formula of the inorganic-organic hybrid polytungstenoxate photothermal material with broad spectral absorption is Per4W 10 O 32 Per is a perylene molecule; the inorganic-organic hybrid polytungstenoxate photothermal material with broad spectral absorption is a black bulk crystal that can generate continuous and wide-range light absorption in the visible to near-infrared region.
[0007] Preferably, the crystal structure of the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption belongs to the triclinic crystal system, with space group [missing information]. P -1, the unit cell parameters are: a= 12.0300(7) Å, b = 13.1669(8) Å, c =13.2814(8) Å, α = 60.645(2)°, β = 71.234(2)°, γ = 82.121(2)°.
[0008] A method for preparing an inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption includes the following steps: S1. Prepare perylene and decatungstate precursor tetrabutylammonium decatungstate; S2. Perylene and tetrabutylammonium decatungstate are dissolved in a mixed solvent of dichloromethane and acetonitrile to obtain a homogeneous reaction solution; the volume ratio of dichloromethane to acetonitrile is 1:1, and the molar ratio of perylene to tetrabutylammonium decatungstate is 1:(1-3). S3. Add the reaction solution to the H-type electrolytic cell, use inert metal electrodes as the anode and cathode, and carry out an electrochemical oxidation reaction under a constant current of 1 μA, so that the perylene molecule is oxidized at the anode interface and assembled with the decatungstate anion. S4. After the electrochemical reaction proceeds for 5-10 days, bulk crystals are obtained on the surface of the anode electrode. After separation, cleaning and drying, inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption is obtained.
[0009] Preferably, in step S2, the total volume of the mixed solvent is 20 mL.
[0010] Preferably, in step S2, the molar ratio of perylene to tetrabutylammonium decatungstate is 1:2.
[0011] Preferably, in step S3, the inert metal electrode is a platinum electrode.
[0012] Preferably, in step S3, the electrochemical oxidation reaction is carried out under room temperature and atmospheric pressure conditions.
[0013] Preferably, in step S4, the electrochemical reaction takes 7 days.
[0014] Application of a polytungstenoxate photothermal material with broad spectral absorption inorganic-organic hybrid, wherein the polytungstenoxate photothermal material with broad spectral absorption inorganic-organic hybrid is used as a photothermal functional material in the fields of solar-driven interfacial photothermal evaporation and water treatment.
[0015] Preferably, when the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption is applied to a two-dimensional solar interfacial evaporation system, the evaporation rate is 1.89 kg·m³.-2 ·h -1 The solar-to-steam conversion efficiency is 96.40%; when the inorganic-organic hybrid polytungstenoxate photothermal material with broad-spectrum absorption is applied to a three-dimensional interfacial evaporation system with a hydrogel structure, the evaporation rate is 3.02 kg·m³. -2 ·h -1 It can be used for seawater desalination.
[0016] By adopting the above technical solution, the present invention has the following beneficial effects: 1. The inorganic-organic hybrid polytungstenoxate photothermal material with broad-spectrum absorption prepared by this invention has an inorganic-organic hybrid structure, which combines the broad-spectrum absorption characteristics of organic perylene molecules with the high stability advantage of polytungstenoxates. It achieves continuous strong absorption in the ultraviolet to short-wave infrared region and has a photothermal conversion efficiency of up to 98.24%, thus solving the problem of poor stability of traditional organic photothermal materials.
[0017] 2. The preparation method of the present invention adopts a mild and controllable electrochemical oxidation process. By adjusting the reaction parameters (such as molar ratio, current, and time), the precise growth of crystals can be achieved. The preparation process is simple, highly reproducible, and the resulting material has a stable structure and high purity.
[0018] 3. When the inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption of the present invention is applied to a two-dimensional solar interfacial evaporation system, it can achieve a yield of 1.89 kg·m³. -2 ·h -1 The evaporation rate corresponds to a solar-to-steam conversion efficiency of 96.40%, which is close to the theoretical limit after deducting the contribution of dark evaporation. Introducing inorganic-organic hybrid polytungstic oxometalate photothermal materials with broad-spectrum absorption into a three-dimensional interfacial evaporation system with a hydrogel structure can increase the evaporation rate to 3.02 kg·m³. -2 ·h -1 This material can achieve stable and reliable seawater desalination under long-term operating conditions, and the quality of the desalinated water meets the relevant drinking water standards. The inorganic-organic hybrid polytungstenoxate photothermal material with broad-spectrum absorption has excellent application results in the field of solar-driven interfacial photothermal evaporation. Both the two-dimensional system and the three-dimensional hydrogel system exhibit high evaporation rate and high solar-steam conversion efficiency. Moreover, it can inhibit salt deposition during long-term seawater desalination operation and ensure that the desalinated water quality meets the standards. It provides an efficient and sustainable technical solution for solving the global freshwater shortage problem. Attached Figure Description
[0019] Figure 1 Per4W was prepared for this invention. 10 O 32 Schematic diagram of H-type electrolytic cell device and crystal growth morphology diagram; Figure 2Per4W prepared for this invention 10 O 32 A schematic diagram of the crystal structure; Figure 3 Per4W prepared for this invention 10 O 32 Powder X-ray diffraction patterns under different heating temperatures; Figure 4 Per4W prepared for this invention 10 O 32 Infrared spectra before and after thermochromic treatment; Figure 5 Per4W prepared for this invention 10 O 32 Absorption spectrum in the ultraviolet-visible-infrared region; Figure 6 The diagram shows the photothermal properties of the materials related to this invention. Figure 7 Per4W prepared for this invention 10 O 32 Electron paramagnetic resonance spectrum; Figure 8 Per4W prepared for this invention 10 O 32 Application diagram and performance comparison of solar-driven interfacial photothermal evaporation system. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to examples. It should be understood that the specific examples described herein are merely illustrative and not intended to limit the invention.
[0021] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.
[0022] See Figures 1 to 8 .
[0023] Example 1: Per4W 10 O 32 Preparation: S1. Preparation of precursors: Perylene (Per) is an analytical grade reagent and can be used directly; the decatungstate precursor is tetrabutylammonium decatungstate (TBA4W). 10 O 32 The preparation method can be found in the literature "Polyoxal Chemistry" (by Chen Weilin and Wang Enbo, Beijing: Science Press, p. 383).
[0024] S2. Preparation of reaction solution: Perylene (Per) and tetrabutylammonium decatungstate are dissolved in a mixed solvent of dichloromethane and acetonitrile to obtain a homogeneous reaction solution; wherein the volume ratio of dichloromethane to acetonitrile is 1:1, the total volume of the mixed solvent is 20 mL, and the molar ratio of perylene to tetrabutylammonium decatungstate is 1:2.
[0025] S3. Electrochemical reaction: The above reaction solution is added to an H-type electrolytic cell. Platinum electrodes are set on both sides of the electrolytic cell as anode and cathode, respectively. A constant current of 1 μA is applied at room temperature to carry out an electrochemical oxidation reaction, so that perylene molecules are oxidized at the anode interface and free radicals are generated in situ, which then undergo an assembly reaction with decatungstate anions.
[0026] S4. Crystal Growth and Collection: After 7 days of continuous electrochemical reaction, dark-colored bulk crystals grew on the surface of the anode electrode. After the reaction was completed, the electrode was removed, the obtained crystals were separated, and after cleaning and drying, Per4W, an inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption, was obtained. 10 O 32 ,like Figure 1 As shown.
[0027] Characterization and performance testing of crystals: (1) Determination of crystal structure Selected single crystals of suitable size, regular shape, and transparency were examined under a microscope. Diffraction data were collected using a Bruker APEX II CCD diffractometer with Mo-Kα rays (λ = 0.71073 Å) monochromated by a graphite monochromator. The crystal structure was analyzed and refined using the Shelextl-97 program via a direct method. Non-hydrogen atoms and their anisotropic treatment parameters were corrected using the full-matrix least squares method. All hydrogen atoms were obtained through theoretical hydrogenation. The resulting crystal structure diagram is shown below. Figure 2 As shown. Some crystallographic data and refinement parameters are shown in Table 1.
[0028] Table 1: Crystal parameters of the compounds
[0029] (2) Powder diffraction characterization: Take an appropriate amount of the single crystal prepared in Example 1 above, grind it thoroughly into powder, and measure the powder diffraction pattern of the conductive material at room temperature (e.g., Figure 3 As shown in the figure, a comparison with the diffraction peaks simulated based on single-crystal diffraction data shows that the experimental results agree well with the fitting results of the Mercury software, indicating that the compound is a pure phase. The anisotropy of the crystal leads to differences in the peak intensity of some diffraction peaks.
[0030] (3) Infrared spectral characterization: like Figure 4 As shown, compound Per4W 10 O 32 At 3101cm -1 3059 cm -1 The peak at 1637 cm⁻¹ is attributed to the characteristic absorption peak of the CH bond; -1 1558cm -1 1499cm -1 The peak at 1448 cm⁻¹ is attributed to the characteristic absorption of the benzene ring skeleton. -1 1333cm -1 The peak at 1350 cm⁻¹ is attributed to the characteristic absorption peak of CH in -CH₃; -1 -1100cm -1 The peaks within the range are mainly attributed to the characteristic absorption peaks of CN; 1000 cm⁻¹ -1 The following peaks are mainly attributed to the stretching vibrations of ν(WO) and ν(W=O) and the bending vibrations of part of δ(=CH).
[0031] (4) Ultraviolet-Visible-Infrared Absorption Characterization: like Figure 5 As shown, compound Per4W 10 O 32 It exhibits strong absorption in the 200-2500 nm range, demonstrating broad-spectral absorption characteristics.
[0032] (5) Photothermal performance test: The photothermal conversion efficiency of this material reaches 98.24%.
[0033] (6) Evaporation performance test: (1) Preparation of two-dimensional evaporator: The material was dispersed in a solvent, filtered and loaded onto the surface of filter paper, and dried to obtain a two-dimensional interfacial photothermal evaporator; under light irradiation, the evaporation rate was 1.89 kg·m -2 ·h -1 The solar-to-steam conversion efficiency is 96.40%.
[0034] (2) Preparation of the three-dimensional evaporator: 3.1 g of polyvinyl alcohol (PVA) was weighed and dissolved in 45 mL of deionized water, and heated and stirred until dissolved; 5 mL of PVA aqueous solution was taken, 120 μL of glutaraldehyde and 100 mg of the photothermal material were added, and after mixing evenly, 0.3 g of sodium bicarbonate and 2 mL of hydrochloric acid were added, and the mixture was stirred and reacted for 30 min to obtain a precursor gel; after pre-freezing, it was freeze-dried to obtain a three-dimensional porous interfacial photothermal evaporator; the evaporation rate under light irradiation was 3.02 kg·m -2 ·h -1 No significant salt deposition was observed during long-term seawater desalination operation, and the freshwater quality met drinking water standards.
[0035] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A polytungstenoxate photothermal material with inorganic-organic hybridization exhibiting broad-spectrum absorption, characterized in that: The structural formula of the inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption is Per4W. 10 O 32 Per is a perylene molecule; the inorganic-organic hybrid polytungstenoxate photothermal material with broad spectral absorption is a black bulk crystal that can generate continuous and wide-range light absorption in the visible to near-infrared region.
2. The inorganic-organic hybrid polytungoxoate photothermal material with broad-spectrum absorption as described in claim 1, characterized in that: The crystal structure of the inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption belongs to the triclinic crystal system, with space group [missing information]. P -1, the unit cell parameters are: a = 12.0300(7) Å, b = 13.1669(8) Å, c = 13.2814(8)Å, α = 60.645(2)°, β = 71.234(2)°, γ = 82.121(2)°.
3. A method for preparing an inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Prepare perylene and decatungstate precursor tetrabutylammonium decatungstate; S2. Perylene and tetrabutylammonium decatungstate are dissolved in a mixed solvent of dichloromethane and acetonitrile to obtain a homogeneous reaction solution; the volume ratio of dichloromethane to acetonitrile is 1:1, and the molar ratio of perylene to tetrabutylammonium decatungstate is 1:(1-3). S3. Add the reaction solution to the H-type electrolytic cell, use inert metal electrodes as the anode and cathode, and carry out an electrochemical oxidation reaction under a constant current of 1μA, so that the perylene molecule is oxidized at the anode interface and assembled with the decatungstate anion. S4. After the electrochemical reaction proceeds for 5-10 days, bulk crystals are obtained on the surface of the anode electrode. After separation, cleaning and drying, inorganic-organic hybrid polytungoxate photothermal material with broad-spectrum absorption is obtained.
4. The method for preparing the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 3, characterized in that: In step S2, the total volume of the mixed solvent is 20 mL.
5. The method for preparing the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 3, characterized in that: In step S2, the molar ratio of perylene to tetrabutylammonium decatungstate is 1:
2.
6. The method for preparing the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 3, characterized in that: In step S3, the inert metal electrode is a platinum electrode.
7. The method for preparing the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 3, characterized in that: In step S3, the electrochemical oxidation reaction is carried out at room temperature and atmospheric pressure.
8. The method for preparing the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 3, characterized in that: In step S4, the electrochemical reaction takes 7 days.
9. An application of a polytungstenoxate photothermal material with broad spectral absorption as described in any one of claims 1-2, characterized in that: The inorganic-organic hybrid polytungstenoxate photothermal material with broad spectral absorption is used as a photothermal functional material in the fields of solar-driven interfacial photothermal evaporation and water treatment.
10. The application of the inorganic-organic hybrid polytungoxoate photothermal material with broad spectral absorption as described in claim 9, characterized in that: When the inorganic-organic hybrid polytungoxoate photothermal material with broad-spectrum absorption is applied to a two-dimensional solar interfacial evaporation system, the evaporation rate is 1.89 kg·m³. -2 ·h -1 The solar-to-steam conversion efficiency is 96.40%; when the inorganic-organic hybrid polytungstenoxate photothermal material with broad-spectrum absorption is applied to a three-dimensional interfacial evaporation system with a hydrogel structure, the evaporation rate is 3.02 kg·m³. -2 ·h -1 It can be used for seawater desalination.