Synthesis method of porphyrin coherent hybrid bimetallic sulfide and photocatalytic application of porphyrin coherent hybrid bimetallic sulfide

Abstract

The invention discloses a synthesis method of a porphyrin coherent hybrid bimetallic sulfide and photocatalytic application of the porphyrin coherent hybrid bimetallic sulfide. Porphyrin molecules are combined with metal ion active sites in the bimetallic sulfide through coordinate bonds on the basis of a coherent hybrid strategy to form an inorganic-organic hybrid structure, namely the porphyrin coherent hybrid bimetallic sulfide. Wherein the porphyrin derivative has a high molar absorption coefficient, excellent photosensitivity and structural stability, and is effectively combined with metal ion active sites in the bimetallic sulfide through a strong coordinate bond to form an inorganic-organic hybrid simulated hydrogenase structure, and the unique electron conjugated structure of the porphyrin molecule can be used as an effective charge transfer platform; the charge separation efficiency is greatly improved, so that the photocatalytic hydrogen production performance is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of design and synthesis of inorganic-organic hybrid structures, and specifically relates to a synthesis method of porphyrin coherent hybrid bimetallic sulfide and a photocatalytic application thereof. Background Art

[0002] In nature, photosynthetic bacteria and algae can convert metabolic hydrogen protons into a large amount of hydrogen every year with the cooperation of specific functional components in hydrogenase, directly converting solar energy into renewable chemical fuels (a) S. Zhao, L. Shen, X. Li, Q. Tao, Z. Li, C. Xu, C. Zhou, Y. Yang, M. Sang, G. Han, L.-J. Yu, T. Kuang, J.-R. Shen, W. Wang, Nature Communications 2023, 14; 8164; b) KERedding, J. Appel, M. Boehm, W. Schuhmann, MM Nowaczyk, I. Yacoby, K. Gutekunst, Trends in Biotechnology 2022, 40, 1313-1325.). Inspired by the efficient catalytic mechanism of hydrogenase, designing and synthesizing artificial hydrogenase is an effective way to utilize clean solar energy. At present, the design of artificial hydrogenases mainly focuses on regulating various organic molecular ligands from the periphery of the central metal, which can effectively adjust the coordination environment of the metal active center, thereby affecting the catalytic performance of the constructed system. Although these reported simulated hydrogenase structures have great potential, the organic components in these systems lack sufficient photostability and cannot maintain long-term sustainable photocatalytic performance, which makes the artificial hydrogenase system still face many challenges. In addition to the synthetic challenges, the main optimization goal of artificial hydrogenases is to develop multimetallic active sites with tunable redox properties, or to establish efficient charge transfer channels between electron donors (EDs), photosensitizers (PSs) and active sites in the constructed system (a) M. Sensi, C. Baffert, C. Greco, G. Caserta, C. Gauquelin, L. Saujet, M. Fontecave, S. Roy, V. Artero, P. Soucaille, I. Meynial-Salles, H. Bottin, L. de Gioia, V. Fourmond, C. Leger, L. Bertini, Journal of the American Chemical Society 2016, 138, 13612-13618; b) S. Ott, M. Kritikos, B. LC Sun, Angewandte Chemie-International Edition 2003, 42, 3285-3288.). Therefore, designing hydrogenase model compounds with simpler composite structures and higher photostability has more practical significance for studying large-scale photocatalytic conversion of solar energy to hydrogen.

[0003] In addition to various organic components, inorganic materials have also been reported to be used to construct artificial hydrogenase systems and show unique advantages. In addition to their unique specific surface area and light-harvesting capabilities, some inorganic semiconductor nanomaterials also have good photosensitivity and photocatalytic properties, making them ideal functional components for preparing artificial hydrogenases. In particular, multi-metallic nanomaterials have adjustable energy band structures and strong reduction activity, which are more conducive to photocatalytic hydrogen production. It is well known that in natural hydrogenases, light-harvesting complexes and electron transport chains are tightly organized around metal active sites, which facilitates efficient light harvesting and rapid charge transfer (a) M. Wang, L. Chen, X. Li, L. Sun, Dalton Transactions 2011, 40, 12793-12800; b) J. W. Peters, W. N. Lanzilotta, B. J. Lemon, L. C. Seefeldt, Science (New York, NY) 1998, 282, 1853-1858; c) Y. Nicolet, C. Piras, P. Legrand, C. E. Hatchikian, J. C. Fontecilla-Camps, Structure (London, England: 1993) 1999, 7, 13-23.). Therefore, the ternary system integrating electron donors, photosensitizers and multimetal sites (ED-PS-multimetal sites) constitutes the most realistic functional mimetic of natural hydrogenases. The organic components in artificial ternary organic-inorganic composite systems often act as photosensitizers and electron donors to enhance the light absorption capacity of the entire system and provide compensating electrons for metal sites. However, most of these organic and inorganic components are integrated only through surface deposition and coupling, which makes it impossible to establish effective charge transfer pathways at the molecular level between them, resulting in unsatisfactory photocatalytic hydrogen evolution performance. Therefore, the focus of designing organic-inorganic simulated hydrogenases in the future should not only focus on enhancing the functions of independent components, but also consider the direct and close collaboration between different components, such as establishing effective charge transfer pathways between photosensitizers and multi-metal sites. The coherent hybridization strategy is an ideal synthetic scheme that can coordinate the metal ion active sites with organic photosensitizers to establish a fast charge transfer channel (a) F. Zhang, PC Sherrell, W. Luo, J. Chen, W. Li, J. Yang, M. Zhu, Advanced Science 2021, 8, 2102859; b) X. Qi, Y. Xiang, E. Cai, X. Ge, X. Chen, W. Zhang, Z. Li, J. Shen, Coordination Chemistry Reviews 2023, 496, 215426.).There is currently no literature report on the synthesis of inorganic-organic hybrid hydrogenase mimics based on coherent hybridization strategies. Summary of the invention

[0004] The purpose of the present invention is to provide a porphyrin coherent hybrid bimetallic sulfide and a synthesis method thereof, which utilizes the coherent hybridization principle to synthesize a multimetallic ZnCdS 2 (CZS) nanomaterials were combined with platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (PtTCPP) according to an in situ synthesis method to design and construct an artificial hybrid photocatalytic hydrogen production system, namely porphyrin coherent hybrid bimetallic sulfide. Among them, the porphyrin derivative has a high molar absorption coefficient, excellent photosensitivity and structural stability, and effectively combines with the metal ion active sites in the bimetallic sulfide through a strong coordination bond to form an inorganic-organic hybrid simulated hydrogenase structure. In this form, the coordinated porphyrin can not only regulate the reaction activity of the multi-metal center, but also act as a stable photosensitizer and efficient charge transfer carrier between the catalytic active sites due to its rigid π-conjugated structure. Therefore, the ED-PS-multi-metal site model can be realized in such a simple framework. The photocatalytic hydrogen production performance of this photocatalytic hydrogen production system is significantly enhanced, and the hydrogen production rate reaches 86.7mmol·g -1 ·h -1 , which is about 4 times that of single CZS. In addition, the photocatalytic hydrogen production system also exhibits an extraordinary apparent quantum efficiency (AQE) of up to 82.95%. Kelvin probe force microscopy proves that the huge internal electric field established by the coherent hybridization of PtTCPP does play a key role in improving the separation and transfer of photogenerated carriers. This is the first time that the synergistic coherent hybridization between inorganic semiconductors and organic functional molecules has been used to construct a homogeneous inorganic-organic hybrid simulated hydrogenase system.

[0005] The present invention adopts the following technical scheme to achieve the above-mentioned purpose: porphyrin coherent hybrid bimetallic sulfide, which combines porphyrin molecules with metal ion active sites in bimetallic sulfide through coordination bonds based on the coherent hybridization strategy to form an inorganic-organic hybrid structure, namely porphyrin coherent hybrid bimetallic sulfide (CZS / PtTCPP), and its structure is:

[0006]

[0007] Further defined, the porphyrin molecule is hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin; the bimetallic sulfide is bimetallic ZnCdS 2 Nanomaterials.

[0008] The method for synthesizing the porphyrin coherent hybrid bimetallic sulfide of the present invention comprises the following specific steps: adding a soluble zinc salt, a soluble cadmium salt and a soluble sulfur source into a hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin system by an in-situ synthesis method, and synthesizing an inorganic-organic hybrid biomimetic hydrogenase structure, namely the porphyrin coherent hybrid bimetallic sulfide, based on a coherent hybridization strategy.

[0009] The method for synthesizing the porphyrin coherent hybrid bimetallic sulfide of the present invention comprises the following specific steps:

[0010] Step S1: adding 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and an excess of metal platinum salt to a benzonitrile solvent, heating under reflux under inert gas protection until the raw materials react completely, and separating the reaction solution by column chromatography and purifying by recrystallization to obtain hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin;

[0011] Step S2: adding a soluble zinc salt and a soluble cadmium salt to a hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin solution, stirring the mixture at 20-40° C. for 4-8 hours, then adding a soluble sulfur source, and continuing to stir the mixture at 20-40° C. for 20-30 hours to obtain the target product, porphyrin coherent hybrid bimetallic sulfide.

[0012] It is further defined that the specific synthesis route of the hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin in step S1 is:

[0013]

[0014] Further defined, the metal platinum salt in step S1 is PtCl 2 The molar ratio of 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin to metal platinum salt is 1:2-5.

[0015] It is further defined that the soluble zinc salt in step S2 is Zn(NO 3 ) 2 6H 2 O; the soluble cadmium salt is CdCl 2 ; The soluble sulfur source is Na 2 S.9H 2 O; the feeding molar ratio of the soluble zinc salt, the soluble cadmium salt and the soluble sulfur source is 1:0.5~1:1.5~2.

[0016] It is further defined that the specific synthesis route of the porphyrin coherent hybrid bimetallic sulfide in step S2 is:

[0017]

[0018] It is further defined that the hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin solution in step S2 is obtained by dissolving hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin in a mixed solvent of N,N-dimethylformamide and deionized water, wherein the volume ratio of N,N-dimethylformamide to deionized water in the mixed solvent is 1:9.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: the present invention has relatively few synthesis steps, high yield, mild preparation conditions, and the porphyrin molecule itself as a building unit has unique physical and chemical properties. Porphyrin can not only regulate the coordination environment of the metal active center, but also serve as a stable and efficient charge transfer carrier, achieving multi-purpose integration and simplifying the model; at the same time, the bimetallic sulfide-ZnCdS 2 As heteronuclear bimetallic active centers, they have a similar bimetallic active center structure to that in hydrogenases, with metal centers bridged by S atoms and coordinated by carboxyl groups in porphyrins. The porphyrin system and the metal active center are effectively combined as a whole, which is more conducive to the synergistic effect of the two. This makes them exhibit excellent photocatalytic hydrogen production performance and good potential application value when participating in photocatalytic hydrogen production as biomimetic hydrogenase structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the transmission electron microscopy image of CZS / PtTCPP prepared in Example 1.

[0021] Figure 2 These are optical path photographs of the CZS / PtTCPP aqueous solution system and the CZS aqueous solution system prepared in Example 1 under laser irradiation.

[0022] Figure 3 X-ray diffraction patterns of CZS / PtTCPP and CZS prepared in Example 1.

[0023] Figure 4 This is the UV-visible absorption spectra of CZS / PtTCPP, PtTCPP and CZS prepared in Example 1.

[0024] Figure 5 Fourier transform infrared spectra of CZS / PtTCPP, PtTCPP and CZS prepared in Example 1.

[0025] Figure 6 This is the photocatalytic hydrogen production performance diagram of CZS / PtTCPP, PtTCPP, Mix-CZS-PtTCPP and CZS prepared in Example 1.

[0026] Figure 7This is the stability diagram of the photocatalytic hydrogen production performance of CZS / PtTCPP prepared in Example 1. DETAILED DESCRIPTION

[0027] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0028] Example 1

[0029] Synthesis of PtTCPP

[0030]

[0031] PtCl 2 (120 mg, 0.45 mmol) and TCPP (119 mg, 0.15 mmol) were added into a 50 mL round bottom dry flask containing anhydrous benzonitrile. 2 Degas for 20 min under N 2 The reaction was stirred and refluxed under protective atmosphere, and then the solvent was removed in vacuo. 2 Cl 2 The crude product was purified by silica gel column chromatography using 4% paraformaldehyde and 1% hexane as eluents. 2 Cl 2 / hexane recrystallization to obtain Pt (II) porphyrin complex crystals with a yield of 46%. 1H NMR (400MHz, DMSO-d6) δ 13.31 (s, 4H), 8.81 (s, 8H), 8.37 (d, J = 8.1 Hz, 9H), 8.30 (d, J = 8.0 Hz, 8H).

[0032] Example 2

[0033] Synthesis of Porphyrin Coherent Hybrid Bimetallic Sulfide (CZS / PtTCPP)

[0034]

[0035] PtTCPP (2 mg) was dissolved in a mixed solvent of DMF and deionized water (volume ratio 1:9, 100 mL) to obtain a PtTCPP solution. Zn(NO 3 ) 2 6H 2 O (6 mmol) and CdCl 2 (4 mmol), stirred in a 30°C water bath for 6 h, and then Na 2 S.9H 2O (10 mmol) was added and stirred for 24 h, and the obtained nanoparticles were collected by high-speed centrifugation, washed with deionized water, and finally the sample was placed in a vacuum drying oven and dried to obtain the target product porphyrin coherent hybrid bimetallic sulfide (CZS / PtTCPP).

[0036] Figure 1 The transmission electron microscopy image of the prepared CZS / PtTCPP is Figure 1 It can be seen that the average particle size of the CZS / PtTCPP nanomaterial synthesized by PtTCPP regulation is about 4.6 nm.

[0037] Figure 2 The figure shows the dispersibility comparison of different samples. It can be seen that CZS / PtTCPP nanomaterials can be evenly dispersed in aqueous solution, and a significant Tyndall effect can be observed. In contrast, CZS nanomaterials quickly aggregate and sink to the bottom of the bottle in aqueous solution, and no Tyndall effect can be observed, indicating that CZS / PtTCPP nanomaterials have good dispersion state and stability.

[0038] Figure 3 The X-ray diffraction patterns of the prepared CZS / PtTCPP and CZS show that ZnCdS 2 There is no significant difference between CZS and CZS / PtTCPP in X-ray diffraction (XRD) patterns. The characteristic peaks of the two samples are similar to those of Cd 0.5 Zn 0.5 The (101), (112) and (103) crystal planes of S (JCPDS: 97-106-9186) completely overlap, indicating that the modification of porphyrin molecules did not destroy the crystal structure of CZS.

[0039] Figure 4 The UV-visible absorption spectra of the prepared CZS / PtTCPP, PtTCPP and CZS. The successful combination of PtTCPP and CZS was confirmed by UV-visible absorption spectrum. It can be seen from the figure that the characteristic peaks of PtTCPP at 407nm and 512nm were observed in CZS / PtTCPP, indicating the successful modification of CZS by PtTCPP.

[0040] Figure 5 Fourier transform infrared spectra of prepared CZS / PtTCPP, PtTCPP and CZS. -1 and 1724cm -1 The characteristic peaks of asymmetric vibration absorption of C-OH and C=O are lower than the characteristic peaks of FTIR spectrum of PtTCPP, which is due to the strong coordination bond between carboxyl and CZS. Fourier transform infrared (FTIR) further confirmed the successful modification of CZS by PtTCPP.

[0041] Figure 6 The photocatalytic hydrogen production performance of the prepared CZS / PtTCPP, PtTCPP, Mix-CZS-PtTCPP and CZS shows that the hydrogen production rate of CZS / PtTCPP reaches 86.7 mmol·g after PtTCPP is combined with CZS through coherent hybridization. -1 ·h -1 , which are 621.6 times and 4 times of PtTCPP and CZS respectively. However, the hydrogen evolution performance of Mix-CZS-PtTCPP, a sample physically mixed with PtTCPP and CZS, was not significantly improved compared with CZS, but decreased. These results show that the uniform dispersion and strong interaction between photosensitizer and inorganic semiconductor materials also play a vital role in improving the photocatalytic performance.

[0042] Figure 7 This is the stability diagram of the photocatalytic hydrogen production performance of the prepared CZS / PtTCPP. It can be seen from the figure that the hydrogen production performance of CZS / PtTCPP has not decreased significantly after five cycles of light hydrogen production tests. After the samples after the cycle were centrifuged and placed at room temperature for two months, the photocatalytic hydrogen production experiment of CZS / PtTCPP was repeated, and CZS / PtTCPP still has a high hydrogen production performance.

[0043] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. Porphyrin coherent hybrid bimetallic sulfide, characterized in that: Based on the coherent hybridization strategy, the porphyrin molecule is combined with the metal ion active site in the bimetallic sulfide through a coordination bond to form an inorganic-organic hybrid structure, namely the porphyrin coherent hybrid bimetallic sulfide, whose structure is:

2. The porphyrin coherent hybrid bimetallic sulfide according to claim 1, characterized in that: The porphyrin molecule is hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin; and the bimetallic sulfide is a bimetallic ZnCdS2 nanomaterial.

3. A method for synthesizing the porphyrin coherent hybrid bimetallic sulfide according to claim 1 or 2, characterized in that The specific synthesis process is: soluble zinc salt, soluble cadmium salt and soluble sulfur source are added to the hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin system through an in situ synthesis method, and an inorganic-organic hybrid structure, namely porphyrin coherent hybrid bimetallic sulfide, is synthesized based on the coherent hybridization strategy.

4. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that The specific preparation steps are: Step S1: adding 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin and an excess of metal platinum salt to a benzonitrile solvent, heating and refluxing the mixture under the protection of an inert gas until the reaction of the raw materials is complete, and subjecting the reaction solution to column chromatography separation and recrystallization purification to obtain hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin; Step S2: adding a soluble zinc salt and a soluble cadmium salt to a hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin solution, stirring the mixture at 20-40° C. for 4-8 hours, then adding a soluble sulfur source, and continuing to stir the mixture at 20-40° C. for 20-30 hours to obtain the target product, porphyrin coherent hybrid bimetallic sulfide.

5. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that The specific synthesis route of the hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin described in step S1 is:

6. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that: The metal platinum salt in step S1 is PtCl2; the molar ratio of the 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin to the metal platinum salt is 1:2-5.

7. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that: In step S2, the soluble zinc salt is Zn(NO3)2·6H2O; the soluble cadmium salt is CdCl2; the soluble sulfur source is Na2S·9H2O; the molar ratio of the soluble zinc salt, the soluble cadmium salt and the soluble sulfur source is 1:0.5~1:1.5~2.

8. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that The specific synthesis route of the porphyrin coherent hybrid bimetallic sulfide in step S2 is:

9. The method for synthesizing porphyrin coherent hybrid bimetallic sulfide according to claim 3, characterized in that: The hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin solution in step S2 is obtained by dissolving hydrophilic platinum-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin in a mixed solvent of N,N-dimethylformamide and deionized water, wherein the volume ratio of N,N-dimethylformamide to deionized water in the mixed solvent is 1:9.

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