Metal nickel complex as well as synthesis method and application thereof
By preparing a metal nickel complex as a photocatalyst, the problems of insufficient stability and working time of existing photocatalysts in water splitting and hydrogen production are solved, and efficient and stable hydrogen production is achieved.
Patent Information
- Application Number
- CN202310895250.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-20
- Publication Date
- 2025-01-21
AI Technical Summary
The existing photocatalysts have problems such as expensive, low variability, poor stability and short working time in decomposing water to produce hydrogen.
The use of a metal nickel parts as a photocatalyst, through 1,3,5-three (4-carboxyl phenyl) benzene and to be a pentramide cup [4] aromatics and nitrate nitrate in the organic solvents, have a common 轭 轭 The aroma system and molecular cage structure.
The metal nickel complex has good optical and electrical properties, stable photocatalytic activity and good charge separation efficiency, and can stably perform water decomposition to produce hydrogen for a long time, with a working time of up to 63 hours.
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Abstract
Description
Technical Field
[0001] The invention belongs to the fields of organic synthesis, nano materials and photoelectric materials, and particularly relates to a metal nickel complex and a synthesis method and application thereof. Background Art
[0002] Energy shortage and environmental pollution are two major challenges facing mankind. Hydrogen energy is an ideal clean energy source with high energy density and no pollution. Solar energy is abundant and clean, and photocatalytic water decomposition to produce hydrogen - converting solar energy into hydrogen energy - is considered to be the most ideal method to obtain hydrogen energy.
[0003] Photocatalysts are critical materials in the technology of decomposing water to produce hydrogen. Currently, photocatalysts that can be used to decompose water to produce hydrogen mainly include metals and non-metals. Metals are expensive and have little variability, while non-metals have poor stability and a relatively short working time. Summary of the invention
[0004] Based on this, the present invention provides a metal nickel complex and a synthesis method thereof, which can be used as a photocatalyst for water decomposition to produce hydrogen and has good hydrogen production performance.
[0005] The present invention includes the following technical solutions.
[0006] A method for synthesizing the metal nickel complex comprises the following steps:
[0007] Compound a, p-tert-pentylthiocalix[4]arene and nickel nitrate react in an organic solvent to obtain the metal nickel complex;
[0008] Wherein, the structural formula of the compound a is:
[0009] The structural formula of the p-tert-pentylthiocalix[4]arene is:
[0010] In some embodiments, the molar ratio of compound a, p-tert-pentylthiocalix[4]arene and nickel nitrate is 1:1.5-2.5:1.5-2.5.
[0011] In some embodiments, the molar ratio of compound a, p-tert-pentylthiocalix[4]arene and nickel nitrate is 1:2:2.
[0012] In some embodiments, the organic solvent is N,N-dimethylformamide.
[0013] In some embodiments, the reaction temperature is 150° C.-170° C., and the reaction time is 20 hours-28 hours.
[0014] In some embodiments, the reaction temperature is 160° C. and the reaction time is 24 hours.
[0015] In some embodiments, the reaction is carried out under the protection of an inert gas.
[0016] In some embodiments, the preparation method of compound a comprises the following steps:
[0017] (1) 1,3,5-tribromobenzene and (4-formylphenyl)boric acid react under the action of tetrakis(triphenylphosphine)palladium(0) and a base to obtain compound c;
[0018] (2) Compound c reacts with silver oxide in the presence of a base to obtain compound a;
[0019] The reaction formula is as follows:
[0020]
[0021] In some embodiments, the molar ratio of 1,3,5-tribromobenzene, (4-formylphenyl)boric acid, tetrakis(triphenylphosphine)palladium(0) and base in step (1) is 1:3.5-4.5:0.05-0.15:16-22.
[0022] In some embodiments, the base in step (1) is potassium carbonate.
[0023] In some embodiments, the reaction solvent of step (1) is a mixed solvent of water and tetrahydrofuran in a volume ratio of 1:8-12.
[0024] In some embodiments, the reaction temperature of step (1) is 80° C.-90° C., and the reaction time is 40 hours-56 hours.
[0025] In some embodiments, the molar ratio of compound c, silver oxide and base in step (2) is 1:20-30:35-45.
[0026] In some embodiments, the molar ratio of compound c, silver oxide and base in step (2) is 1:24-26:38-42.
[0027] In some embodiments, the base in step (2) is sodium hydroxide.
[0028] In some embodiments, the reaction solvent of step (2) is a mixed solvent of ethanol and toluene in a volume ratio of 1:4-6.
[0029] In some embodiments, the reaction temperature in step (2) is 20° C.-35° C., and the reaction time is 60 hours-80 hours.
[0030] The present invention also provides a metal nickel complex prepared by the above synthesis method.
[0031] The present invention also provides a photocatalytic material, including the following technical solution.
[0032] A photocatalytic reaction material is obtained by loading the metal nickel complex onto CdS nanorods.
[0033] In some embodiments, the mass ratio of the metal nickel complex to the CdS nanorods is 1:1-1.2.
[0034] In some of the embodiments, the method for preparing the CdS nanorods comprises the following steps: adding CdCl2·2.5H2O and thiourea to a stainless steel autoclave lined with polytetrafluoroethylene, and adding ethylenediamine; after vigorously stirring the reaction mixture for 0.8-2 hours, maintaining the autoclave at 155°C-165°C for 24 hours-48 hours to obtain the CdS nanorods.
[0035] In some of the embodiments, the molar ratio of CdCl2·2.5H2O to thiourea is 1:2-4; the ratio of CdCl2·2.5H2O to ethylenediamine is 1mmol:2mL-4mL.
[0036] The present invention also provides a method for preparing the photocatalytic material, which includes the following technical solutions.
[0037] A method for preparing the photocatalytic material comprises the following steps:
[0038] The CdS nanorods and the metal nickel complex are added into water and ultrasonicated to obtain the photocatalytic material; the concentration of the metal nickel complex in water is 0.15-0.2 mg / mL.
[0039] The present invention also provides applications of the metal nickel complex and the photocatalytic material, including the following technical solutions.
[0040] The metal nickel complex is used as a photocatalyst in decomposing water to produce hydrogen.
[0041] The photocatalytic reaction material is used in decomposing water to produce hydrogen.
[0042] The metal nickel complex of the present invention and its synthesis method and application have the following beneficial effects:
[0043] The present invention uses 1,3,5-tris(4-carboxyphenyl)benzene (compound a), tert-pentylthiocalix[4]arene (H4TBSC) and metal nickel salt as raw materials to prepare a novel metal nickel complex by a simple method. The metal nickel complex contains a conjugated aromatic system and has the structural characteristics of a molecular cage. Further research has found that the metal nickel complex has good optical and electrical properties, stable photocatalytic activity and good charge separation efficiency, can be used as a photocatalyst to photolyze water to produce hydrogen, has excellent hydrogen production performance, and has a long working time and good stability. It has important potential application value in optoelectronic materials and nanomaterials. BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Figure 1 For compound c 1 HNMR spectrum.
[0045] Figure 2 For compound a 1 HNMR spectrum.
[0046] Figure 3 This is the mass spectrum of the metal nickel complex b.
[0047] Figure 4 This is the infrared spectrum of metal nickel complex b.
[0048] Figure 5 The results of electrochemical impedance spectroscopy testing the charge recombination characteristics of metal nickel complex b.
[0049] Figure 6 The stability and charge separation efficiency of the metal nickel complex b were examined for photocurrent measurements.
[0050] Figure 7 This is the result of photocatalytic water decomposition and hydrogen production by metal nickel complex b. DETAILED DESCRIPTION
[0051] The technical scheme of the present invention is further illustrated by specific examples below. Those skilled in the art should understand that the examples are only to help understand the present invention and should not be regarded as specific limitations of the present invention.
[0052] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.
[0053] The terms "including" and "having" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.
[0054] In the present invention, the term "multiple" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.
[0055] The following are specific embodiments.
[0056] Example 1 Synthesis of Compound a
[0057]
[0058] Step 1: Synthesis of compound c
[0059] Tetrahydrofuran (250 mL), (4-formylphenyl) boronic acid (2.000 g, 13.341 mmol), tetrakis(triphenylphosphine) palladium (0) (0.342 g, 0.296 mmol) and 2M potassium carbonate (26.5 mL, 53.284 mmol) solution were added to a round-bottom flask containing 1,3,5-tribromobenzene (1.431 g, 2.960 mmol), and then heated to 85 degrees Celsius and stirred for 48 hours. After cooling to room temperature, the mixture was extracted with ethyl acetate and saturated brine. The organic layer was dehydrated with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The mixture was then purified by column chromatography using dichloromethane / n-hexane (4:1, v / v) as eluent to obtain the final product c as a white solid (yield: 1.022 g, 62%).
[0060] Spectral data: 1 H NMR(400MHz, CDCl3)δ10.10(s,3H),8.19(d,J=8.2Hz,6H),8.17(s,3H),8.05(d,J=8.2Hz,6H).MS Found:[M+H]+391.1932;'molecular formula C 27 H 18 O3'requires[M+H] + 391.1329.
[0061] Step 2: Synthesis of compound a:
[0062] Compound c (500 mg, 1.28 mmol) and Ag2O (7.42 g, 32.02 mmol) were added to a round-bottom flask, followed by a mixed solvent (toluene: ethanol = 5:1, 12 mL in total), and then an excess of sodium hydroxide (2.05 g, 51.22 mmol), followed by stirring at room temperature for 72 hours. After the reaction was completed, the reaction solution was filtered with diatomaceous earth, and hydrochloric acid was added to the filtrate to neutralize the excess sodium hydroxide. After the solvent was dried, the crude product was washed three times with n-hexane, filtered and dried to obtain 280 mg of product a (white powder), with a yield of 50%.
[0063] Spectral data: 1 H NMR(DMSO): δ(ppm)8.097(s,3H),8.065(m,12H).MS Found:[M+H]+438.20;'molecular formula C 27 H 18 O6'requires[M+H] + 438.11.
[0064] Example 2 Synthesis and Characterization of Metal Nickel Complex b
[0065] 1. Synthesis of Metal Nickel Complex B
[0066] Compound a (50.5 mg, 0.0762 mmol), tert-pentylthiocalix[4]arene (H4TBSC) (109 mg, 0.152 mmol) and Ni(NO3)2 (109 mg, 0.152 mmol) were added to a round-bottom flask, and 5 mL of dry DMF was added. Under nitrogen protection, the temperature was slowly raised to 160°C and reacted for 24 hours. After stopping the heating, the mixture was cooled to room temperature, methanol was added, and after the solid slowly precipitated, it was centrifuged to remove the liquid phase, and methanol was added for washing, centrifuged, and repeated three times. The obtained white solid was air-dried in nitrogen to obtain the metal nickel complex b with a yield of 35%.
[0067] Among them, the structural formula of H4TBSC is:
[0068] Spectral data: Found: [M-8H] 8- 1250.08; requires [M-8H] 8- 1250.18.FTIR(with KBr):v(Ni-N):624cm -1 .
[0069] 2. Study on the charge recombination characteristics, stability and charge separation efficiency of nickel complex b
[0070] Electrochemical impedance spectroscopy was used to study the charge recombination characteristics of the metal nickel complex b. Photocurrent measurement was used to detect the stability and charge separation efficiency of the metal nickel complex b.
[0071] The specific method is as follows:
[0072] Electrochemical impedance spectroscopy (EIS) and photocurrent measurements were performed using Ag / AgCl as the reference electrode, Pt wire as the counter electrode, and 0.5 M sodium sulfate (Na2SO4) solution as the electrolyte. To prepare the working electrode, 10 mg of the metal nickel complex b was dispersed in 1 mL of ethanol and 20 μL of Nafion aqueous solution (5 wt%), and then ultrasonically dispersed for 2 h. Subsequently, 0.1 mL of the slurry was dropped onto a FTO glass substrate (1 cm 2 ). After ethanol evaporation, the metal nickel complex b was still coated on the FTO glass surface. EIS was performed at room temperature with a bias potential of -700mV and an AC current amplitude of 5mV. The test frequency range was varied from 0.1Hz to 100kHz. Photocurrent measurements were generated in the frequency range of 0.1Hz to 100kHz. Illumination was provided by a 300W xenon lamp. Everything was performed at ambient temperature.
[0073] It is known that the smaller the arc radius in the Nyquist plot, the lower the charge transfer resistance, which in turn means better hydrogen production performance. Figure 5 As shown, the arc radius of the metal nickel complex b indicates that it has good carrier transfer characteristics and hydrogen production performance.
[0074] In the on / off test, the uniform and fast photocurrent response indicated their stable photocatalytic activity. The higher the photocurrent density, the higher the charge separation efficiency, which means the better performance in water splitting to produce hydrogen. Figure 6 As shown in the figure, under 6 on-off cycles under visible light irradiation, the photocurrent response of nickel complex b is clear and stable, indicating that nickel complex b has stable photocatalytic activity. At the same time, nickel complex b shows a higher photocurrent intensity during the lighting process, and decreases with a significant delay during the lighting process, which indicates that it has good charge separation efficiency and hydrogen production performance.
[0075] Example 3 Synthesis of CdS Nanorods
[0076]
[0077] CdCl2·2.5H2O (2.312 g, 10.125 mmol) and thiourea (2.312 g, 30.375 mmol) were added to a PTFE-lined stainless steel autoclave (50 mL), and 30 mL of ethylenediamine was added. After the reaction mixture was vigorously stirred for one hour, the autoclave was kept at 160°C for 24 or 48 hours. After cooling to room temperature, the yellow precipitate was filtered out and washed with distilled water and ethanol, and then dried under vacuum to obtain CdS nanorods.
[0078] Example 4 Photocatalytic decomposition of water to produce hydrogen
[0079] 1 mg of CdS nanorods and 1 mg of metal nickel complex b were added to 5 mL of water, and ultrasonicated for 5 minutes to obtain CdS nanorods loaded with complex b, which were used as photocatalytic materials; 5 mL of 0.5 M ascorbic acid aqueous solution (pH = 4) was added as a sacrificial electron donor. The flask was then sealed with a rubber septum and purged with a nitrogen / methane mixed gas (80:20 mol%) for 15 minutes. The methane present in the gas mixture was used as an internal standard for gas chromatography analysis of each experiment. The mixed solution was stirred continuously and stably, and radiated continuously from the bottom with a blue (about 470 nm) light emitting diode. The light source power was measured by light using a thermal sensor and a power meter (model: BIM-7203-0100F & BIM-7001; Hangzhou Brolight Technology Co., Ltd.) to obtain a light source power of 50 mW. The generated hydrogen was analyzed by gas chromatography (Agilent 6890 with molecular sieve A series of gas chromatography systems with a chromatographic column and a thermal conductivity detector were used to detect the production of hydrogen at different time points.
[0080] The test results are shown in Table 1 and Figure 7 As shown: the metal nickel complex b of the present invention can produce hydrogen for a long time, and the stable working time can reach 63h, which is higher than the general photocatalyst for water splitting.
[0081] Table 1 Photocatalytic hydrogen evolution results of MOC / CdS / AA under blue light irradiation
[0082]
[0083]
[0084] [a] The hydrogen conversion was calculated as the number of moles of hydrogen produced divided by twice the number of moles of complex catalyst; [b] The turnover frequency was calculated per hour; [c] The initial turnover frequency in the first five hours; [d] The photocatalytic activity of the system was defined as the number of micromoles of H2 released per milligram of CdS NR loaded per hour.
[0085] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0086] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.
Claims
1. A method for synthesizing a metal nickel complex, characterized in that: The steps include: Compound a, p-tert-pentylthiocalix[4]arene and nickel nitrate react in an organic solvent to obtain the metal nickel complex; Wherein, the structural formula of the compound a is: The structural formula of the p-tert-pentylthiocalix[4]arene is:
2. The method for synthesizing the metal nickel complex according to claim 1, characterized in that: The molar ratio of the compound a, p-tert-amylthiocalix[4]arene and nickel nitrate is 1:1.5-2.5:1.5-2.5; and / or, The organic solvent is N,N-dimethylformamide; and / or, The reaction temperature is 150°C-170°C, and the reaction time is 20 hours-28 hours; and / or, The reaction is carried out under the protection of inert gas.
3. The method for synthesizing the metal nickel complex according to claim 1 or 2, characterized in that: The preparation method of compound a comprises the following steps: (1) 1,3,5-tribromobenzene and (4-formylphenyl)boric acid react under the action of tetrakis(triphenylphosphine)palladium(0) and a base to obtain compound c; (2) Compound c reacts with silver oxide in the presence of a base to obtain compound a; The reaction formula is as follows:
4. The method for synthesizing the metal nickel complex according to claim 3, characterized in that: The molar ratio of 1,3,5-tribromobenzene, (4-formylphenyl)boric acid, tetrakis(triphenylphosphine)palladium(0) and base in step (1) is 1:3.5-4.5:0.05-0.15:16-22; and / or, The base in step (1) is potassium carbonate; and / or, The reaction solvent of step (1) is a mixed solvent of water and tetrahydrofuran in a volume ratio of 1:8-12; and / or, The reaction temperature of step (1) is 80°C-90°C, and the reaction time is 40 hours-56 hours.
5. The method for synthesizing the metal nickel complex according to claim 3, characterized in that: The molar ratio of compound c, silver oxide and base in step (2) is 1:20-30:35-45; and / or, The base in step (2) is sodium hydroxide; and / or, The reaction solvent of step (2) is a mixed solvent of ethanol and toluene in a volume ratio of 1:4-6; and / or, The reaction temperature in step (2) is 20°C-35°C, and the reaction time is 60 hours-80 hours.
6. A metal nickel complex, characterized in that The compound is prepared by the synthesis method according to any one of claims 1 to 5.
7. A photocatalytic material, characterized in that: The nickel complex is obtained by loading the metal nickel complex described in claim 6 onto CdS nanorods.
8. The photocatalytic material according to claim 7, characterized in that: The mass ratio of the metal nickel complex to the CdS nanorod is 1:1-1.
2.
9. A method for preparing the photocatalytic material according to claim 7 or 8, characterized in that: The steps include: The CdS nanorods and the metal nickel complex are added into water and ultrasonicated to obtain the photocatalytic material; the concentration of the metal nickel complex in water is 0.15-0.2 mg / mL.
10. Use of the metal nickel complex described in claim 6 as a photocatalyst or the photocatalytic material described in any one of claims 7 to 8 in decomposing water to produce hydrogen.