Naphthyl-linked metal ruthenium (ii) metal-organic frameworks, evaporators and methods of making and using the same

Abstract

The application discloses a naphthyl-bridged metal ruthenium (II) metal organic framework material, an evaporator and a preparation method and application thereof. A ruthenium (II) is used as a metal center, and an organic ligand with two end coordination groups shown in a structure of formula I is selected to react, the two end coordination groups are respectively coordinated with a ruthenium complex precursor, linear coordination extension is realized by using the coordination characteristics of ruthenium, and a homogeneous linear polymer formed by naphthyl bridging is prepared; the metal ruthenium (II) complex has the MOFs material structure, the excellent optical performance of the metal ruthenium (II) complex is combined with the structural advantages of the supramolecular MOFs material, and the application as a light-heat conversion material is realized; the water evaporation amount of the evaporator loaded with the naphthyl-bridged metal ruthenium (II) metal organic framework material is 0.76 kg·m ‑2 , and the evaporation efficiency reaches 1.50 kg·m ‑2 ·h ‑1 . The reaction synthesis route is simple, the yield is high, the preparation method is efficient and economical.

Description

Technical Field

[0001] This invention belongs to the field of functional materials technology of metal-organic complexes, specifically relating to a naphthyl-linked ruthenium(II) metal-organic framework material, an evaporator, its preparation method, and its application. Background Technology

[0002] The performance of metal-organic frameworks (MOFs) is closely related to their structure, and their functions can be effectively regulated through precise modification of organic ligands. Researchers have successfully constructed a series of high-performance MOFs by expanding the π-conjugated system, introducing functional groups, or optimizing ligand geometry. For example, expanding the π-conjugated system helps enhance the light absorption and charge transport efficiency of the material, while introducing specific functional groups can endow the material with unique catalytic or sensing properties. Nevertheless, current photothermal conversion materials still face challenges in practical applications. On the one hand, traditional materials have limited absorption capacity for visible and near-infrared light, resulting in insufficient photothermal conversion efficiency; on the other hand, the structural stability of these materials is poor, making it difficult to maintain long-term performance under high temperatures or complex environments. These factors limit the widespread application of photothermal materials in seawater desalination, wastewater treatment, and catalysis. Therefore, there is an urgent need to develop MOFs materials that combine high photothermal conversion efficiency with excellent structural stability. Summary of the Invention

[0003] For the reasons mentioned above, the first objective of this invention is to provide a naphthyl-linked ruthenium(II) metal-organic framework material, wherein the ruthenium(II) metal center is coordinated with the organic ligand to form a homogeneous linear polymer structure; the highly π-conjugated naphthyl structure gives the polymer a larger conjugated system, which not only enhances the optical properties of the ruthenium(II) complex, but also has the structural advantages of supramolecular MOF materials.

[0004] The second objective of this invention is to provide a method for preparing a naphthyl-linked ruthenium(II) metal-organic framework material, using a ruthenium(II) complex with 1,10-phenanthroline as a metal precursor, which reacts directly with an organic ligand to prepare a homogeneous linear polymer material; this provides a simple synthetic preparation method.

[0005] The third objective of this invention is to provide an application of a naphthyl-linked ruthenium(II) metal-organic framework material as a photothermal conversion material; the homogeneous linear ruthenium(II) polymer of this application has excellent photothermal conversion performance and has potential applications in photothermal conversion water evaporation for seawater desalination and water purification.

[0006] The fourth objective of this invention is to provide an evaporator with excellent water evaporation performance.

[0007] The first objective of this invention can be achieved by adopting the following technical solution:

[0008] A naphthyl-linked ruthenium(II) metal-organic framework material, wherein two nitrogen atoms on the same phenanthroline in the organic ligand of Formula I are coordinated with the same ruthenium atom, and one phenanthroline in each of two adjacent organic ligands of Formula I is coordinated with a ruthenium atom.

[0009]

[0010] The second objective of this invention can be achieved by adopting the following technical solution:

[0011] A method for preparing a naphthyl-linked ruthenium(II) metal-organic framework material.

[0012] The organic ligand with the structure shown in Formula I reacts with Ru(phen)Cl4 in an organic solvent under an inert gas atmosphere to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0013] Furthermore, the molar ratio of the organic ligand with the structure shown in Formula I to Ru(phen)Cl4 is 1:(1-1.2).

[0014] Furthermore, the organic solvent is one or a mixture of N,N-dimethylformamide and N,N-dimethylacetamide.

[0015] Furthermore, the molar-volume ratio of the organic ligand with the structure shown in Formula I to the organic solvent is 1 mmol: (5-50) mL.

[0016] Furthermore, the inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are 120-150℃ for 3-24 hours.

[0017] Furthermore, the reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and anhydrous ethanol respectively, and then vacuum dried at 35-50°C.

[0018] Furthermore, the organic ligand with the structure shown in Formula I is prepared by reacting 1,10-phenanthroline-5,6-dione and naphthalene-2,6-dicarboxaldehyde in the presence of an ammonium salt.

[0019] The third objective of this invention can be achieved by adopting the following technical solution:

[0020] The application of the naphthyl-linked ruthenium(II) metal-organic framework material as a photothermal conversion material.

[0021] Furthermore, the naphthyl-linked ruthenium(II) metal-organic framework material is used as a photothermal conversion material for seawater desalination and wastewater purification.

[0022] The fourth objective of this invention can be achieved by adopting the following technical solution:

[0023] An evaporator, the evaporator being a Janus evaporator, the evaporator comprising the aforementioned naphthyl-linked ruthenium(II) metal-organic framework material.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The naphthyl-linked ruthenium(II) metal-organic framework material of the present invention uses ruthenium(II) as the metal center to form a new coordination metal center with an organic ligand, and forms a homogeneous linear polymer through naphthyl bridging; it has the structure of MOFs material, and combines the excellent optical properties of ruthenium(II) complex with the structural advantages of supramolecular MOFs material, realizing its application as a photothermal conversion material.

[0026] 2. The method for preparing naphthyl-linked ruthenium(II) metal-organic framework materials of the present invention involves selecting a phenanthroline group coordinated with ruthenium(II) as a complex precursor and reacting it with an organic ligand having two terminal coordinating groups. The two terminal coordinating groups are respectively coordinated with the ruthenium complex precursor. By utilizing the coordination characteristics of ruthenium, linear coordination extension is achieved, and a homogeneous linear polymer is prepared. The reaction synthesis route is simple, the yield is high, and the preparation method is efficient and economical.

[0027] 3. Application of the naphthyl-linked ruthenium(II) metal-organic framework material of the present invention: The naphthyl-linked ruthenium(II) metal-organic framework material of the present invention has high efficiency of photothermal conversion and excellent structural stability, and therefore can be used as an excellent photothermal conversion material.

[0028] 4. An evaporator of the present invention is a Janus evaporator, loaded with the naphthyl-linked ruthenium(II) metal-organic framework material of this application, exhibiting higher water evaporation capacity and evaporation rate; the water evaporation capacity is 0.76 kg·m³. -2 The evaporation efficiency reaches 1.50 kg·m³. -2 ·h -1 Compared to pure MFS, the evaporation performance is improved by 200%. Attached Figure Description

[0029] Figure 1 The MALDI-TOF-MS spectrum of the ligand bipn prepared in Example 1;

[0030] Figure 2The ESI-MS spectrum of Ru-phen-bipn-2 prepared in Comparative Example 1 is shown below.

[0031] Figure 3 MALDI-TOF-MS spectra of Ru-phen-bipn-2 prepared for Comparative Example 1 in the range of 200-2000 m / z;

[0032] Figure 4 The MALDI-TOF-MS spectrum of Ru-phen-bipn-n prepared in Example 2 in the range of 200-2000 m / z;

[0033] Figure 5 The MALDI-TOF-MS spectrum of Ru-phen-bipn-n prepared in Example 2 in the range of 2k-10k m / z;

[0034] Figure 6 The image shows the XPS analysis of Ru-phen-bipn-n prepared in Example 2, where a is the total XPS spectrum, b is the C1s narrow spectrum, and c is the N1s narrow spectrum.

[0035] Figure 7 The XRD pattern of Ru-phen-bipn-n prepared in Example 2;

[0036] Figure 8 The images show the microstructure of Ru-phen-bipn-n prepared in Example 2; the left image is a SEM image, and the right image is a TEM image.

[0037] Figure 9 EDS elemental distribution diagram of Ru-phen-bipn-n prepared in Example 2;

[0038] Figure 10 The TG curve for thermal stability analysis of Ru-phen-bipn-n prepared in Example 2;

[0039] Figure 11 The UV absorption spectra of Ru-phen-bipn-2 prepared in Comparative Example 1 in different solvents (a) and the UV absorption spectra of Ru-phen-bipn-n prepared in Example 2 in different solvents (b);

[0040] Figure 12 The solid-state UV-Vis-NIR spectrum of Ru-phen-bipn-n prepared in Example 2;

[0041] Figure 13 The photothermal performance of Ru-phen-bipn-n prepared in Example 2 at different power densities is shown in the figure.

[0042] Figure 14 The Ru-phen-bipn-n prepared in Example 2 was at 1 W / cm 2 The following is a diagram of the photothermal cycle test;

[0043] Figure 15 Real-time photothermal test image of Ru-phen-bipn-n prepared for Example 2 (808nm, 1W / cm²) 2 );

[0044] Figure 16 The water contact angle of the photothermal layer of the Janus evaporator prepared in Example 7;

[0045] Figure 17 Temperature change curve of the Janus evaporator prepared in Example 7 under 808nm laser irradiation;

[0046] Figure 18 The graph shows the change in water evaporation amount with irradiation time when the Janus evaporator prepared in Example 7 is shown in (a); the graph shows the change in evaporation rate with irradiation time is shown in (b).

[0047] Figure 19 The graph shows the change in water evaporation amount with irradiation time when the Janus evaporator prepared in Example 7 is used at different salt concentrations (a); the graph shows the change in evaporation rate with irradiation time (b).

[0048] Figure 20 The Janus evaporator prepared for Example 7 is used at different salt concentrations. The evaporator desalination rate is plotted as follows (a); the evaporator desalination rate and evaporation rate are plotted as follows (b).

[0049] Figure 21 The diagram shows the water purification performance of the Janus evaporator prepared in Example 7; where a is a comparison of ion concentrations of seawater before and after desalination; b is the UV absorption spectrum of Congo red before and after purification; c is the UV absorption spectrum of methyl orange before and after purification; and d is the UV absorption spectrum of methylene blue before and after purification. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described in conjunction with specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] Ruthenium(II) complexes possess excellent optical properties, but they are mostly used in solution; even when prepared as mononuclear or polynuclear complexes, solid powders still struggle to expand their applications. MOFs, structurally framework materials, still exhibit a metal-ligand structure similar to ruthenium(II) complexes, thus forming ruthenium(II) MOF materials. Combining this with the structural advantages of supramolecular MOFs, the application of ruthenium(II) complexes in solid-state applications can be expanded.

[0052] Therefore, this invention provides a naphthyl-linked ruthenium(II) metal-organic framework material, an evaporator, its preparation method, and its application.

[0053] A naphthyl-linked ruthenium(II) metal-organic framework material, wherein two nitrogen atoms on the same phenanthroline in the organic ligand of Formula I are coordinated with the same ruthenium atom, and one phenanthroline in each of two adjacent organic ligands of Formula I is coordinated with a ruthenium atom.

[0054]

[0055] Ruthenium(II) is a central ligand capable of six-coordinate linkage. In this application, an organic ligand with the structure shown in Formula I is used to coordinate with ruthenium(II), wherein two pyridine nitrogen atoms on the same phenanthroline are coordinated with the same ruthenium atom; the two phenanthroline atoms of a ligand with the structure shown in Formula I are respectively coordinated with two different ruthenium(II) atoms; each ruthenium(II) atom is also coordinated with one phenanthroline atom on another organic ligand with the structure shown in Formula I; thus, by coordinating ruthenium(II) with phenanthroline atoms of different ligands with the structure shown in Formula I, the ligands with the structure shown in Formula I are linearly linked by controlling the coordination of two different ligands with the same ruthenium(II).

[0056] In one implementation, each ruthenium(II) metal is also coordinated with two pyridine nitrogen atoms on a phenanthroline ligand. Thus, each ruthenium(II) metal forms a six-coordinate structure; the ruthenium(II) metals form new metal coordination centers, which are linked by naphthyl groups to form naphthyl-linked ruthenium(II) metal-organic framework materials.

[0057] As one embodiment, the naphthyl-linked ruthenium(II) metal-organic framework material has the structure shown in Formula II:

[0058]

[0059] The units in parentheses are repeated units.

[0060] In this application, a homogeneous polymer material is formed by using ruthenium(II) as the metal center and bridging new metal centers infinitely with organic ligands. In terms of performance, while retaining the excellent optical properties of ruthenium(II) complexes, the functionality is further expanded by combining the structural advantages of supramolecular MOFs materials.

[0061] This application also provides a method for preparing a naphthyl-linked ruthenium(II) metal-organic framework material, wherein the organic ligand with the structure shown in Formula I reacts with Ru(phen)Cl4 in an organic solvent under an inert gas atmosphere to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0062] The ruthenium(II) of this application reacts with a Ru(phen)Cl4 precursor containing one phenanthroline ligand. The remaining four coordinates can coordinate with the phenanthroline groups of two different ligands of Formula I, extending the coordination in a linear direction; thereby linearly linking the different ligands of Formula I to form a naphthyl-linked ruthenium(II) metal-organic framework material. In Ru(phen)Cl4, phen is a 1,10-phenanthroline coordinating group.

[0063] In one embodiment, Ru(phen)Cl4 can be purchased or synthesized. In synthesis, RuCl3·H2O is reacted with 1,10-phenanthroline in an aqueous hydrochloric acid solution under an argon atmosphere and in the dark, stirred overnight, and then post-processed to obtain Ru(phen)Cl4.

[0064] As one embodiment, the organic ligand with the structure shown in Formula I is prepared by reacting 1,10-phenanthroline-5,6-dione and naphthalene-2,6-dicarboxaldehyde in the presence of an ammonium salt.

[0065] The organic ligand with the structure shown in Formula I was prepared by reacting 1,10-phenanthroline-5,6-dione with naphthalene-2,6-dicarboxaldehyde and ammonium acetate in acetic acid solution under reflux and followed by post-treatment.

[0066] As one embodiment, the molar ratio of the organic ligand with the structure shown in Formula I to Ru(phen)Cl4 is 1:(1-1.2).

[0067] In one embodiment, the organic solvent is one or a mixture of N,N-dimethylformamide, N,N-dimethylacetamide, or both.

[0068] As one embodiment, the molar-volume ratio of the organic ligand with the structure shown in Formula I to the organic solvent is 1 mmol: (5-50) mL.

[0069] In one embodiment, the inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are 120-150℃ for 3-24 hours.

[0070] As one implementation method, the reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and anhydrous ethanol respectively, and then vacuum dried at 35-50°C.

[0071] This application also provides the application of the naphthyl-linked ruthenium(II) metal-organic framework material as a photothermal conversion material.

[0072] As one embodiment, the naphthyl-linked ruthenium(II) metal-organic framework material is used as a photothermal conversion material for seawater desalination and wastewater purification.

[0073] This application also provides an evaporator, which is a Janus evaporator, comprising the aforementioned naphthyl-linked ruthenium(II) metal-organic framework material.

[0074] As one embodiment, the evaporator is a Janus evaporator with melamine sponge-loaded photothermal material.

[0075] As one embodiment, the photothermal material comprises a composition of PDMS precursor, phenylene-linked ruthenium(II) homogeneous linear polymer material, and ethyl acetate.

[0076] As one embodiment, PDMS precursor, curing agent and ethyl acetate are thoroughly mixed; naphthyl-linked ruthenium(II) metal-organic framework material is added and mixed further; melamine sponge is immersed in the resulting mixture, completely absorbed, and vacuum dried to obtain a Janus evaporator loaded with photothermal material.

[0077] The following specific examples will provide further details.

[0078] Example 1: Synthesis of ligand bipn

[0079] 0.42 g of 1,10-phenanthroline-5,6-dione, 0.19 g of naphthalene-2,6-dicarboxaldehyde, and 1.54 g of ammonium acetate were added to a flask containing 55 mL of acetic acid and reacted at 117 °C for 5 h. After cooling to room temperature, the supernatant was removed by centrifugation, and the resulting precipitate was washed with deionized water and anhydrous ethanol until the pH of the filtrate was weakly acidic or neutral. Then, the precipitate was reacted in ethanol at 75 °C for 2 h. After cooling to room temperature, it was filtered and washed with deionized water and anhydrous ethanol. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the organic ligand with the structure shown in Formula I, 1,3-bis(1H-imidazolium[4,5-f][1,10]phenanthroline-2-yl)benzene; named bipin; yield: 0.50 g, efficiency: 80%; its MALDI-TOF analysis results are as follows. Figure 1 As shown, the mass-to-charge ratio of the main peak is 566.82.

[0080] Example 2: Synthesis of the linear polymer Ru-phen-bipn-n

[0081] 1 mmol of bipn prepared in Example 1 and 1 mmol of Ru(phen)Cl4 were added to a flask containing 20 mL of N,N-dimethylformamide (DMF). The mixture was reacted at 150 °C for 6 h under a nitrogen atmosphere. After cooling to room temperature, the mixture was diluted with deionized water, filtered, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and anhydrous ethanol, respectively. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material, named Ru-phen-bipn-n; yield: 0.69 g, 70%.

[0082] Example 3

[0083] 1 mmol of bipn prepared in Example 1 and 1.2 mmol of Ru(phen)Cl4 were added to a flask containing 5 mL of N,N-dimethylformamide (DMF) and reacted at 120 °C for 18 h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was diluted with deionized water, filtered, and washed with dimethyl sulfoxide (DMSO), water, and anhydrous ethanol, respectively. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0084] Example 4

[0085] 1 mmol of bipn prepared in Example 1 and 1.05 mmol of Ru(phen)Cl4 were added to a flask containing 10 mL of N,N-dimethylformamide (DMF) and reacted at 130 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the precipitate was diluted with deionized water, filtered, and washed with dimethyl sulfoxide (DMSO), water, and anhydrous ethanol, respectively. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0086] Example 5

[0087] 1 mmol of bipn prepared in Example 1 and 1.15 mmol of Ru(phen)Cl4 were added to a flask containing 50 mL of N,N-dimethylacetamide (DMAC). The mixture was reacted at 140 °C for 3 h under a nitrogen atmosphere. After cooling to room temperature, the mixture was diluted with deionized water, filtered, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and anhydrous ethanol, respectively. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0088] Example 6

[0089] 1 mmol of bipn prepared in Example 1 and 1.1 mmol of Ru(phen)Cl4 were added to a flask containing 15 mL of N,N-dimethylformamide (DMF) and 15 mL of N,N-dimethylacetamide (DMAC). The mixture was reacted at 150 °C for 24 h under a nitrogen atmosphere. After cooling to room temperature, the mixture was diluted with deionized water, filtered, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and anhydrous ethanol, respectively. The precipitate was then dried under vacuum at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0090] Comparative Example 1: Binuclear Complex

[0091] 1 mmol of bipn prepared in Example 1 and 2 mmol of Ru(phen)2Cl2 were added to a flask containing 30 mL of ethylene glycol and refluxed at 120 °C for 8 h under a nitrogen atmosphere. After cooling to room temperature, the mixture was diluted with deionized water, and a saturated ammonium hexafluorophosphate solution was added to completely precipitate the precipitate. The precipitate was filtered and thoroughly washed with deionized water, then dried under vacuum at 40 °C for 24 h to obtain the binuclear complex Ru-phen-bipn-2; yield: 1.34 g, efficiency: 85%; structure:

[0092] ESI-MS analysis spectrum as follows Figure 2 As shown; where ESI-MS(MeCN): m / z=359.56([M-4PF6] 4+),479.08([M-4PF6-H] 3+ ),527.74([M-3PF6] 3+ ),718.61([M-4PF6-2H] 2+ ),791.6([M-3PF6-H] 2+ MALDI-TOF analysis spectrum as shown Figure 3 As shown; the simulation revealed the following ion source fragments: peaks at m / z = 460.198, 497.197, and 532.179; specific fragment ions include: [Ru(phen)2-H] + [Ru(phen)2Cl] + and [Ru(phen)2Cl2].

[0093] Structural characterization:

[0094] 1. The Ru-phen-bipn-n prepared in the examples was subjected to MALDI-TOF analysis. The MALDI-TOF-MS spectra in the range of 200 to 2000 Da are shown below. Figure 4 As shown; the MALDI-TOF-MS spectra in the range of 2kDa to 10kDa are as follows. Figure 5 As shown.

[0095] Due to the poor solubility of the Ru-phen-bipn-n polymer material, its molecular weight was characterized using MALDI-TOF-MS. MALDI-TOF-MS spectra in the range of 200 to 2000 Da are shown below. Figure 4 The results show that Ru-phen-bipn-n has obvious fragment peaks. These fragment peaks are highly similar to the MALDI-TOF test results of its corresponding binuclear complex (Comparative Example 1) under the same experimental conditions. Simulation of these peaks can also identify the peak attribution.

[0096] Specifically, in the spectrum of Ru-phen-bipn-n Figure 4 Among them, fragment signals of 460.057, 497.029, 565.200, 846.173, 881.146, 1228.277, 1265.256, and 1409.347 correspond to the following ions: [Ru(phen)2-H]+, [Ru(phen)2Cl]+, and [Ru(phen)2Cl]. + [bipn+H] + [Ru(phen)(bipnH2)-H] + [Ru(phen)(bipnH)Cl] + [Ru(bipn)2-H] +[Ru(bipn)(bipnH)Cl] + and [Ru(phen)(bipn)(bipnH)-H] + .

[0097] When analyzing the high molecular weight region of Ru-phen-bipn-n in the range of 2kDa to 10kDa, some significant peaks were observed, corresponding to peaks at different degrees of polymerization, namely: m / z = 2257.47, 3098.50, and 3949.86. Based on theoretical simulations, these peaks correspond to the following ion: ([Ru2(phen)2(bipnH2)3] 4+ [M-3H] + ), ([Ru3(phen)3(bipnH)3(bipnH2)] 6+ [M-5H] + ), ([Ru4(phen)4(bipn)2(bipnH4)3] 8+ [M-7H] + These results demonstrate that polymers with different degrees of polymerization can be detected, and also indicate that the final product is a multi-component polymer containing different degrees of polymerization.

[0098] 2. The surface chemical state of the Ru-phen-bipn-n prepared in the examples was analyzed using XPS, and the results are as follows: Figure 6 As shown, a is the XPS total spectrum; b is the C1s narrow spectrum; and c is the N1s narrow spectrum.

[0099] The presence of C, O, N, and Ru elements in Ru-phen-bipn-n indicates successful material preparation. The narrow spectrum shows a shift in the C1s and N1s peaks of the polymer towards higher binding energies. This is likely because the linear ruthenium(II) polymer can continuously extend its chain length at both ends of the organic ligand. During polymerization, the proportion of the auxiliary ligand o-phenanthroline (phen), which has a lower binding energy, decreases with increasing chain length, ultimately leading to a shift in the binding energy of the naphthyl-linked ruthenium(II) metal-organic framework towards higher binding energies.

[0100] 3. XRD tests were performed on the Ru-phen-bipn-n prepared in the examples, and the results are as follows: Figure 7 As shown.

[0101] The XRD pattern of Ru-phen-bipn-n showed a significant broad peak at approximately 25.5°, indicating its low crystallinity and microcrystalline structure.

[0102] 4. The microstructure of Ru-phen-bipn-n prepared in the examples was tested, and the SEM images are shown below. Figure 8 As shown in the left figure; TEM image as follows Figure 8 As shown in the right figure; EDS plot as follows Figure 9 As shown.

[0103] SEM images of Ru-phen-bipn-n revealed a regular layered crystal structure with relatively large crystal sizes. TEM images further confirmed the layered stacked morphology of Ru-phen-bipn-n, indicating a high degree of order and good crystallinity. EDS elemental analysis showed that Ru, N, and C were uniformly distributed in Ru-phen-bipn-n, with the distribution of N and C elements consistent with the structure of the organic ligands, further confirming the effective binding of the organic ligands to the metal center.

[0104] 5. The thermal stability of Ru-phen-bipn-n prepared in the examples was analyzed. Thermogravimetric analysis (TGA) results are as follows: Figure 10 As shown.

[0105] The mass loss of Ru-phen-bipn-n is only 10.35% at 300℃ and 42.83% at 800℃. These results indicate that Ru-phen-bipn-n material exhibits good thermal stability, suggesting that the coordination between Ru(II) centers and ligands is relatively stable, and that it can maintain the stability of the framework structure at higher temperatures.

[0106] The organic ligand bipn of Ru-phen-bipn-n has a larger conjugated system due to its highly π-conjugated naphthyl structure, which enhances the stability of the molecular skeleton.

[0107] 6. UV absorption analysis was performed on Ru-phen-bipn-n prepared in the examples and Ru-phen-bipn-2 prepared in Comparative Example 1. UV-Vis absorption spectra of 20 μg / mL Ru-phen-bipn-n and Ru-phen-bipn-2 were measured in dichloromethane, ethanol, water, acetonitrile, and acetone, respectively. The results are as follows: Figure 11 As shown, a represents Ru-phen-bipn-2, and b represents Ru-phen-bipn-n. Solid-state UV-Vis-NIR spectroscopy was performed on Ru-phen-bipn-n, and the spectrum is shown below. Figure 12 As shown.

[0108] The results showed that both the binuclear complex of Comparative Example 1 and the linear polymer of the Examples exhibited similar UV absorption peaks. However, compared to the binuclear complex, the absorption peaks of the linear polymer at 275 nm, 360 nm, and 460 nm were relatively weaker. This variation is related to the structural characteristics of the ruthenium(II) linear polymer. During polymerization, as the polymer chain length increases, the content of the ligand phen gradually decreases, thus significantly weakening the absorption band at 275 nm generated by the π-π* transition induced by the phen moiety. Simultaneously, the relative content of the organic ligand bipn increases during polymerization, further promoting charge transfer within the ligand itself, thereby enhancing the absorption band at 360 nm. Furthermore, the absorption band at 460 nm generated by the MLCT transition also weakens due to the decreased ratio of phen to the metal center, resulting in a lower absorption peak at this wavelength for the linear polymer compared to its corresponding binuclear complex.

[0109] Solid-state UV-Vis-NIR absorption tests on Ru-phen-bipn-n showed that the polymer material exhibits effective absorption in the near-infrared spectral range, indicating its potential applications in near-infrared optical properties.

[0110] Example 7

[0111] PDMS precursors Sylgard 184a and Sylgard 184b were thoroughly mixed with ethyl acetate at a mass ratio of 0.25:0.25:10, resulting in a mixing volume of 10 mL. 10 mg of Ru-phen-bipn-n prepared in Example 1 was added, and the mixture was further dispersed by ultrasonication. Melamine sponge (MFS) was immersed in the resulting mixture until the solution was completely absorbed, and Ru-phen-bipn-n was adsorbed onto the surface of the MFS. Finally, the MFS was vacuum dried at 80 °C for 3 h to prepare a Janus evaporator loaded with Ru-phen-bipn-n.

[0112] Comparative Example 2

[0113] The difference between Comparative Example 2 and Example 7 is that Ru-phen-bipn-2 prepared in Comparative Example 1 was used instead of Ru-phen-bipn-n prepared in Example 1, while the other steps and methods were the same.

[0114] Performance testing:

[0115] 1. Photothermal conversion capability test

[0116] The Ru-phen-bipn-n powders prepared in the examples and the Ru-phen-bipn-2 powders prepared in Comparative Example 1 were tested under irradiation with 808 nm lasers of different power densities. The maximum surface temperature change of the Ru-phen-bipn-n powders is as follows: Figure 13 As shown; at 1W / cm 2 Cyclic photothermal experiments were conducted at power density, and the change in the highest surface temperature of Ru-phen-bipn-n powder was as follows: Figure 14 As shown; a real-world image of the infrared thermal imager demonstrating the effect of a single photothermal cycle is shown below. Figure 15 As shown.

[0117] Under 808nm laser irradiation, the surface temperature of the polymer powder sample rapidly increased within 5 seconds. After the laser was turned off, the sample temperature rapidly returned to room temperature within 10 seconds. With increasing laser power density, the highest achievable temperature on the material surface increased accordingly, exhibiting a clear positive correlation with laser power density. At 2W / cm²... 2 Under irradiation with an 808nm laser, the highest surface temperature of Ru-phen-bipn-n powder reached 265.3℃.

[0118] To further test the stability of the material's photothermal conversion, the samples were subjected to temperatures of 1 W / cm². 2 Cyclic photothermal experiments were conducted at power density. After five cycles, Ru-phen-bipn-n maintained a stable and rapid photothermal response with almost no loss in photothermal performance. No significant photobleaching was observed during prolonged laser irradiation, further validating its excellent photothermal stability. These experimental results demonstrate that these materials possess good photothermal conversion efficiency and stability, making them well-suited for applications in energy conversion and storage.

[0119] 2. Water evaporation capacity test

[0120] Ru-phen-bipn-n was loaded onto the photothermal coating of a Janus evaporator to investigate its effect in practical water evaporation applications. Commercially available hydrophilic melamine foam (MFS) was used as the evaporator platform, and the photothermal material was cured onto the top of the MFS using a curing agent. The thickness of the loaded photothermal material was fixed at 5 mm, and the total photothermal material loading was 10 mg, thus constructing a Janus evaporator with photothermal material at the top and blank MFS at the bottom.

[0121] The contact angle of the photothermal material layer of the Janus evaporator loaded with Ru-phen-bipn-n was 104.3°. Figure 16The bottom retains the hydrophilicity of the MFS (Metal-Film-Semiconductor-Fluorescent) material, consistent with the Janus evaporator's design philosophy of hydrophobic top and hydrophilic bottom. This ensures efficient water transport from the bottom layer to the photothermal material layer for evaporation while also enhancing the overall heat dissipation performance of the evaporator. Photothermal conversion performance tests of the Janus evaporator under 808nm laser irradiation showed a power density of 1W / cm². 2 At that time, the Janus evaporator surface temperature responded rapidly within 10 seconds and reached steady state within 60 seconds, which met our design expectations. The Ru-phen-bipn-n evaporator reached 145.3℃, compared to only 26.4℃ for pure MFS. Figure 17 This indicates that the Janus evaporator prepared in this application has a faster response and a more efficient photothermal conversion capability under 808nm laser irradiation.

[0122] The bottom of the evaporator was immersed in water, and the photothermal material layer was irradiated with an 808nm laser. Simultaneously, the mass loss of water and the corresponding evaporation rate were recorded. The change in water evaporation over time is shown in the figure below. Figure 18 As shown in Figure a; the evaporation rate changes with irradiation time as follows: Figure 18 As shown in b.

[0123] like Figure 18 As shown, the water evaporation rate of pure MFS under 808nm laser irradiation is only 0.25 kg·m³. -2 The evaporation efficiency is 0.50 kg·m³. -2 ·h -1 In contrast, the Janus evaporator loaded with the photothermal material Ru-phen-bipn-n exhibited a higher water evaporation rate and a water evaporation capacity of 0.76 kg·m³. -2 The evaporation efficiency is 1.50 kg·m³. -2 ·h -1 Compared to pure MFS, the evaporation performance is improved by 200%, which is a very considerable result.

[0124] To evaluate the salt precipitation resistance of the Janus evaporator under high water evaporation rates, the effect of different mass concentrations (0%, 5.0%, 10.0%, and 15.0% wt%) of NaCl solution on the evaporation performance of the Janus evaporator was investigated. The change in water evaporation rate over time for the Ru-phen-bipn-loaded Janus evaporator under different NaCl concentrations is shown in the figure below. Figure 19 As shown in Figure a; the evaporation rate of the Janus evaporator loaded with Ru-phen-bipn under different NaCl concentrations varies with irradiation time as shown in Figure a. Figure 19As shown in Figure b; the desalination rate of the Janus evaporator loaded with Ru-phen-bipn under different NaCl concentrations is as follows: Figure 20 As shown in Figure a; the desalination rate and evaporation rate of the Janus evaporator loaded with Ru-phen-bipn under different NaCl concentrations are as follows: Figure 20 As shown in b.

[0125] from Figure 19 It can be seen that the Janus evaporator loaded with Ru-phen-bipn-n has a water evaporation rate of 0.58 kg·m³ when evaporating a 5% NaCl solution. -2 The evaporation efficiency was 1.1619 ± 0.07883 kg·m³. -2 ·h -1 When evaporating a 15% NaCl solution, the water evaporation rate is 0.37 kg·m³. -2 The evaporation efficiency was 0.7418 ± 0.04709 kg·m³. -2 ·h -1 The test data above show that the Janus evaporator loaded with Ru-phen-bipn-n exhibits a decreasing evaporation performance with increasing NaCl concentration across different mass concentration gradients. We speculate that this result may be due to the partial adsorption of NaCl crystals into the interior of the Janus evaporator during evaporation, thus hindering water transport.

[0126] Even so, the Janus evaporator described above showed significantly better evaporation performance than the pure MFS in tests involving the evaporation of 15% NaCl solution. Furthermore, from... Figure 20 It can be seen that the desalination rate of NaCl solutions with different mass concentrations all exceeded 99.5%. Notably, no salt crystallization was observed throughout the experiment. These results demonstrate that the prepared Janus evaporator exhibits excellent water evaporation performance and superior salt resistance even under high salinity conditions, highlighting its potential in the field of efficient seawater desalination.

[0127] 3. Water purification capacity test

[0128] A simulation experiment of the actual seawater desalination process was conducted using the Janus evaporator prepared in Example 7. The experimental results showed that the four main ions (Na+, Na ... + Mg 2+ Ca 2+ K + The concentration of [a specific substance] in the condensate decreased to below 1 ppm after evaporation, significantly lower than the 10-500 ppm achievable by traditional membrane-based reverse osmosis methods. Figure 21 (a) In addition, Ru in water samples before and after evaporation2+ No significant change was detected in the concentration of Ru, indicating that the introduction of photothermal materials does not lead to the loss of photothermal resources. 2+ There is no leakage through the Janus evaporator, thus avoiding potential hazards to water bodies and human health.

[0129] Methyl orange (MO), Congo red (CR), and methylene blue (MB) were selected as model organic pollutants. Water evaporation was carried out using the Janus evaporator prepared in Example 7. Condensate was collected during the evaporation process and analyzed using UV-Vis absorption spectroscopy. The results are as follows: Figure 21 As shown; where b is CR; c is MO; d is MB.

[0130] Figure 21 The results show that the characteristic absorption peaks of MO at 465 nm, CR at 525 nm and MB at 663 nm completely disappeared in the condensate sample, indicating that these organic pollutants did not appear in the purified water during the evaporation process.

[0131] In summary, the organic ligands of Formula I in this application construct homogeneous linear polymers with ruthenium(II), retaining the excellent optical properties of ruthenium(II) complexes while combining the structural advantages of supramolecular MOFs materials, enabling the polymers to achieve efficient applications in photothermal conversion, water evaporation, and water purification.

[0132] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. The application of a naphthyl-linked ruthenium(II) metal-organic framework material as a photothermal conversion material, characterized in that, The naphthyl-linked ruthenium(II) metal-organic framework material is as follows: in the organic ligand of Formula I, two nitrogen atoms on the same phenanthroline are coordinated and connected to the same ruthenium atom, and in two adjacent organic ligands of Formula I, one phenanthroline is coordinated and connected to one ruthenium atom. Equation I; The preparation method of the naphthyl-linked ruthenium(II) metal-organic framework material is as follows. The organic ligand with the structure shown in Formula I reacts with Ru(phen)Cl4 in an organic solvent under an inert gas atmosphere to obtain the naphthyl-linked ruthenium(II) metal-organic framework material. The molar ratio of the organic ligand shown in Formula I to Ru(phen)Cl4 is 1:(1-1.2). The inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are 120-150℃ for 3-24 hours.

2. The application of the naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 as a photothermal conversion material, characterized in that, The organic solvent is one or a mixture of N,N-dimethylformamide and N,N-dimethylacetamide; the molar-volume ratio of the organic ligand with the structure shown in Formula I to the organic solvent is 1 mmol: (5-50) mL.

3. The application of the naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 as a photothermal conversion material, characterized in that, The reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and anhydrous ethanol respectively, and then dried under vacuum at 35-50℃.

4. The application of the naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 as a photothermal conversion material, characterized in that, The organic ligand with the structure shown in Formula I is prepared by reacting 1,10-phenanthroline-5,6-dione and 1,3-benzaldehyde in the presence of an ammonium salt.

5. The application according to claim 1, characterized in that, The naphthyl-linked ruthenium(II) metal-organic framework material is used as a photothermal conversion material for seawater desalination and wastewater purification.

6. An evaporator, characterized in that, The evaporator is a Janus evaporator, which includes the naphthyl-linked ruthenium(II) metal-organic framework material as described in claim 1.

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