Naphthyl-connected metal ruthenium (II) metal organic framework material, evaporator and preparation method and application of naphthyl-connected metal ruthenium (II) metal organic framework material

Abstract

The invention discloses a naphthyl-connected metal ruthenium (II) metal organic framework material, an evaporator and a preparation method and application of the naphthyl-connected metal ruthenium (II) metal organic framework material. Ruthenium (II) is used as a metal center, an organic ligand with a structure shown in a formula I and two end-group coordination groups is selected for reaction, the two end-group coordination groups are in coordination connection with a ruthenium complex precursor, linear coordination extension is achieved by means of ruthenium coordination characteristics, and the homogeneous linear polymer formed through naphthyl bridging is prepared. The metal ruthenium (II) supramolecular material has an 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 of the metal ruthenium (II) supramolecular material as a photo-thermal conversion material is realized; according to an evaporator loaded with the naphthyl-connected metal ruthenium (II) metal organic framework material, the water evaporation capacity 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, and the preparation method is efficient and economical.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal-organic complex functional materials, and particularly relates to a naphthalene-based metal ruthenium (II) metal-organic framework material, an evaporator, and a preparation method and application thereof. Background Art

[0002] The performance of metal-organic framework materials is closely related to their structures, and the functions of materials can be effectively regulated by fine modification of organic ligands. Some researchers have successfully constructed a series of MOFs materials with excellent performance by expanding the π-conjugated system of materials, introducing functional groups, or optimizing the geometric configuration of ligands. For example, expanding the π-conjugated system helps to enhance the light absorption ability and charge transfer efficiency of materials, while introducing specific functional groups can endow materials 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 ability for visible light and near-infrared light, resulting in insufficient photothermal conversion efficiency; on the other hand, the structural stability of materials is poor, and it is difficult to maintain long-term performance under high temperature or complex environments. These factors limit the wide application of photothermal materials in fields such as seawater desalination, wastewater treatment, and catalysis. Therefore, there is an urgent need to develop a MOFs material with both high photothermal conversion ability and excellent structural stability. Summary of the Invention

[0003] For the above reasons, the first object of the present invention is to provide a naphthalene-based metal ruthenium (II) metal-organic framework material, in which a homogeneous linear polymer structure is formed by the coordination of ruthenium (II) metal centers with organic ligands; the highly π-conjugated naphthalene structure enables the polymer to have a larger conjugated system, which not only enhances the optical properties of the ruthenium (II) metal complex but also has the structural advantages of supramolecular MOFs materials.

[0004] The second object of the present invention is to provide a preparation method for a naphthalene-based metal ruthenium (II) metal-organic framework material, which uses a ruthenium (II) complex with 1,10-phenanthroline as a metal precursor and directly reacts with an organic ligand to prepare a homogeneous linear polymer material; a simple synthesis preparation method is provided.

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

[0006] The fourth object of the present invention is to provide an evaporator with excellent water evaporation performance.

[0007] The first object of the present invention can be achieved by adopting the following technical solutions:

[0008] A naphthalene-based metal ruthenium (II) metal-organic framework material, in which two nitrogen atoms on the same phenanthroline in the organic ligand shown in Formula I are coordinatively bonded to the same ruthenium atom, and one phenanthroline on two adjacent organic ligands shown in Formula I is respectively coordinatively bonded to a ruthenium atom;

[0009]

[0010]

[0011] The second object of the present invention can be achieved by adopting the following technical solutions:

[0012] A preparation method of a naphthalene-based metal ruthenium (II) metal-organic framework material,

[0013] The organic ligand shown in Formula I reacts with Ru(phen)Cl4 in an organic solvent under an inert gas atmosphere to obtain the naphthalene-based metal ruthenium (II) metal-organic framework material.

[0014] Furthermore, the molar ratio of the organic ligand shown in Formula I to Ru(phen)Cl4 is 1:(1 - 1.2).

[0015] Furthermore, the organic solvent is one or a mixture of N,N-dimethylformamide and N,N-dimethylacetamide.

[0016] Furthermore, the molar volume ratio of the organic ligand shown in Formula I to the organic solvent is 1 mmol:(5 - 50) mL.

[0017] Furthermore, the inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are to react at 120 - 150 °C for 3 - 24 h.

[0018] Furthermore, the reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and absolute ethanol respectively, and vacuum dried at 35 - 50 °C.

[0019] Furthermore, the organic ligand 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.

[0020] The third object of the present invention can be achieved by adopting the following technical solutions:

[0021] Application of the naphthalene-based metal ruthenium (II) metal-organic framework material as a photothermal conversion material.

[0022] Furthermore, the naphthalene-based metal ruthenium (II) metal-organic framework material is used as a photothermal conversion material for seawater desalination and wastewater purification.

[0023] The fourth object of the present invention can be achieved by adopting the following technical solutions:

[0024] An evaporator, which is a Janus evaporator and includes the naphthalene-based metal ruthenium (II) metal-organic framework material described above.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. For the naphthalene-based metal ruthenium (II) metal-organic framework material of the present invention, ruthenium (II) is used as the metal center to form a new coordination metal center with an organic ligand, and a homogeneous linear polymer is formed through naphthalene bridging; it has the structure of MOFs materials, combines the excellent optical properties of metal ruthenium (II) complexes with the structural advantages of supramolecular MOFs materials, and realizes the application as a photothermal conversion material.

[0027] 2. For the preparation method of the naphthalene-based metal ruthenium (II) metal-organic framework material of the present invention, a complex precursor in which a phenanthroline group coordinates with metal ruthenium (II) reacts with an organic ligand having two terminal coordination groups. The two terminal coordination groups are respectively coordinated and connected with the ruthenium complex precursor, and linear coordination extension is realized by using the coordination characteristics of ruthenium, and a homogeneous linear polymer is prepared. The reaction synthesis route is simple, the yield is high, the preparation method is efficient and economical.

[0028] 3. For the application of the naphthalene-based metal ruthenium (II) metal-organic framework material of the present invention, the naphthalene-based metal ruthenium (II) metal-organic framework material of the present invention has high photothermal conversion ability and excellent structural stability, so it can be used as an excellent photothermal conversion material.

[0029] 4. An evaporator of the present invention, which is a Janus evaporator and is loaded with the naphthalene-based metal ruthenium (II) metal-organic framework material of the present application, shows a higher water evaporation amount and evaporation rate; the water evaporation amount is 0.76 kg·m -2 , and the evaporation efficiency reaches 1.50 kg·m -2 ·h -1 , and the improvement amplitude of the evaporation performance compared with that of pure MFS is 200%. Description of the Drawings

[0030] Figure 1 MALDI-TOF-MS spectrum of ligand bipn prepared in Example 1;

[0031] Figure 2ESI-MS spectrum of Ru-phen-bipn-2 prepared in Comparative Example 1;

[0032] Figure 3 MALDI-TOF-MS spectrum of Ru-phen-bipn-2 prepared in Comparative Example 1 in the range of 200 - 2000 m / z;

[0033] Figure 4 MALDI-TOF-MS spectrum of Ru-phen-bipn-n prepared in Example 2 in the range of 200 - 2000 m / z;

[0034] Figure 5 MALDI-TOF-MS spectrum of Ru-phen-bipn-n prepared in Example 2 in the range of 2k - 10k m / z;

[0035] Figure 6 XPS analysis diagram of Ru-phen-bipn-n prepared in Example 2, where a is the total XPS spectrum, b is the narrow spectrum of C1s, and c is the narrow spectrum of N1s;

[0036] Figure 7 XRD diagram of Ru-phen-bipn-n prepared in Example 2;

[0037] Figure 8 Microscopic morphology diagram of Ru-phen-bipn-n prepared in Example 2; the left figure is the SEM image; the right figure is the TEM image;

[0038] Figure 9 EDS element distribution diagram of Ru-phen-bipn-n prepared in Example 2;

[0039] Figure 10 TG diagram of thermal stability analysis of Ru-phen-bipn-n prepared in Example 2;

[0040] Figure 11 Ultraviolet absorption spectra of Ru-phen-bipn-2 prepared in Comparative Example 1 in different solvents (a) and ultraviolet absorption spectra of Ru-phen-bipn-n prepared in Example 2 in different solvents (b);

[0041] Figure 12 Solid UV-Vis-NIR spectrum of Ru-phen-bipn-n prepared in Example 2;

[0042] Figure 13 Photothermal performance diagram of Ru-phen-bipn-n prepared in Example 2 at different power densities;

[0043] Figure 14 Photothermal cycling test chart of Ru-phen-bipn-n prepared in Example 2 under 1 W / cm 2 ;

[0044] Figure 15 Real-time photothermal test image of Ru-phen-bipn-n prepared in Example 2 (808 nm, 1 W / cm 2 );

[0045] Figure 16 Water contact angle of the photothermal layer of the Janus evaporator prepared in Example 7;

[0046] Figure 17 Temperature change curve of the Janus evaporator prepared in Example 7 under 808 nm laser irradiation;

[0047] Figure 18 When the Janus evaporator prepared in Example 7 is in use, diagram of the change of water evaporation amount with irradiation time (a); diagram of the change of evaporation rate with irradiation time (b);

[0048] Figure 19 When the Janus evaporator prepared in Example 7 is in use under different salt concentrations, diagram of the change of water evaporation amount with irradiation time (a); diagram of the change of evaporation rate with irradiation time (b);

[0049] Figure 20 When the Janus evaporator prepared in Example 7 is in use under different salt concentrations, desalination rate diagram of the evaporator (a); bar chart of the desalination rate and evaporation rate of the evaporator (b);

[0050] Figure 21 Water quality purification performance diagram of the Janus evaporator prepared in Example 7; where a is the comparison diagram of ion concentrations of seawater before and after desalination; b is the ultraviolet absorption spectrum diagram of Congo red before and after purification; c is the ultraviolet absorption spectrum diagram of methyl orange before and after purification; d is the ultraviolet absorption spectrum diagram of methylene blue before and after purification. Detailed implementation manners

[0051] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0052] Ruthenium(II) metal complexes have excellent optical properties, but are mostly used in solution; even when prepared into mononuclear or polynuclear complexes, it is still difficult to expand their applications in solid powder form. MOFs are framework materials in terms of structure, and their molecular structure is still the coordination connection between metal and organic ligands, which has a similar metal-ligand structure to ruthenium(II) metal complexes. Therefore, the formation of ruthenium(II) MOFs materials, combined with the structural advantages of supramolecular MOFs materials, will expand the use of ruthenium(II) metal complexes in the solid state field.

[0053] Therefore, the present invention provides a naphthalene-based ruthenium(II) metal-organic framework material, an evaporator, and their preparation methods and applications.

[0054] A naphthalene-based ruthenium(II) metal-organic framework material, in which two nitrogen atoms on the same phenanthroline in the organic ligand shown in Formula I are coordinatively connected to the same ruthenium atom, and one phenanthroline on two adjacent organic ligands shown in Formula I is respectively coordinatively connected to a ruthenium atom;

[0055]

[0056] Ruthenium(II) can be hexacoordinated as the center. In this application, the organic ligand shown in Formula I is used to coordinatively connect with ruthenium(II), and two pyridine nitrogen atoms on the same phenanthroline are coordinatively connected to the same ruthenium atom; two phenanthrolines of one ligand shown in Formula I are respectively coordinatively connected to two different ruthenium(II); each ruthenium(II) is also coordinatively connected to one phenanthroline on another organic ligand shown in Formula I; thus, by coordinatively connecting ruthenium(II) with phenanthrolines of different ligands shown in Formula I, and by controlling the coordination of two different ligands with the same ruthenium(II), the ligands shown in Formula I are linearly connected.

[0057] As one of the embodiments, each ruthenium(II) is also coordinatively connected to two pyridine nitrogen atoms on a phenanthroline ligand. Thus, each ruthenium(II) forms a hexacoordinated structure; ruthenium(II) forms a new metal coordination center, which is connected by naphthalene groups to form a naphthalene-based ruthenium(II) metal-organic framework material.

[0058] As one of the embodiments, the naphthalene-based ruthenium(II) metal-organic framework material has the structure shown in Formula II:

[0059]

[0060] Among them, the content in the brackets is the repeating unit.

[0061] In this application, a homogeneous polymer material is formed by using ruthenium(II) as the metal center and infinitely bridging new metal centers through organic ligands. In terms of performance, while retaining the excellent optical properties of ruthenium(I) complexes, the structural advantages of supramolecular MOFs materials are combined to further expand their functionality.

[0062] This application also provides a method for preparing a naphthalene-linked ruthenium(II) metal-organic framework material. 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 naphthalene-linked ruthenium(II) metal-organic framework material.

[0063] In this application, ruthenium(II) reacts with the Ru(phen)Cl4 precursor containing one phenanthroline ligand. The remaining four coordination sites can coordinate with the phenanthroline groups of two different ligands with the structure shown in Formula I and extend the coordination in the linear direction; thereby linearly connecting different ligands with the structure shown in Formula I to form a naphthalene-linked ruthenium(II) metal-organic framework material. Wherein phen in Ru(phen)Cl4 is a 1,10-phenanthroline coordination group.

[0064] As one of the embodiments, Ru(phen)Cl4 can be purchased or synthesized. When synthesizing, RuCl3·H2O is in an aqueous hydrochloric acid solution, and reacts with 1,10-phenanthroline under an argon atmosphere and stirs in the dark, then reacts overnight, and the Ru(phen)Cl4 is obtained after post-treatment.

[0065] As one of the embodiments, 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.

[0066] 1,10-phenanthroline-5,6-dione reacts with naphthalene-2,6-dicarboxaldehyde and ammonium acetate in acetic acid solution, refluxes, and the organic ligand with the structure shown in Formula I is prepared after post-treatment.

[0067] As one of the embodiments, the molar ratio of the organic ligand with the structure shown in Formula I to Ru(phen)Cl4 is 1:(1 - 1.2).

[0068] As one of the embodiments, the organic solvent is one or a mixture of N,N-dimethylformamide and N,N-dimethylacetamide.

[0069] As one of the embodiments, 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.

[0070] As one of the embodiments, the inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are to react at 120-150 °C for 3-24 h.

[0071] As one of the embodiments, the reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and absolute ethanol respectively, and vacuum dried at 35-50 °C.

[0072] The present application also provides the use of the naphthyl-linked ruthenium(II) metal-organic framework material as a photothermal conversion material.

[0073] As one of the embodiments, the naphthyl-linked ruthenium(II) metal-organic framework material is used as a photothermal conversion material for seawater desalination and wastewater purification.

[0074] The present application also provides an evaporator, which is a Janus evaporator and includes the naphthyl-linked ruthenium(II) metal-organic framework material described above.

[0075] As one of the embodiments, the evaporator is a Janus evaporator loaded with a photothermal material on a melamine sponge.

[0076] As one of the embodiments, the photothermal material includes a composition of a PDMS precursor, a phenylene-linked ruthenium(II) homogeneous linear polymer material, and ethyl acetate.

[0077] As one of the embodiments, the PDMS precursor, the curing agent, and ethyl acetate are fully mixed; the naphthyl-linked ruthenium(II) metal-organic framework material is added and further mixed; the melamine sponge is immersed in the obtained mixed solution, completely absorbed, and vacuum dried to obtain a Janus evaporator loaded with a photothermal material.

[0078] The following is further illustrated with specific examples.

[0079] Example 1 Synthesis of ligand bipn

[0080] 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 the reaction was carried out at 117 °C for 5 h; after cooling to room temperature, the supernatant was removed by centrifugation, and the obtained precipitate was washed with deionized water and absolute 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, suction filtration was carried out, and the precipitate was washed with deionized water and absolute ethanol, and vacuum dried at 40 °C for 24 h to obtain the organic ligand having the structure shown in Formula I, which is 1,3-bis(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzene; named bipn; yield: 0.50 g, yield: 80%; the MALDI-TOF analysis result is as Figure 1 shown; the mass-to-charge ratio of the main peak is 566.82.

[0081] Example 2 Synthesis of linear polymer Ru-phen-bipn-n

[0082] 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), and the reaction was carried out at 150 °C for 6 h under a nitrogen atmosphere, cooled to room temperature, diluted with deionized water, suction filtered, and the precipitate was washed with dimethyl sulfoxide (DMSO), water and absolute ethanol respectively, and vacuum dried 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, yield 70%.

[0083] Example 3

[0084] 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 the reaction was carried out at 120 °C for 18 h under a nitrogen atmosphere, cooled to room temperature, diluted with deionized water, suction filtered, and the precipitate was washed with dimethyl sulfoxide (DMSO), water and absolute ethanol respectively, and vacuum dried at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0085] Example 4

[0086] 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). The reaction was carried out at 130 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, it was diluted with deionized water, filtered by suction, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and absolute ethanol respectively, and then dried in vacuo at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0087] Example 5

[0088] 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 reaction was carried out at 140 °C for 3 h under a nitrogen atmosphere. After cooling to room temperature, it was diluted with deionized water, filtered by suction, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and absolute ethanol respectively, and then dried in vacuo at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0089] Example 6

[0090] 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 reaction was carried out at 150 °C for 24 h under a nitrogen atmosphere. After cooling to room temperature, it was diluted with deionized water, filtered by suction, and the precipitate was washed with dimethyl sulfoxide (DMSO), water, and absolute ethanol respectively, and then dried in vacuo at 40 °C for 24 h to obtain the naphthyl-linked ruthenium(II) metal-organic framework material.

[0091] Comparative Example 1 Binuclear Complex

[0092] 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. Under a nitrogen atmosphere, it was refluxed at 120 °C for 8 h; after cooling to room temperature, it was diluted with deionized water, and a saturated ammonium hexafluorophosphate solution was added to completely precipitate the precipitate. It was filtered by suction and the precipitate was washed thoroughly with deionized water, and then dried in vacuo at 40 °C for 24 h; to obtain the binuclear complex Ru-phen-bipn-2; yield: 1.34 g, yield rate: 85%; the structure is:

[0093] The ESI-MS analysis spectrum is as Figure 2 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+ ). The MALDI-TOF analysis spectrum is as Figure 3 shown; among which the following ion source fragments can be identified through simulation: peaks at m / z = 460.198, 497.197, and 532.179; the specific fragment ions include: [Ru(phen)2 - H] + , [Ru(phen)2Cl] + and [Ru(phen)2Cl2].

[0094] Structure characterization:

[0095] 1. Perform MALDI-TOF analysis on the Ru-phen-bipn-n prepared in the example. The MALDI-TOF-MS spectrum in the range of 200 to 2000 Da is as Figure 4 shown; the MALDI-TOF-MS spectrum in the range of 2 kDa to 10 kDa is as Figure 5 shown.

[0096] Due to the poor solubility of the Ru-phen-bipn-n polymer material, MALDI-TOF-MS was used to characterize its molecular weight. From the results of the MALDI-TOF-MS spectrum Figure 4 in the range of 200 to 2000 Da, there are obvious fragment peak segments in Ru-phen-bipn-n. 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. At the same time, the peak attribution can also be identified by simulating these peaks.

[0097] Specifically, in the spectrum Figure 4 of Ru-phen-bipn-n, the fragment signals of 460.057, 497.029, 565.200, 846.173, 881.146, 1228.277, 1265.256, and 1409.347 respectively correspond to the following ions: [Ru(phen)2 - H]+, [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] + 。

[0098] When analyzing the high molecular weight region of Ru-phen-bipn-n in the range of 2 kDa to 10 kDa, some significant peaks were observed, corresponding to peaks of different degrees of polymerization, which were: m / z = 2257.47, 3098.50 and 3949.86 respectively. According to the theoretical simulation results of these peaks, they respectively correspond to the following ions: ([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 indicate that polymers with different degrees of polymerization can be detected. At the same time, they also indicate that the final product is a multi-component polymer containing different degrees of polymerization.

[0099] 2. The surface chemical state of the Ru-phen-bipn-n prepared in the examples was analyzed by XPS, and the results are as Figure 6 shown, where a is the XPS total spectrum; b is the C1s narrow spectrum; c is the N1s narrow spectrum.

[0100] Elements C, O, N and Ru can be detected in Ru-phen-bipn-n, indicating that the material preparation was successful; the narrow spectrum shows that the C1s and N1s peaks of the polymer shifted towards higher binding energies. This may be because the linear polymer of ruthenium(II) can continuously extend the chain lengths at both ends of the organic ligand. During the polymerization process, the content ratio of the auxiliary ligand o-phenanthroline (phen) with a lower binding energy of itself will decrease as the chain length increases, and finally lead to the binding energy of the ruthenium(II) metal-organic framework material connected by naphthyl groups moving towards higher binding energies.

[0101] 3. The Ru-phen-bipn-n prepared in the examples was tested by XRD, and the results are as Figure 7 shown.

[0102] The XRD pattern of Ru-phen-bipn-n showed a significant broad peak at about 25.5°, indicating its low crystallinity and presenting a microcrystalline structure..

[0103] 4. The microscopic morphology of the Ru-phen-bipn-n prepared in the examples was tested, and the SEM image is as Figure 8as shown in the left figure; the TEM image is as Figure 8 shown in the right figure; the EDS image is as Figure 9 shown.

[0104] The SEM image of Ru-phen-bipn-n shows that it presents a regular layered crystal structure with relatively large crystal sizes; the TEM image further indicates the layered stacked morphological structure of Ru-phen-bipn-n, suggesting that the sample has a high degree of order and good crystallinity. EDS elemental analysis shows that Ru, N, and C are uniformly distributed in Ru-phen-bipn-n, and the distributions of N element and C element are consistent with the structure of the organic ligand, further confirming the effective binding of the organic ligand to the metal center.

[0105] 5. Thermal stability analysis was performed on the Ru-phen-bipn-n prepared in the example, and the thermogravimetric analysis (TGA) test results are as Figure 10 shown.

[0106] The mass loss of Ru-phen-bipn-n is only 10.35% at 300 °C and 42.83% at 800 °C. These results indicate that the Ru-phen-bipn-n material exhibits good thermal stability, suggesting that the coordination bond between the Ru(II) center and the ligand is relatively stable and can maintain the stability of the framework structure at higher temperatures.

[0107] The organic ligand bipn of Ru-phen-bipn-n has a highly π-conjugated naphthyl structure, which gives it a larger conjugated system and enhances the stability of the molecular framework.

[0108] 6. UV absorption analysis was performed on the Ru-phen-bipn-n prepared in the example and the Ru-phen-bipn-2 prepared in Comparative Example 1. The UV-Vis absorption spectra of 20 μg / mL of Ru-phen-bipn-n and Ru-phen-bipn-2 were tested in dichloromethane, ethanol, water, acetonitrile, and acetone respectively; the results are as Figure 11 shown, where a is Ru-phen-bipn-2 and b is Ru-phen-bipn-n. Solid UV-Vis-NIR testing was performed on Ru-phen-bipn-n, and the spectrum is as Figure 12 shown.

[0109] The results show that both the binuclear complex of Comparative Example 1 and the linear polymer of the Example exhibit similar ultraviolet absorption peaks. However, compared with the binuclear complex, the absorption peaks of the linear polymer at 275 nm, 360 nm, and 460 nm are relatively weak. This change is related to the structural characteristics of the ruthenium(II) linear polymer. During the polymerization process, as the polymer chain length increases, the content of the ligand phen gradually decreases. Therefore, the absorption band at 275 nm generated by the π-π* transition caused by the phen part is significantly weakened. At the same time, due to the relative increase in the content of the organic ligand bipn during the polymerization process, this further promotes the charge transfer of the ligand itself, resulting in an enhanced absorption band at 360 nm. In addition, the absorption band at 460 nm generated by the MLCT transition also becomes weaker due to the decrease in the ratio of phen to the metal center, causing the absorption peak of the linear polymer at this wavelength to be lower than that of its corresponding binuclear complex.

[0110] The results of the solid ultraviolet-visible-near-infrared light absorption test on Ru-phen-bipn-n show that the polymeric material has effective absorption in the near-infrared spectral range, indicating its potential application in the optical properties in the near-infrared region.

[0111] Example 7

[0112] The PDMS precursors Sylgard 184a, Sylgard 184b, and ethyl acetate were fully mixed at a mass ratio of 0.25:0.25:10, and the mixed volume was 10 mL; 10 mg of Ru-phen-bipn-n prepared in Example 1 was added and further mixed by ultrasonic dispersion; the melamine sponge (MFS) was immersed in the obtained mixed solution until the solution was completely absorbed, and Ru-phen-bipn-n was adsorbed on the surface layer 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.

[0113] Comparative Example 2

[0114] 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, and the other steps and methods were the same.

[0115] Performance test:

[0116] 1. Photothermal conversion ability test

[0117] The Ru-phen-bipn-n prepared in the examples and the Ru-phen-bipn-2 powder prepared in Comparative Example 1 were tested under 808 nm laser irradiation with different power densities. The change in the maximum surface temperature of the Ru-phen-bipn-n powder is as shown in Figure 13 ; A cyclic photothermal experiment was carried out at a power density of 1 W / cm 2 . The change in the maximum surface temperature of the Ru-phen-bipn-n powder is as shown in Figure 14 ; The actual infrared thermal imager picture of the effect of one photothermal cycle is as shown in Figure 15 .

[0118] Under 808 nm laser irradiation, the surface temperature of the polymer powder sample rises rapidly within 5 seconds. After the laser is turned off, the temperature of the sample quickly returns to room temperature within 10 seconds. As the laser power density increases, the maximum temperature that the material surface can reach rises accordingly, showing an obvious positive correlation with the laser power density. Under 808 nm laser irradiation with a power density of 2 W / cm 2 , the maximum surface temperature of the Ru-phen-bipn-n powder reached 265.3 °C.

[0119] To further test the stability of the photothermal conversion of the material, the samples were subjected to cyclic photothermal experiments at a power density of 1 W / cm 2 respectively. After five cycle tests, Ru-phen-bipn-n still maintained a stable and rapid photothermal response. At the same time, its photothermal performance hardly decreased. During the long-term laser irradiation process, no obvious photo-bleaching phenomenon occurred in the samples, which further verified its excellent photothermal stability. The above experimental results show that these materials have good photothermal conversion efficiency and stability, and can be well applied in the fields of energy conversion and storage, etc.

[0120] 2. Water evaporation capacity test

[0121] Ru-phen-bipn-n was loaded on the photothermal coating of the Janus evaporator to explore its effect in the practical application field of water evaporation. A commercially available hydrophilic melamine foam (MFS) was selected as the evaporator platform, and the photothermal material was cured on the top of the MFS through a curing agent. The thickness of the loaded photothermal material was fixed at 5 mm during the preparation, and the total loading amount of the photothermal material was 10 mg, constructing a Janus evaporator with a photothermal material at the top and a blank MFS at the bottom.

[0122] The contact angles of the photothermal material layer of the Janus evaporator loaded with Ru-phen-bipn-n were 104.3°( Figure 16) At the bottom, the hydrophilicity of MFS is maintained, which conforms to the design concept of a Janus evaporator with a hydrophobic top and a hydrophilic bottom. While ensuring the efficient transportation of water from the bottom layer to the layer containing the photothermal material for water evaporation, it also enhances the overall heat dissipation performance of the evaporator. The Janus evaporator was placed under an 808 nm laser for testing the photothermal conversion performance. The results showed that under the irradiation of an 808 nm laser, when the power density was 1 W / cm 2 , the surface temperature of the Janus evaporator responded rapidly within 10 seconds and reached a steady state within 60 seconds, and the results met our design expectations. Among them, the temperature of Ru-phen-bipn-n was 145.3 °C. In contrast, the surface temperature of pure MFS was only 26.4 °C ( Figure 17 ). This indicates that the Janus evaporator prepared in this application has the ability of more rapid response and more efficient photothermal conversion under the irradiation of an 808 nm laser.

[0123] Immerse the bottom end of the evaporator in water and irradiate the photothermal material layer with an 808 nm laser, and at the same time record the mass loss of water and the corresponding evaporation rate. The change of water evaporation with time is as shown in Figure 18 a; the change of evaporation rate with irradiation time is as shown in Figure 18 b.

[0124] As shown in Figure 18 , the water evaporation amount of pure MFS under the irradiation of an 808 nm laser was only 0.25 kg·m -2 , and the evaporation efficiency was 0.50 kg·m -2 ·h -1 . In contrast, the Janus evaporator loaded with the photothermal material Ru-phen-bipn-n showed a higher water evaporation amount and evaporation rate. The water evaporation amount was 0.76 kg·m -2 , and the evaporation efficiency was 1.50 kg·m -2 ·h -1 , and the evaporation performance improvement compared to pure MFS was 200%, and this improvement is a very remarkable result.

[0125] To evaluate the anti-salt precipitation performance of the Janus evaporator at high water evaporation amounts, the effects of NaCl solutions with different mass concentrations (0%, 5.0%, 10.0%, 15.0% wt%) on the evaporation performance of the Janus evaporator were evaluated. The change of water evaporation amount of the Janus evaporator loaded with Ru-phen-bipn at different NaCl concentrations with time is as shown in Figure 19 a; the change of evaporation rate of the Janus evaporator loaded with Ru-phen-bipn at different NaCl concentrations with irradiation time is as shown in Figure 19As shown in b; the desalination rates of the Janus evaporator loaded with Ru-phen-bipn at different NaCl concentrations are as Figure 20 shown in a; the desalination rates and evaporation rates of the Janus evaporator loaded with Ru-phen-bipn at different NaCl concentrations are as Figure 20 shown in b.

[0126] From Figure 19 it can be known that when the Janus evaporator loaded with Ru-phen-bipn-n evaporates a 5% NaCl solution, the water evaporation amount is 0.58 kg·m -2 , and the evaporation efficiency is 1.1619 ± 0.07883 kg·m -2 ·h -1 , when evaporating a 15% NaCl solution, the water evaporation amount is 0.37 kg·m -2 , and the evaporation efficiency is 0.7418 ± 0.04709 kg·m -2 ·h -1 . It can be seen from the above test data that the Janus evaporator loaded with Ru-phen-bipn-n shows a trend of decreasing evaporation performance with the increase of the solution concentration when in NaCl solutions with different mass concentration gradients. We speculate that such a result may be due to the partial adsorption of NaCl crystals inside the Janus evaporator during the evaporation process, which hinders the transportation of water.

[0127] Even so, the test results of the above Janus evaporator in evaporating a 15% NaCl solution are significantly better than the evaporation performance of pure MFS. In addition, from Figure 20 it can be known that the desalination rates for NaCl solutions with different mass concentrations all exceed 99.5%. It is worth noting that no salt crystal crystallization phenomenon was observed during the entire experimental process. These results indicate that the prepared Janus evaporator can exhibit excellent water evaporation performance and excellent salt resistance even under high salinity conditions, highlighting its potential in the field of efficient seawater desalination applications.

[0128] 3. Water quality purification ability test

[0129] A simulation experiment on the actual seawater desalination process was carried out using the Janus evaporator prepared in Example 7. The experimental results show that the concentrations of the four main ions (Na + , Mg 2+ , Ca 2+ , K + ) in the seawater sample collected from the East China Sea are all reduced to below 1 ppm in the condensed water after evaporation, significantly lower than the 10 - 500 ppm that can be achieved by the traditional membrane-based reverse osmosis method ( Figure 21 a). In addition, the Ru in the water sample before and after evaporation2+ No significant change in concentration was detected, indicating that the introduction of the photothermal material does not cause loss of photothermal resources, while Ru 2+ will not leak through the Janus evaporator, thus avoiding potential hazards to water bodies and human health.

[0130] Methyl orange (MO), congo red (CR) and methylene blue (MB) were selected as model organic pollutants; the Janus evaporator prepared in Example 7 was used for water evaporation, the condensed water was collected during the evaporation process, and ultraviolet-visible absorption spectroscopy was used for analysis. The results are as Figure 21 shown; where b is CR; c is MO; d is MB.

[0131] Figure 21 It is shown that the characteristic absorption peaks of MO at 465 nm, CR at 525 nm and MB at 663 nm all completely disappeared in the condensed water samples, indicating that these organic pollutants did not appear in the purified water during the evaporation process.

[0132] In summary, the organic ligand of the structure shown in Formula I of this application constructs a homogeneous linear polymer with ruthenium(II) metal, while retaining the excellent optical properties of the ruthenium(II) metal complex and combining the structural advantages of the supramolecular MOFs material, enabling the polymer to achieve efficient applications in the fields of photothermal conversion, water evaporation and water purification.

[0133] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A naphthyl-linked ruthenium(II) metal-organic framework material, characterized in that, In the organic ligand with the structure shown in Formula I, two nitrogen atoms on the same phenanthroline coordinate and connect with the same ruthenium atom, and one phenanthroline on two adjacent organic ligands with the structure shown in Formula I respectively coordinates and connects with one ruthenium atom; 2. A preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material, characterized in that 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.

3. The preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material according to claim 2, characterized in that the molar ratio of the organic ligand with the structure shown in Formula I to Ru(phen)Cl4 is 1:(1 - 1.2).

4. The preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material according to claim 2, 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.

5. The preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material according to claim 2, characterized in that the inert gas atmosphere is a nitrogen or argon atmosphere; the reaction conditions are to react at 120 - 150 °C for 3 - 24 h.

6. The preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material according to claim 2, characterized in that the reaction includes a separation and washing process; after solid-liquid separation, the solid is washed with dimethyl sulfoxide, water, and absolute ethanol respectively, and vacuum dried at 35 - 50 °C.

7. The preparation method of a naphthyl-linked ruthenium(II) metal-organic framework material according to claim 2, 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-benzenedicarboxaldehyde in the presence of an ammonium salt.

8. Application of the naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 and the naphthyl-linked ruthenium(II) metal-organic framework material prepared by the preparation method of the naphthyl-linked ruthenium(II) metal-organic framework material according to any one of claims 2 - 7 as a photothermal conversion material.

9. The application according to claim 8, wherein The naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 or the naphthyl-linked ruthenium(II) metal-organic framework material prepared by the preparation method of the naphthyl-linked ruthenium(II) metal-organic framework material according to any one of claims 2 - 7 is used as a photothermal conversion material for seawater desalination and wastewater purification.

10. An evaporator, characterized in that, The evaporator is a Janus evaporator, and the evaporator includes the naphthyl-linked ruthenium(II) metal-organic framework material according to claim 1 or the naphthyl-linked ruthenium(II) metal-organic framework material prepared by the preparation method of the naphthyl-linked ruthenium(II) metal-organic framework material according to any one of claims 2 - 8.

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