CN114875446A - Ni-doped MIL-88A @ CoMo 8 Preparation method and application of composite material - Google Patents

Ni-doped MIL-88A @ CoMo 8 Preparation method and application of composite material Download PDF

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CN114875446A
CN114875446A CN202210392302.2A CN202210392302A CN114875446A CN 114875446 A CN114875446 A CN 114875446A CN 202210392302 A CN202210392302 A CN 202210392302A CN 114875446 A CN114875446 A CN 114875446A
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郭伟艺
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Abstract

The invention discloses Ni-doped MIL-88A @ CoMo 8 The preparation method and the application of the composite material comprise the following steps: (1) dissolving 1.2mmol of fumaric acid in 25ml of deionized water, and stirring at 4000rpm at 70 ℃ for 10min to obtain a solution A; (2) 1.3mmol of FeCl 3 ·9H 2 O and 3.9mmol Ni (NO) 3 ) 2 ·6H 2 O, 0.1 or 0.2 or 0.3mmol CoMo 8 Dissolving in 5ml of deionized water, and stirring at 4000rpm for 10min at normal temperature to obtain a solution B; (3) adding the solution B into the solution A and stirring for 10 min; (4) transferring the mixed solution in the step (3) into a stainless steel autoclave with a polytetrafluoroethylene lining, and keeping the mixed solution at 120 ℃ for 6 hours; cooling to room temperature, and separatingSeparating the core, washing with deionized water and ethanol, and drying in a vacuum drying oven to obtain Ni-MIL-88A @ CoMo 8 A composite material. The invention selects Fe-MOF and cobalt molybdenum polyacid for compounding, and simultaneously carries out nickel doping on the Fe-MOF and the cobalt molybdenum polyacid, thereby being simple and easy to obtain, having low cost, high-efficiency electro-catalytic hydrogen evolution performance and good stability.

Description

Ni-doped MIL-88A @ CoMo 8 Preparation method and application of composite material
Technical Field
The invention belongs to the technical field of catalyst preparation, and particularly relates to Ni-doped MIL-88A @ CoMo 8 Preparation method of composite material, and Ni-doped MIL-88A @ CoMo prepared by preparation method 8 The application of the composite material in electrocatalytic hydrogen evolution.
Background
Energy crisis and environmental issues have become two major challenges facing humans, electrochemical conversion and storage being the most promising means of energy storage, and more research is being devoted to the development of advanced and efficient energy conversion and storage. The search for an electrocatalyst with small overpotential, good stability and fast reaction rate is a related subject of current research. In the electrocatalytic decomposition of water, both hydrogen evolution and oxygen evolution, a high-efficiency catalyst is needed to reduce the reaction energy barrier and improve the utilization efficiency of electric energy. Noble metal materials are recognized as the most advanced active hydrogen and oxygen evolution catalysts, but their reserves are limited and expensive, limiting their large-scale industrial application. Therefore, the development of cheap and efficient non-noble metal catalysts is of great significance.
Disclosure of Invention
In order to solve the technical problems, the invention aims to provide a Ni-doped MIL-88A @ CoMo 8 Preparation method and application of composite material, selecting Fe-MOF (MIL-88A) and cobalt molybdenum polyacid (CoMo) 8 ) The composite material is compounded, and simultaneously, the nickel is doped, so that the composite material is simple and easy to obtain, has low cost, and has high-efficiency electrocatalytic hydrogen evolution performance and good stability.
In order to further achieve the purpose, the invention adopts the following technical scheme: ni-doped MIL-88A @ CoMo 8 The preparation method of the composite material comprises the following steps:
(1) dissolving 1.2mmol fumaric acid in 25ml Deionized (DI) water and stirring at 4000rpm for 10min at 70 deg.C to give solution A;
(2) 1.3mmol of FeCI 3 ·9H 2 0 and 3.9mmol Ni (N0) 3 ) 2 ·6H 2 O, 0.1 or 0.2 or 0.3mmol CoMo 8 Dissolving in 5ml of deionized water, and stirring at 4000rpm for 10min at normal temperature to obtain a solution B;
(3) adding the solution B into the solution A and stirring for 10 min;
(4) transferring the solution in the step (3) into a polytetrafluoroethylene-lined stainless steel autoclave (the total volume is 50ml), and keeping the solution at 120 ℃ for 6 h;
cooling to room temperature, centrifuging, washing with deionized water and ethanol, and drying in a vacuum drying oven to obtain Ni-MIL-88A @ CoMo 8 A composite material.
Correspondingly, the invention also claims Ni-MIL-88A @ CoMo prepared by the preparation method 8 When the composite material is applied to electrocatalytic hydrogen evolution, and the polyacid composite content is 0.2mmol, the hydrogen evolution catalytic performance of the NFC-2 composite catalyst is the most excellent. At a current density of 10mA cm -2 When the voltage is high, the overpotential of NFC-2 is 161mV, and the Tafel slope is 95.02mV dec -1 The resistance was 20.04 Ω.
Compared with the prior art, the invention has the characteristics and beneficial effects that:
(1) polyacid compounding and nickel doping play different roles in the process of improving the catalytic performance of the MIL-88A, and the polyacid is used as a material with excellent conductivity, so that the charge transfer capability in the hydrogen evolution process of the MIL-88A is effectively enhanced, and the resistance between the surface of the catalyst and the electrolyte is reduced. The nickel doping can effectively accelerate the kinetic process of the hydrogen evolution reaction, thereby accelerating the hydrogen evolution reaction. In addition, the surface modification effect of the doped nickel and the polyacid also increases the number of active sites of MIL-88A, and provides more reaction sites for the Heyrovsky process.
(2) Ni-MIL-88A @ POM (Ni-MIL-88A @ CoMo) constructed by the invention 8 ) In the composite material, CoMo 8 Are fixed as inorganic building blocks, providing more redox reaction sites. The uniform structure of Ni-MIL-88A ensures uniform distribution of active sites throughout the catalyst to combine the advantages of POM and MOF, maintaining Ni-MIL-88A @ CoMo 8 Stability in electrolyte.
Drawings
FIG. 1 is MIL-88A, Ni-MIL-88A, MIL-88A @ CoMo 8 (ii) an XRD pattern, (b) an FTIR pattern of NFC-x;
FIG. 2 is MIL-88A, Ni-MIL-88A, MIL-88A @ CoMo 8 Scans of NFC-x (a-g);
FIG. 3 is the elemental distribution and EDS atomic ratio of Fe, C, O, Mo and P;
FIG. 4 is 20% Pt/C, MIL-88A, Ni-MIL-88A, MIL-88A @ CoMo 8 Electrochemical performance of NFC-x in alkaline electrolyte (a) polarization curves for different samples at scan rate 3 mV/s; (b) the corresponding Taffel slope; (c) comparing the polarization curve of the corresponding sample with the Taffel slope; (d) a corresponding Nyquist diagram;
FIG. 5 is (a) MIL-88A; (b) CV curves of NFC-2 under different scanning rates, wherein the scanning rates are respectively 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 mV/s; (c) cdl value of MIL-88A, NFC-2; (d) comparison of polarization curves before and after 2000 cycles of catalyst NFC-2 (10 mAcm is inset) -2 Current-time stability test for 24h below).
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides Ni-doped MIL-88A @ CoMo 8 The preparation method of the composite material comprises the following steps:
(1) 1.2mmol of fumaric acid was dissolved in 25ml of Deionized (DI) water and stirred at 4000rpm for 10min at 70 ℃ to give solution A.
(2) 1.3mmol of FeCl 3 ·9H 2 0 and 3.9mmol Ni (NO) 3 ) 2 ·6H 2 O, 0.1 or 0.2 or 0.3mmol CoMo 8 Dissolved in 5ml of deionized water and stirred at 4000rpm for 10min at normal temperature to give solution B.
(3) Add solution B to solution a and stir for another 10 min.
(4) The solution was transferred to a stainless steel autoclave lined with polytetrafluoroethylene (total capacity 50ml) and kept at 120 ℃ for 6 h; after cooling to room temperature, Ni-MIL-88A @ CoMo is obtained by centrifugal separation 8 Composite materialThe material is washed by deionized water and ethanol and finally dried in a vacuum drying oven.
In the invention, the concentrations of the polyacid in the compound are respectively changed to be 0.1, 0.2 and 0.3mmol, samples with different polyacid compound quantities are respectively expressed as NFC-1, NFC-2 and NFC-3, and the samples can also be abbreviated as NFC-x.
No additional CoMo was added to solution B 8 Synthesizing Ni-MIL-88A by the same preparation method as the sample; no additional Ni (NO) was added to solution B 3 ) 2 ·6H 2 O, Synthesis of MIL-88A @ CoMo Using the same method as the above sample 8 (ii) a Retaining only FeCl in solution B 3 ·9H 2 And O, repeating the synthesis method to obtain a sample MIL-88A.
As shown in FIG. 1(a-b), each is CoMo 8 、MIL-88A、Ni-MIL-88A、MIL-88A@CoMo 8 And X-ray diffraction patterns and infrared patterns of NFC-1, NFC-2 and NFC-3. Analyzing the phase structure of the sample by XRD to obtain CoMo 8 And MIL-88A (Fe) samples were all as described in (R.Z Chohan, A Rauf. Antimicrobial cobalt (II), Nickel (II) and Zinc (II) Complexes of noncogenic Acid-derived Schiff-bases [ J].Journal of Enzyme Inhibition and Medicinal Chemistry.2002.(17)：101-106；②Liu Y，Huang Y.Preparation of Magnetic Fe 3 O 4 /MIL-88A Nanocomposite and Its Adsorption Properties for Bromophenol Blue Dye in Aqueous Solution[J]Nanomaterials (Basel, Switzerland) 2019; 9(1)), and no diffraction peak except for MIL-88A appears, indicating that the synthesized sample is pure-phase MIL-88A (Fe). Characteristic peaks at 10.2 ° and 14.8 ° correspond to the (101) and (002) crystal planes, respectively. Compared with pure MIL-88A, no impurity phase appears in the Ni-MIL-88A, which shows that kneading doping has no influence on the formation of MIL-88A. In addition, the XRD pattern of the sample was not significantly changed, which also indicates that nickel is not present as a compound, but rather is incorporated into the crystal lattice of MIL-88A by doping. Although it is reported in the literature that the diffraction peak corresponding to a certain crystal plane shifts after doping with an element, the phenomenon is not observed in the experimentProbably because the doping amount of nickel is relatively less, the influence on the MIL-88A crystal lattice is less. The nickel doping process does not change much the crystal structure and composition of MIL-88A. But the growth rate and direction are changed, most of the peaks disappear, and only the weaker (101) and (002) crystal planes are reserved. After being compounded with the polyacid, the composite material shows the peak specific to the polyacid, and meanwhile, the characteristic peak of MIL-88A is kept at 10.2 degrees and 14.8 degrees. The structural properties of MIL-88A were not altered during the complexation with polyacids, where MIL-88A is a three-dimensional flexible framework based on fumarate diionically linked iron (III) trimers with interconnected pores and open channels along the c-axis. The polyacid anionic groups are thus dispersed at the molecular level. In order to verify that the synthesized compound contains an organic ligand and a polyacid salt, infrared spectroscopy was performed on the synthesized compound. At a wavelength of 3400-3600cm -1 A distinct characteristic peak is observed in the broader absorption band, which is 0-H stretching vibration on the catalyst surface and the surface adsorbed water, at 1395cm -1 And 1596Gm -1 The peak at (a) is the symmetric and asymmetric oscillation of the carboxyl group. At a wavelength of 700-900cm -1 Within the range, characteristic peaks of broad and short polyacid anions are clearly observed, and the synthesis of polyacid raw materials can be determined. At a wavelength of 575cm -1 A distinct characteristic peak was observed at the location, reflecting the vibration of the Fe-O bond in MIL-88A. After Ni doping, the characteristic peak of Ni-MIL-88A has no obvious change, which shows that the Ni doping makes the MIL-88A composition unchanged. In the composite samples MIL-88A @ CoMo8 and NFC-x, the position of the main peak is not obviously changed after the cobalt molybdic acid is modified, which indicates that the structure of the modified MIL-88A is not damaged. Also visible are the wavelengths 1055, 960, 776 and 860cm -1 4 slight bands appear at the center, which belong to Mo ═ O t 、Co-O c 、Mo-O e -Mo and Mo-O b Tensile vibration of-Mo, indicating that CoMo is confirmed 8 Modification of polyoxoanions on the surface of MIL-88A (Fe).
To study MIL-88A, MIL-88A @ CoMo 8 Ni-MIL-88A and NFC-x catalyst, and Scanning Electron Microscope (SEM) testing was performed on the samples. The results are shown in FIG. 2. FIGS. 2(a-b) are each pure polyacid (CoMo) 8 ) And pureSEM image of MIL-88A. As can be observed from the figure, CoMo 8 Consists of relatively uniform spheres, while MIL-88A consists of particles with well-defined central prismatic portions and pyramidal ends, with smooth surfaces. The morphology of the submicron elongated rod crystals presented, and the thermal synthesis of the synthesis of MOF nanoparticles MIL-88A with different solvents (Chalati, T, Horcajada, P. optimization of the synthesis of MOF nanoparticles of the submicron rod crystals J-88A]MIL-88A prepared from j.mater.chem.2011, 21, 2220-. The particle size is between about 1.5-3 μm long and 300-450nm wide. Ni-MIL-88A and MIL-88A @ CoMo obtained by doping and surface modification 8 As shown in FIGS. 2(c) and (d), the major axis structure of the MIL-88A micro rod is maintained. After nickel doping, the average length of these hexagonal nanorods decreased from 2 μm to 1.2 μm, while the average width increased from 375nm to 550 nm. And MIL-88A @ CoMo obtained by surface modification 8 It can be observed from the figure that the average length of these hexagonal nanorods also increased from 2 μm to 3.5 μm and the average width increased from 375nm to 480nm after the polyacid was complexed. Meanwhile, irregular particles exist on the surface, more active sites are exposed to a certain degree, and the change of the shape and the particle size after the polyacid is compounded is very likely to improve the hydrogen evolution catalytic performance of the composite catalyst. FIG. 2(e-g) is an SEM image of NFC-1, NFC-2, NFC-3, with CoMo 8 The composite content of (a) is increased, and the irregular particles on the surface of the composite material are gradually converted into rod-shaped particles with the length of about 50 nm. When CoMo 8 When the content of (b) was increased to 0.3mmol, the micro-rod structure disappeared, followed by the appearance of a larger spherical structure having a diameter of about 1 μm. This is probably due to the fact that CoMo 8 Too much, which renders the solution acidic and destroys the formation of MIL-88A crystals. SEM results show that the composite polyacid can increase the active sites of MIL-88A, and meanwhile, the doped particles of nickel are used for MIL-88A and MIL-88A @ CoMo 8 The appearance of the alloy has no obvious influence.
To further characterize the distribution of elements within the test area of the sample, an Energy Distribution Spectrum (EDS) test was performed, with the results shown in fig. 3. Purple, red, green, blue, yellow correspond to five elements of Fe, C, Ni, Co, Mo, respectively, and uniform distribution of the five elements can be clearly observed in the test area, indicating the presence of the five elements in the synthesized sample. The uniform distribution of nickel preliminarily confirms the successful doping of the nickel element.
Samples such as NFC-2 were subjected to LSV testing in 1M KOH solution: respectively using a sample electrode, a carbon rod electrode and saturated calomel (Hg/Hg2 Cl) 2 ) The electrode is used as a working electrode, a counter electrode and a reference electrode, the scanning potential range is-0.9-1.5V, and the scanning speed is 0.003V/s. Respectively prepare MIL-88A, Ni-MIL-88A, MIL-88A @ CoMo 8 NFC-x (x ═ 1, 2, 3), and a blank carbon cloth and a 20% Pt/C electrode were compared, and the measured hydrogen evolution polarization curves are shown in fig. 4 (a). In order to obtain the real hydrogen evolution catalytic performance in the three-electrode system, all polarization curves are not corrected by iR.
The overpotentials for all samples are listed in FIG. 4 (c). When the current density is 10mA cm -2 In the mean time, the pure sample MIL-88A has the worst hydrogen evolution performance, the overpotential is 318mV, and Ni and CoMo are doped 8 Thereafter, the overpotential for MIL-88A was reduced to 286mV and 228mV, indicating that the Ni-doped or CoMo 8 The composition has a certain promotion effect on the hydrogen evolution catalytic performance of MIL-88A, wherein the CoMo is compounded 8 The promotion effect on the catalytic performance is more obvious. Based on the results, the composite catalysts of NFC-1, NFC-2 and NFC-3 are synthesized, the results show that under the synergistic action of nickel and polyacid, the hydrogen evolution catalytic performance is improved very obviously, when the polyacid composite content is 0.2mmol (NFC-2), the optimal hydrogen evolution catalytic performance is obtained, the overpotential of the composite catalysts is 161mV, and the overpotentials of NFC-1 and NFC-3 are 185mV and 267mV respectively. By comparison, MIL-88A @ CoMo 8 The hydrogen evolution performance of the composite polyacid is even better than that of NFC-3, because the composite polyacid is too much in use, the structure of MIL-88A is damaged, meanwhile, the particle size of the composite is increased, the specific surface area of the catalyst is reduced, the catalytic active sites are reduced, and the occurrence of hydrogen evolution reaction is not facilitated. These results all show that doping Ni or composite polyacid has an improvement effect on the hydrogen evolution catalytic performance of MIL-88A, but the improvement effect is limited when the Ni or the composite polyacid is used alone. And the unique hexagonal rod-shaped structure of MIL-88A also plays a role in improving the hydrogen evolution catalytic performance. Under the combined action of the threeAnd the NFC-2 obtains the most excellent hydrogen evolution catalytic performance.
To study the hydrogen evolution reaction kinetics, we passed the polarization curve in fig. 4(a) through the Tafel formula: η ═ a + blogj translates to the Tafel slope plot of fig. 4 (b). Where b is the Tafel slope, a is the Tafel constant, and j is the current density. The reaction mechanism in the HER evolution process can be judged by fitting calculation of tafel slopes to the prepared materials. As shown in FIG. 3(c), pure MIL-88A exhibited the highest Tafel slope (151.96mV dec) -1 ). When doped with Ni, the Tafel slope of Ni-MIL-88A decreases to 120.58mV dec -1 MIL-88A @ CoMo after complexing the polyacid 8 The Tafel slope of the sample is reduced to 137.80mV dec -1 . Wherein the Tafel slope ratio of Ni-MIL-88A to MIL-88A @ CoMo 8 And the lower value indicates that the action of doping Ni is more obvious than that of the composite polyacid in the process of accelerating the hydrogen evolution reaction kinetics, and the composite polyacid can enhance the hydrogen evolution catalytic capability by improving the hydrogen evolution kinetics process of MIL-88A. Therefore, under the synergistic effect of Ni doping and polyacid recombination, the NFC-1, NFC-2 and NFC-3 composite catalysts have a faster hydrogen evolution reaction kinetic process. The Tafel slopes are 100.78mV dec respectively -1 ，95.02mV dec -1 And 135.22mV dec -1 This shows that the hydrogen evolution catalytic performance of the composite polyacid with proper content on Ni-MIL-88A is greatly improved. The Tafel slope may also reflect the hydrogen evolution catalysis mechanism of the catalyst. When Taffel slope b is 120mV dec -1 The electrochemical desorption step and the composite desorption step have little influence on the rate of the hydrogen evolution reaction. According to the experiment, the Tafel slope value of the NFC-2 is 95.02mV dec -1 This indicates that the hydrogen evolution reaction mechanism is the Volmer-Heyrovsky mechanism, wherein the Heyrovsky reaction is the rate-limiting step. The method has very important significance for optimizing the hydrogen evolution dynamic process of the catalyst and improving the catalytic performance of hydrogen evolution.
EIS spectra of all samples are shown in FIG. 4 (d). According to the resistance value of the catalyst obtained by the equivalent circuit, the resistance value is consistent with the LSV curve and Tafel slope results, in all the tested samples, the Rct value of the pure sample MIL-88A is the highest (1375 omega), and the higher Rct value reflects that the electron transfer of the MIL-88A in the hydrogen evolution process is difficult, so the analysis is difficultThe hydrogen proceeds slowly. Ni doping and composite polyacid have certain promotion effect on reduction of resistance, but different from the Tafel slope result, the composite polyacid plays a more obvious effect on reduction of Rct than doping Ni, and the effect is expressed as MIL-88A @ CoMo 8 The charge transfer resistance of (2) was 435.8. omega. and that of Ni-MIL-88A was 750.6. omega. This is because the polyacid has excellent electron transfer properties, and the electron of the electrocatalyst compounded with the polyacid can realize faster charge transfer depending on the electron transfer properties of the polyacid during the hydrogen evolution process, thus showing lower charge transfer resistance. Under the synergistic effect of the polyacid and the Ni, the resistance values of the NFC-1, the NFC-2 and the NFC-3 are respectively reduced to 47.96 omega, 20.04 omega and 63.84 omega, and the charge transfer resistance of the composite material is greatly improved compared with that of the pure MIL-88A. By combining the experimental results, in the NFC-2 composite catalyst, the polyacid can enhance the conductivity and reduce the charge transfer resistance, and meanwhile, the polyacid recombination can also increase the specific surface area of MIL-88A and realize the enhancement of the activity of the catalyst by combining the analysis of the scanning result.
FIGS. 5(a) and (b) show the sweep rates in the region of 10, 20, 30, 40, 50, 60, 70, 80, 90, 100mV s -1 The following CV graphs of pure MIL-88A and NFC-2 were fitted to obtain the electric double layer capacitance, as shown in fig. 5 (c). The Cdl of MIL-88A was 2.55mF cm -2 The Cdl of the NFC-2 composite catalyst is 3.51mF cm -2 Cs of all materials herein is 40. mu.F cm according to the formula ESCA ═ Cdl/Cs for the calculation of electrochemically active surface area -2 . As can be seen, the ECSA of MIL-88A and NFC-2 are 63.75 and 87.75. Compared with pure MIL-88A, the number of active sites of NFC-2 is obviously increased. This shows that not only can the hydrogen evolution kinetics process be promoted, agglomeration be reduced and the charge transfer resistance be reduced by Ni doping and polyacid recombination, but also new active sites can be generated by MIL-88A, and the Heyrovsky process can be accelerated.
As shown in FIG. 5(d), the current density was 10mA cm in the 1M KOH electrolyte -2 The CV cycle of 2000 cycles is carried out, and after 2000 cycles, the overpotential of the NFC-2 is found to be increased to 168mV from the original 161mV, changed by 7mV and attenuated by 4%. The electrode material NFC-2 was subsequently subjected to a current density of 10mA cm -2 While at the same timeThe stability test (shown in the inset of fig. 5 (d)) for 12h, it can be observed that the current of the catalyst remains stable as a whole without significant fluctuation, indicating that NFC-2 has good stability. This indicates that the NFC-2 composite catalyst has better cycle stability. The reason for the increase in overpotential may be that the composite polyacid is partially dissolved in the alkaline electrolyte during the long-term stability test, so that the number of active sites is reduced, thereby causing the degradation of catalytic performance.
In conclusion, under the synergistic effect of nickel doping and polyacid compounding, the hydrogen evolution catalytic performance of the MIL-88A is effectively improved. When the polyacid compound content is 0.2mmol, the hydrogen evolution catalytic performance of the NFC-2 compound catalyst is the most excellent. At a current density of 10mA cm- 2 When the voltage is high, the overpotential of NFC-2 is 161mV, and the Tafel slope is 95.02mV dec -1 The resistance was 20.04 Ω.
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (3)

  1. Ni-doped MIL-88A @ CoMo 8 The preparation method of the composite material is characterized by comprising the following steps:
    (1) dissolving 1.2mmol of fumaric acid in 25ml of deionized water, and stirring at 4000rpm at 70 ℃ for 10min to obtain a solution A;
    (2) 1.3mmol of FeCl 3 ·9H 2 O and 3.9mmol Ni (NO) 3 ) 2 ·6H 2 O, 0.1 or 0.2 or 0.3mmol CoMo 8 Dissolving in 5ml of deionized water, and stirring at 4000rpm for 10min at normal temperature to obtain a solution B;
    (3) adding the solution B into the solution A and stirring for 10 min;
    (4) transferring the mixed solution in the step (3) into a stainless steel autoclave with a polytetrafluoroethylene lining, and keeping the mixed solution at 120 ℃ for 6 hours;
    cooling to room temperature, centrifuging, and removingWashing with water and ethanol, and drying in a vacuum drying oven to obtain Ni-MIL-88A @ CoMo 8 A composite material.
  2. 2. Ni-MIL-88A @ CoMo prepared by the preparation method of claim 1 8 The application of the composite material in electrocatalytic hydrogen evolution.
  3. 3. The use as claimed in claim 2, wherein the NFC-2 composite catalyst has the most excellent hydrogen evolution catalytic performance at a current density of 10ma cm, when the polyacid complex content is 0.2mmol -2 When the voltage is high, the overpotential of NFC-2 is 161mV, and the Tafel slope is 95.02mV dec -1 The resistance was 20.04 Ω.
CN202210392302.2A 2022-04-14 2022-04-14 Ni-doped MIL-88A @ CoMo 8 Preparation method and application of composite material Pending CN114875446A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101869851A (en) * 2010-05-14 2010-10-27 东北师范大学 Supported polyoxometallate crystalline catalyst and preparation method thereof
CN110026241A (en) * 2019-04-25 2019-07-19 哈尔滨理工大学 A kind of three-dimensional polyacid base nickel metal-organic crystalline catalysis material and preparation method thereof
CN110433860A (en) * 2019-07-11 2019-11-12 哈尔滨理工大学 A kind of three-dimensional non-through phosphomolybdic acid base copper crystalline catalysis material and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101869851A (en) * 2010-05-14 2010-10-27 东北师范大学 Supported polyoxometallate crystalline catalyst and preparation method thereof
CN110026241A (en) * 2019-04-25 2019-07-19 哈尔滨理工大学 A kind of three-dimensional polyacid base nickel metal-organic crystalline catalysis material and preparation method thereof
CN110433860A (en) * 2019-07-11 2019-11-12 哈尔滨理工大学 A kind of three-dimensional non-through phosphomolybdic acid base copper crystalline catalysis material and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Z. H. WANG: "Polyoxometalate/metal-organic framework hybrids and their derivatives for hydrogen and oxygen evolution electrocatalysis", vol. 19, pages 100618 *
葛靖暄;胡钧;朱盈婷;泽妮诗;臧德进;秦召贤;黄毅超;张江威;魏永革;: "多酸在电催化析氢反应中的应用研究进展", 物理化学学报, no. 01, pages 83 - 102 *

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