MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as ligand and preparation method and application of derivative thereof
阅读说明：本技术 以5-巯基-1-苯基-1h-四氮唑为配体构筑的mof材料及其衍生物制备方法和应用 (MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as ligand and preparation method and application of derivative thereof ) 是由 熊维伟 张志倩 刘周佳 郑芬芬 王敬敬 柏亿轩 张书义 章茂雄 于 2020-11-27 设计创作，主要内容包括：本发明公开了以5-巯基-1-苯基-1H-四氮唑为配体构筑的MOF材料及其衍生物制备方法和应用,该MOF材料制备为将金属盐试剂溶于去离子水中得到溶液A,5-巯基-1-苯基-1H-四氮唑配体溶于有机溶剂中得到白色溶液B,将两种溶液混合超声、加热反应后,通过离心去掉上清液,将沉淀物洗涤至中性后烘干,得到MOF材料；将MOF材料加热保温,最后得到MOF材料的衍生物。本发明制备得到一种全新的金属有机骨架材料,通过高温煅烧无需外加硫源就可获得其含氮多孔衍生碳基硫化物材料,该衍生材料可应用于电催化析氧反应,具有非常优异性能；同时本发明的制备方法简单方便,成本低,可重复性强。(The invention discloses a preparation method and application of an MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand and a derivative thereof, wherein the MOF material is prepared by dissolving a metal salt reagent in deionized water to obtain a solution A, dissolving a 5-mercapto-1-phenyl-1H-tetrazole ligand in an organic solvent to obtain a white solution B, mixing the two solutions, performing ultrasonic and heating reaction, removing a supernatant through centrifugation, washing a precipitate to be neutral, and drying to obtain the MOF material; and heating and insulating the MOF material to finally obtain the derivative of the MOF material. The invention prepares a novel metal organic framework material, and the nitrogenous porous derivative carbon-based sulfide material can be obtained by high-temperature calcination without adding a sulfur source, and the derivative material can be applied to electrocatalytic oxygen evolution reaction and has very excellent performance; meanwhile, the preparation method is simple and convenient, low in cost and strong in repeatability.)
1. A preparation method of an MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand is characterized by comprising the following steps:
dissolving a metal salt reagent in deionized water to obtain a solution A, dissolving a 5-mercapto-1-phenyl-1H-tetrazole (PMTA) ligand in an organic solvent, fully dissolving to obtain a white solution B, mixing the two solutions, and heating for reaction; and after the reaction is finished, centrifuging to remove the supernatant, washing the precipitate to be neutral, and drying to obtain the MOF material.
2. The preparation method of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand according to claim 1, wherein the MOF material synthesized in the step (1) by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand is a CoPMTA-MOF material, and the length of the MOF material is 5-50 μm; the width is 5-30 nm.
3. The preparation method of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand according to claim 1, wherein the molar ratio of the 5-mercapto-1-phenyl-1H-tetrazole (PMTA) to the metal salt reagent is 1:2-2: 1.
4. The preparation method of the MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as the ligand according to claim 1, wherein the metal salt reagent is preferably a cobalt salt, a copper salt, an iron salt or a nickel salt.
5. The method for preparing the MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as the ligand according to claim 1, wherein the organic reagent can be ethanol, acetone or N, N-Dimethylformamide (DMF).
6. The preparation method of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand according to claim 1, wherein the time for mixing and ultrasonic processing of the solution A and the solution B is 10-30 min; pouring the mixture into a reaction kettle with a polytetrafluoroethylene liner, putting the reaction kettle into an oven, and heating and reacting for 6 to 12 hours at the temperature of between 80 and 140 ℃.
7. A preparation method of derivatives of MOF materials constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as ligands is characterized by comprising the following steps:
placing the MOF material of claim 1 in a tubular furnace, introducing inert gas, calcining, and finally obtaining the nitrogen-containing porous derivative carbon-based sulfide material, namely the MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand and derivatives thereof.
8. The preparation method of the derivative of the MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as the ligand according to claim 7, wherein the calcination is carried out by heating from room temperature to 400-900 ℃ and keeping the temperature for 2-3H.
9. The preparation method of the derivative of the MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as the ligand according to claim 8, wherein the temperature rise rate is set to be 5-10 ℃/min.
10. An MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand or an application of a derivative thereof in the field of electrocatalysis.
Technical Field
The invention belongs to the technical field of electrode materials, and particularly relates to an MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand, and a preparation method and application of a derivative of the MOF material.
Background
In recent years, MOFs are used as templates or precursors to synthesize N-doped porous carbon materials, which are gaining attention in the field of energy (such as super capacitors, lithium ion batteries, fuel cells and the like). Most of organic ligands used in the traditional MOFs are aromatic carboxylate, imidazole, porphyrin macromolecules and the like, and most of selected metal ions are transition metal elements and lanthanide metals. Usually, the ligand of the MOFs can be directly used as a carbon source without additional carbon source, and the ligand containing the heteroatom (N, P, S) is an ideal precursor for synthesizing the heteroatom-doped porous carbon. Metal-organic frameworks (MOFs), as a new hybrid material built from organic ligands and metal ions (clusters), have the inherent advantages of molecular and homogeneous catalysts. Compared to conventional molecular and heterogeneous catalysts, MOFs exhibit larger specific surface area, more catalytic site number and easier structural and performance tuning, making it easier to understand reaction mechanisms and kinetics. The electronic properties of MOFs can be systematically modulated by ligand functionalization and metal ion exchange, while keeping the MOFs structure unchanged, which is advantageous for linking their structure to their electrochemical function.
MOFs, as a new starting material in the field of electrocatalysis technology, exhibit their own catalytic advantages. But also gradually show some drawbacks during the years of exploration: (1) the MOF crystal has low electron transfer efficiency and strong diffusion resistance. (2) Most MOF materials are semiconducting or non-conducting in nature. (3) MOF materials are prone to stacking, and insufficient exposure of metal sites on the surface of the bulk MOF material results in low redox reactivity. (4) Some MOFs are not stable well in strong acids and bases. In view of these various disadvantages, rational design and preparation of MOF catalysts are needed to achieve better MOF application in the field of electrocatalysis.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a preparation method of an MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand, and the MOF material prepared by the invention is a brand-new metal organic framework material and can be applied to the field of electrocatalysis.
The invention also provides a preparation method of the derivative of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand.
The invention also provides application of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand and derivatives thereof.
The technical scheme is as follows: in order to achieve the purpose, the preparation method of the MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole as a ligand comprises the following steps:
dissolving a metal salt reagent in deionized water to obtain a solution A, dissolving a 5-mercapto-1-phenyl-1H-tetrazole (PMTA) ligand in an organic solvent, fully dissolving to obtain a white solution B, mixing the two solutions, and heating for reaction; and after the reaction is finished, centrifuging to remove the supernatant, washing the precipitate to be neutral, and then putting the precipitate into a vacuum drying oven for drying to obtain the MOF material (CoPMTA-MOF material).
The synthesis method comprises the following steps of (1) synthesizing an MOF material which takes 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand, wherein the MOF material is a CoPMTA-MOF material, and the length of the MOF material is 5-50 mu m; the width is 5-30 nm.
Wherein the molar ratio of the 5-mercapto-1-phenyl-1H-tetrazole (PMTA) to the metal salt reagent is 1:2-2: 1.
Preferably, the molar ratio of 5-mercapto-1-phenyl-1H-tetrazole to metal salt reagent is 2: 1.
Wherein the metal salt reagent is cobalt salt, copper salt, iron salt or nickel salt.
Preferably, the metal salt reagent is a cobalt salt.
Wherein the organic reagent can be ethanol, acetone, or N, N-Dimethylformamide (DMF).
Wherein the time for mixing and ultrasonic processing of the solution A and the solution B is 10-30 min; pouring the mixture into a reaction kettle with a polytetrafluoroethylene liner, putting the reaction kettle into an oven, and heating and reacting for 6 to 12 hours at the temperature of between 80 and 140 ℃.
Preferably, the reaction is carried out by heating at 80 ℃, 100 ℃, 120 ℃ and 140 ℃ under different temperature conditions; most preferably, the reaction time is 12 hours at 120 ℃.
The invention relates to a preparation method of a derivative of MOF material constructed by using 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand, which comprises the following steps:
placing the MOF material in a tubular furnace, introducing inert gas as shielding gas, calcining to obtain the final product MOF material with nitrogen-containing porous derivative carbon-based sulfide material as ligand and its derivative (nitrogen-containing porous derivative carbon-based Co) using 5-mercapto-1-phenyl-1H-tetrazole (PMTA)9S8@ NC material).
Wherein the calcining is carried out by heating to 400-900 ℃ in a tubular furnace and preserving the heat for 2-3 h. Preferably, the tube furnace is set to have different required temperatures of 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃ and 900 ℃. Most preferably 700 deg.c.
Wherein the temperature rise rate of the tube furnace is set to be 5-10 ℃/min.
The invention relates to an MOF material constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand or an application of a derivative thereof in the field of electrocatalysis.
According to the invention, the 5-mercapto-1-phenyl-1H-tetrazole (PMTA) ligand contains sulfur and abundant nitrogen, a porous nitrogen-doped carbon MPMTA-MOF material can be directly synthesized, and a nitrogen-containing porous derivative carbon-based sulfide material is formed by high-temperature calcination, shows excellent oxygen evolution activity, and can provide a new material for further development and practical application in the field of electrocatalysis.
The MOF material is obtained by reacting a metal salt reagent and 5-mercapto-1-phenyl-1H-tetrazole through a solvothermal method, and is a brand new metal organic framework material. The 5-mercapto-1-phenyl-1H-tetrazole (PMTA) ligand contains sulfur and abundant nitrogen, can be directly synthesized into a porous nitrogen-doped carbon material, and forms a nitrogen-containing porous derivative carbon-based sulfide Co through high-temperature calcination without an additional sulfur source9S8@ NC material.
The MOF material is a long sheet material, the sulfide is in a porous rod shape after calcination, the activity of the porous material is increased due to the reduction of the density of the porous material, and the specific surface area of the porous material is increased due to the increase of the electrochemical activity, the catalytic effect and the like. The calcined sulfide forms a specific shape and has excellent oxygen evolution performance.
The derivative of the MOF material is a brand new metal nano material, and the obtained material can be directly used as a working electrode to be applied to electrocatalytic oxygen evolution and has excellent performance.
Has the advantages that: compared with the prior art, the invention has the following advantages:
the invention provides a brand new MOF material (CoPMTA-MOF) constructed by taking 5-mercapto-1-phenyl-1H-tetrazole (PMTA) as a ligand and a preparation method and application of a derivative thereof, the MOF material and the derivative thereof prepared by a one-step solvothermal method and high-temperature calcination are brand new metal nano materials, and the derivative material obtained by calcining the obtained MOF material can be directly used as a working electrode for electrocatalytic oxygen evolution and has excellent performance; meanwhile, the preparation method is simple and convenient, low in cost and strong in repeatability, and the preparation efficiency is greatly improved; and the simple method is suitable for the composition of different metal salts and 5-mercapto-1-phenyl-1H-tetrazole (PMTA) ligands, and can provide a prototype for the design and construction of the electrocatalytic material.
Drawings
FIG. 1 is an SEM image of a CoPMTA-MOF material prepared by the reaction of the invention at 80 ℃ for 6 h;
FIG. 2 is an SEM image of a CoPMTA-MOF material prepared by the reaction of the invention at 100 ℃ for 6 h;
FIG. 3 is an SEM image of a CoPMTA-MOF material prepared by the reaction of the invention at 100 ℃ for 12 h;
FIG. 4 is an SEM image of a CoPMTA-MOF material prepared by the reaction of the invention at 120 ℃ for 12 h;
FIG. 5 is an SEM image of a CoPMTA-MOF material prepared by the reaction of the invention at 140 ℃ for 12 h;
FIG. 6 shows the CoPMTA-MOF material derivative Co prepared by calcining at 400 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 7 shows the CoPMTA-MOF material derivative Co prepared by calcining at 500 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 8 shows the CoPMTA-MOF material derivative Co prepared by calcining at 600 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 9 shows the CoPMTA-MOF material derivative Co prepared by calcining at 700 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 10 shows the CoPMTA-MOF material derivative Co prepared by calcining at 800 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 11 shows the CoPMTA-MOF material derivative Co prepared by calcining at 900 ℃ for 2h9S8SEM picture of @ NC material;
FIG. 12 is a BET plot of a CoPMTA-MOF material prepared by the reaction of the present invention at 120 ℃ for 12 h;
FIG. 13 shows CoPMTA-MOF material derivative Co prepared by calcining at 700 ℃ for 2h9S8The BET plot for the @ NC material;
FIG. 14 shows the calcination of CoPMTA-MOF material prepared by the present invention at 400 deg.C, 500 deg.C, 600 deg.C, 700 deg.C, 800 deg.C2h to obtain a derivative Co9S8XRD patterns for @ NC material;
FIG. 15 shows the derivative Co prepared by the present invention9S8The polarization curve of the @ C material as an electrode material for the oxygen evolution reaction in an alkaline solution.
Detailed Description
The invention will be further described with reference to specific embodiments and the accompanying drawings.
The experimental methods described in the examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
Example 1
(1) Synthesizing 5-mercapto-1-phenyl-1H-tetrazole (C)7H6N4S) (PMTA) (CAS No.86-93-1) CoPMTA-MOF materials as ligands
0.435g of Co (NO) was weighed3)2·6H2Dissolving O in 12mL deionized water to obtain orange red solution A, and collecting 0.535g C7H6N4And dissolving the S in 12mL of ethanol, and fully dissolving by ultrasonic to obtain a white solution B. Mixing the two solutions, performing ultrasonic treatment for 10min, pouring the mixture into a 40mL reaction kettle with a polytetrafluoroethylene liner, putting the reaction kettle into an oven, and performing heating reaction at different temperatures; after the reaction is finished, centrifuging to remove supernatant to obtain a blue precipitate, washing the blue precipitate to be neutral by using ethanol and distilled water, and drying in a vacuum drying oven at 60 ℃ to obtain a CoPMTA-MOF material; FIGS. 1 to 5 are SEM images of the prepared CoPMTA-MOF material at different temperatures and different times (reaction at 80 ℃ for 6 h; reaction at 100 ℃ for 12 h; reaction at 120 ℃ for 12 h; and reaction at 140 ℃ for 12h), showing that the prepared material is in a long sheet shape, wherein the shape is more uniform under the condition of reaction at 120 ℃ for 12h, and the length is 5 to 50 μm; the width is 5-30 nm.
(2) Conversion of CoPMTA-MOF materials to nitrogen-containing porous derivatized carbon-based Co9S8@ NC material
And (3) putting a certain amount of the CoPMTA-MOF material obtained by reacting for 12 hours at 120 ℃ into a porcelain boat, putting the porcelain boat into the middle of a tube furnace, and introducing nitrogen as protective gas. Introducing nitrogen for 30min to purge oxygen in the tube,the temperature rise rate of the tubular furnace is set to be 5 ℃/min, the temperature is raised to different required temperatures (400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃ and 900 ℃) from room temperature, the temperature is kept for 2h, and finally the nitrogen-containing porous derivative carbon-based Co is obtained9S8@ NC material. FIGS. 6-11 show the Co derivative obtained by calcining CoPMTA-MOF material prepared by the invention for 2h at different temperatures9S8SEM image of @ NC material, it can be seen that the prepared material is curled into porous long rod shape from the previous long sheet, and the morphology of the calcined material is best maintained at 700 ℃; FIGS. 12-13 show CoPMTA-MOF materials prepared according to the invention (reaction at 120 ℃ for 12h) and derivatives Co of CoPMTA-MOF materials9S8The BET diagram of the @ NC material (calcined at 700 ℃ for 2h) shows that the specific surface area of the material is increased and the active sites are more exposed before and after calcination; FIG. 14 is an XRD pattern of a derivative obtained by calcining the prepared CoPMTA-MOF material at 400 ℃, 500 ℃, 600 ℃, 700 ℃ and 800 ℃ for 2h, and a CoPMTA-MOF material derivative Co can be seen9S8The peaks of XRD pattern of @ NC material follow standard Co9S8Peak comparison matched (PDF) at 15.5°，30.0°And 52.0°The crystal form of the obtained material is very good as shown by a sharp diffraction peak. Morphology of bulk and Co9S8In contrast, there is a rising ramp at 10 ° to 30 °, which is coated with amorphous carbon material.
Example 2
CoPMTA-MOF material derivative Co prepared by the invention9S8The @ NC material is used as an electrode material to react with oxygen evolution in an alkaline solution.
The testing steps are as follows:
the electrochemical workstations used in the electrochemical test of the invention are Chenghua CHI660E type electrochemical workstations, and are provided with rotating disc electrodes, the inner diameter of each disc electrode is 4mm, and the test is carried out at room temperature.
The three-electrode system is adopted to carry out the electrocatalytic oxygen evolution reaction test, and various CoPMTA-MOF material derivatives Co obtained in the example 1 are directly used9S8Electrochemical test is carried out by taking @ NC as a working electrode, taking a platinum wire as a counter electrode, taking an Ag/AgCl electrode as a reference electrode and taking 1mol/L KOH aqueous solution as electrolyteAnd the oxygen evolution performance of the anode is researched.
Preparation of a working electrode: first, polishing powder (Al)2O3) And (3) polishing the glassy carbon electrode smoothly, then washing with deionized water for several times, and airing at room temperature for later use. 5mg of sample (derivative Co)9S8@ NC) powder in a small glass bottle. Adding 800 mu L of deionized water and 200 mu L of ethanol, and carrying out ultrasonic treatment for 5 minutes to fully disperse the sample powder in the mixed solution. And dripping 5 mu L of mixed solution on the surface of the glassy carbon electrode, adding 5 mu L of 5 wt% Nafion solution to fix the catalyst on the surface of the electrode, and naturally drying for later use.
Preparing an electrolyte: 14.00g of KOH was weighed into a beaker, and 100mL of deionized water was added to dissolve the KOH sufficiently. Then, the solution in the beaker was transferred to a 250mL volumetric flask, and deionized water was added dropwise to the flask to prepare 250mL of a 1M KOH solution at a constant volume.
The CoPMTA-MOF material derivative Co9S8@ NC material at 10mA/cm2The overpotential required for the oxygen evolution reaction at current density was 370 mV. FIG. 15 is a polarization curve of CoPMTA-MOF material derivatives prepared by the present invention as electrode materials to oxygen evolution reaction in alkaline solution. The CoPMTA-MOF material derivative of the invention has excellent oxygen evolution performance in alkaline solution as an electrode material.
Example 3
Example 3 was prepared identically to example 1, except that: the molar ratio of the 5-mercapto-1-phenyl-1H-tetrazole (PMTA) to the metal salt reagent is 1:2, the metal salt reagent is copper nitrate, the organic reagent is acetone, the mixing and ultrasonic time of the solution A and the solution B is 30min, and the heating rate of the tube furnace is set to be 10 ℃/min.
Example 4
Example 4 was prepared identically to example 1, except that: the molar ratio of the 5-mercapto-1-phenyl-1H-tetrazole (PMTA) to the metal salt reagent is 1:1, the metal salt reagent is ferric nitrate, and the organic reagent is DMF.