阅读说明：本技术 用于电化学析氢的偶联开笼c60及二硫化钼复合材料和其制备方法 (Coupled cage C60 for electrochemical hydrogen evolution, molybdenum disulfide composite material and preparation method thereof ) 是由 李青 苏玉金 杨静 陈立芳 李泽 乔山林 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种用于电化学析氢的偶联开笼C60及二硫化钼复合材料和其制备方法,该材料以偶联开笼C60为刚性骨架,表面掺杂二硫化钼。其制备方法是先依次制备开笼C60及偶联开笼C60,然后将偶联开笼C60与四水合钼酸铵、硫脲水溶液进行水热合成反应,即得P-PC60@MoS-(2),实现对二硫化钼的改性。本发明制得的新型复合材料作催化剂用于电化学析氢,具有良好的电催化性能。(The invention discloses a coupled open cage C60 for electrochemical hydrogen evolution, a molybdenum disulfide composite material and a preparation method thereof, wherein the material takes a coupled open cage C60 as a rigid framework, and molybdenum disulfide is doped on the surface of the material. The preparation method comprises the steps of sequentially preparing the cage opening C60 and the coupling cage opening C60, and then carrying out hydro-thermal synthesis reaction on the coupling cage opening C60, ammonium molybdate tetrahydrate and thiourea aqueous solution to obtain P-PC60@ MoS 2 And the modification of the molybdenum disulfide is realized. The novel composite material prepared by the invention is used as a catalyst for electrochemical hydrogen evolution and has good electrocatalytic performance.)

1. A coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution is characterized in that the material takes a coupled open cage C60 as a rigid framework, and molybdenum disulfide is doped on the surface of the material.

2. A preparation method of a coupled cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution is characterized by comprising the following steps of:

s1 preparation of Kai-cage C60

C60 and 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine are dissolved in o-dichlorobenzene, heated and refluxed, cooled and chromatographed, and reactants are removed to obtain a product A;

dissolving the product A in carbon tetrachloride, and reacting in an oxygen atmosphere to obtain an open cage C60;

s2 preparation of coupled open cage C60

Taking the coupling cage C60, dimethanol formal, anhydrous ferric trichloride and 1, 2-dichloroethane, and sequentially carrying out low-temperature heating reaction, high-temperature heating reaction, Soxhlet extraction and vacuum drying to obtain the coupling cage C60;

S3. [email protected]₂preparation of

Dissolving ammonium molybdate tetrahydrate and thiourea in water, uniformly mixing to obtain a solution B, carrying out hydrothermal synthesis reaction on the solution B and a coupling cage C60, and cooling to obtain [email protected] MoS₂Namely a coupling cage-opening C60 for electrochemical hydrogen evolution of a target product and a molybdenum disulfide composite material.

3. The method as claimed in claim 2, wherein the heating and refluxing step S1 is carried out by heating to 170-185 ℃ for 20-25 h.

4. The method for preparing the coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 2 or 3, wherein in step S1, the cooling chromatography adopts silica gel column chromatography.

5. The method for preparing coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 4, wherein in step S1, said cooling is performedThe eluent for the chromatography is CS₂Or/and ethyl acetate.

6. The method for preparing the coupled cage-opened C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 2 or 3, wherein in step S1, the mass ratio of C60, 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine and o-dichlorobenzene is 3: 2: 36-42;

the mass ratio of the product A to carbon tetrachloride is 1: 17-23.

7. The method for preparing the coupled cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 2 or 3, wherein in step S2, the mass-to-volume ratio of the cage C60, dimethanol formal, anhydrous ferric trichloride and 1, 2-dichloroethane is 25g:4-8g:10-13g: 30L.

8. The method for preparing the coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 2 or 3, wherein in step S2,

the low-temperature heating reaction is carried out at 42-48 ℃ for 4-6h under an anaerobic condition;

the high-temperature heating reaction condition is that the heating is carried out for 4-6h at the temperature of 110-130 ℃ under the anaerobic condition;

the solvent for the soxhlet extraction is methanol.

9. The method for preparing the coupled cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to claim 2 or 3,

the mass volume ratio of the ammonium molybdate tetrahydrate to the thiourea to the water is 20-23g:70-78g: 1L;

the mass of the molybdenum disulfide is integral multiple of that of the coupling cage C60, and the molybdenum disulfide is generated by the reaction of ammonium molybdate tetrahydrate and thiourea.

10. The method for preparing the coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution according to any one of claims 2, 3 or 4, wherein in step S3, the hydrothermal synthesis reaction is performed under the conditions of heating to 190 ℃ and 210 ℃ for 17-19h, and the cooling is performed under the temperature reduced to 20-25 ℃.

Technical Field

The invention belongs to the technical field of electrochemical materials, and relates to a preparation method of a coupled open-cage C60 composite material, in particular to a coupled open-cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution and a preparation method thereof.

Background

Under the influence of global energy crisis, the vigorous development of renewable energy has become a consensus of people. Hydrogen energy is a renewable clean energy source, and compared with the traditional fossil fuel, the hydrogen energy has the advantages of high energy density, environmental friendliness and the like. The development and utilization of hydrogen energy cannot be realized without a catalytic hydrogen evolution material, and platinum group metals as common catalytic hydrogen evolution materials play an important role in hydrogen energy utilization, but the metal mineral resources are scarce and the price is high, so that the platinum group metals cannot be widely applied to actual production. Therefore, researchers have been working on developing non-noble metal materials as possible alternatives to new electrocatalysts in an effort to fully utilize the high density clean energy source, hydrogen energy, to provide a viable alternative to non-renewable fossil fuels.

Molybdenum disulfide is a layered material, the edge of the molybdenum disulfide has more active sites and is an ideal material for electrocatalytic hydrogen evolution, but molybdenum disulfide has a wider band gap and poorer conductivity and is easy to accumulate and agglomerate, and the defects seriously influence the development of molybdenum disulfide in the field of electrocatalytic hydrogen evolution. Therefore, the key problem to be solved is to prepare the doped composite material by modifying the molybdenum disulfide material, improve the band gap and the conductivity of the molybdenum disulfide and improve the electrocatalytic hydrogen evolution performance of the molybdenum disulfide.

Disclosure of Invention

Another object of the present invention is to provide a coupled open cage C60 and molybdenum disulfide composite for electrochemical hydrogen evolution;

the invention also aims to provide a preparation method of the composite material, which is prepared by coupling the open cage C60 as a rigid framework and doping molybdenum disulfide on the surface, so as to achieve the purpose of obtaining the novel composite material for electrochemical hydrogen evolution by modifying the molybdenum disulfide.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a coupled open cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution are disclosed, which uses coupled open cage C60 as rigid skeleton and molybdenum disulfide is doped on the surface.

The invention also provides a preparation method of the coupled cage-opening C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution, which comprises the following steps in sequence:

s1, preparation of cage opening C60

C60 and 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine are dissolved in o-dichlorobenzene, heated and refluxed, cooled and chromatographed, and reactants are removed to obtain a product A;

dissolving the product A in carbon tetrachloride, and reacting in an oxygen atmosphere to obtain an open cage C60;

s2, preparation of coupled cage C60

Taking the coupling cage C60, dimethanol formal, anhydrous ferric trichloride and 1, 2-dichloroethane, carrying out low-temperature heating reaction and high-temperature heating reaction, Soxhlet extraction, and vacuum drying to obtain the coupling cage C60;

[email protected]₂preparation of

Dissolving ammonium molybdate tetrahydrate and thiourea in water, uniformly mixing to obtain a solution B, carrying out hydrothermal synthesis reaction on the solution B and a coupling cage C60, and cooling to obtain [email protected] MoS₂。

As a limitation of the present invention, in step S1, the heating reflux is heated to 170-185 ℃ for 20-25 h.

As another limitation of the present invention, in step S1, the cooling chromatography uses silica gel column chromatography.

As a further limitation of the present invention, in step S1, the eluent for the cooling chromatography is CS₂And ethyl acetate.

As a third limitation of the present invention, in step S1, the mass ratio of C60, 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine and o-dichlorobenzene is 3: 2: 36-42;

the mass ratio of the product A to carbon tetrachloride is 1: 17-23.

As a fourth limitation of the invention, in step S2, the mass-to-volume ratio of the cage C60, the dimethanol formal, the anhydrous ferric trichloride and the 1, 2-dichloroethane is 25g:4-8g:10-13g: 30L.

As a fifth limitation of the present invention, in step S2,

the low-temperature heating reaction is carried out for 4-6h at 42-48 ℃ under the anaerobic condition;

the high-temperature heating reaction is carried out under the oxygen-free condition of heating at the temperature of 110-;

the solvent for the soxhlet extraction is methanol.

As a sixth limitation of the present invention, the mass volume ratio of ammonium molybdate tetrahydrate, thiourea and water is 20-23g:70-78g: 1L; the mass of the molybdenum disulfide is integral multiple of that of the coupling cage C60, and the molybdenum disulfide is generated by the reaction of ammonium molybdate tetrahydrate and thiourea.

Wherein, the molybdenum disulfide is generated by the reaction of ammonium molybdate tetrahydrate and thiourea in the system participating in the hydrothermal synthesis reaction in the step S3, and the mass of the molybdenum disulfide can be calculated according to the mass of molybdenum element. The loading amount of the molybdenum disulfide is different, and the performance of hydrogen evolution can be influenced to a certain extent.

As another limitation, in step S3, the hydrothermal synthesis reaction is carried out under the conditions of heating to 190 ℃ and 210 ℃ for 17-19h, and the cooling is carried out by reducing the temperature to 20-25 ℃.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the technical progress that:

according to the invention, after the open cage C60 is prepared, the open cage C60 is coupled to form the coupled open cage C60 (namely P-PC60), a rigid framework with a large specific surface area of the P-PC60 is used as a substrate, and the mass ratio of the solution B to the coupled open cage C60 is adjusted to realize that molybdenum disulfide with different mass ratios is doped to prepare the electrocatalytic composite material with different mass fractions.

The P-PC60 has high nitrogen content and a large amount of free electrons, can improve the band gap of molybdenum disulfide, improve the conductivity, can obviously reduce the overpotential of the composite material by adjusting the mass fraction of the two, and the prepared electrochemical hydrogen evolution catalyst has good catalytic activity and stability.

The invention relates to a coupled open cage C60 and molybdenum disulfide composite material, which has the advantages of simple and easily obtained raw materials, obviously reduced preparation cost compared with the preparation cost of platinum group metals, and can be applied to the technical field of electrochemical hydrogen evolution.

The invention is described in further detail below with reference to the figures and the embodiments.

Drawings

FIG. 1 is the [email protected] MoS of example 7₂P-PC60 and MoS₂XRD spectrum of (1);

FIG. 2 is the [email protected] MoS of example 7₂SEM picture of (1);

FIG. 3 is [email protected] MoS of example 7₂P-PC60, Pt/C and MoS₂Electrocatalytic hydrogen evolution performance results of (a); (a) is a linear voltammetric sweep curve, (b) is a tafel slope, (c) is [email protected] MoS₂Electrochemical impedance spectrum, (d) is [email protected] MoS₂A stability test result;

FIG. 4 is [email protected] MoS of example 7₂The results of the stability tests of materials F2-F6.

Detailed Description

Example 1 preparation method of coupled cage C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution

The embodiment comprises the following steps which are carried out in sequence:

s1, preparation of cage opening C60

5.4kg of C60 and 3.6kg of 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine were dissolved in 72kg of O-dichlorobenzene (i.e., O-DCB), heated to 180 ℃ under reflux for 24 hours, cooled to room temperature, and then CS was added₂Directly performing silica gel column chromatography on the eluent to remove unreacted C60, collecting the eluent, performing rotary evaporation, and taking the product A positioned in the second color band, wherein the yield of the product A is 19% by calculation.

Wherein the mass ratio of C60, 3- (2-pyridyl) -5, 6-diphenyl-1, 2, 4-triazine and o-dichlorobenzene (marked as proportion 1) is 3: 2: 40;

dissolving 1kg of the product A in 20kg of carbon tetrachloride, reacting for 72h in an oxygen atmosphere by using a high-pressure mercury lamp, performing rotary evaporation, and separating by adopting the silica gel column chromatography to obtain an open cage C60, wherein the yield of the open cage C60 is 57.6 percent by calculation.

S2, preparation of coupled cage C60

Adding 250g of open cage C60, 57g of dimethanol Formal (FDA) and 120g of anhydrous ferric trichloride into a high-pressure bottle, adding 300L of 1, 2-dichloroethane, reacting at 45 ℃ for 5 hours under an anaerobic condition, heating to react at a low temperature to form a network, reacting at 120 ℃ for 48 hours, heating to react at a high temperature to form a microporous polymer, collecting the product, centrifuging to obtain a lower-layer precipitate, performing Soxhlet extraction with methanol, and vacuum drying for 24 hours to obtain a coupled open cage C60;

wherein the mass volume ratio (marked as the ratio 2) of the open cage C60, the dimethanol formal, the anhydrous ferric trichloride and the 1, 2-dichloroethane is 25g:5.7g:12g: 30L;

the XRD of the resulting coupled cage C60(P-PC60) is shown in FIG. 1.

[email protected]₂Preparation of

Dissolving 220g of ammonium molybdate tetrahydrate and 700g of thiourea in 10L of ultrapure water, and uniformly mixing to obtain a solution B;

coupling the solution B with 100g of the solution B, opening a cage C60 to a hydrothermal kettle, heating the solution B and 100g of the solution B in a muffle furnace to 200 ℃, performing hydrothermal synthesis reaction, reacting for 18h, cooling to 22 ℃, washing the solution B for 5 times by using ultrapure water and absolute ethyl alcohol in sequence, and performing vacuum drying for 14h at 60 ℃ to obtain [email protected] MoS₂Material, labeled F1.

Wherein the mass volume ratio (marked as ratio 3) of ammonium molybdate tetrahydrate, thiourea and water is 22g:70g: 1L;

the mass ratio of the coupling cage C60 to the molybdenum disulfide is 1: 2.

The prepared [email protected] MoS₂The XRD of the material F1 is shown in a figure 1, and the SEM is shown in a figure 2, the material takes a coupled open cage C60 as a rigid framework, the surface of the material is doped with molybdenum disulfide, the action effect of the molybdenum disulfide is improved, and the material can be used as a catalytic electrode to realize electrochemical hydrogen evolution.

Examples 2-6 coupled cage C60 for electrochemical hydrogen evolution and method for preparing molybdenum disulfide composite

Examples 2-6 are a process for preparing coupled cage-opened C60 and molybdenum disulfide composite material for electrochemical hydrogen evolution, respectively, which has the process steps similar to those of example 1, except that: the relevant parameters and results are different, and are shown in table 1.

Table 1 examples 2-6 summary of coupled cage C60 for electrochemical hydrogen evolution and preparation of molybdenum disulfide composites

The other parts of examples 2-6 are the same as in example 1 or are common knowledge to a person skilled in the art. The coupling cage C60 and the molybdenum disulfide have different mass ratios, so that the electrocatalytic composite material F2-6 with different mass fractions can be prepared by doping the molybdenum disulfide with different mass ratios. Wherein the dosage of the molybdenum disulfide is realized by controlling the dosage of the component B of the solution.

Example 7 detection of the Properties of coupled open cage C60 and molybdenum disulfide composite for electrochemical Hydrogen evolution

[email protected] MoS₂P-PC60 and MoS₂Structure of (1)

For [email protected] MoS obtained in example 1₂P-PC60 and MoS₂Detecting XRD pattern for [email protected] MoS₂SEM photograph was taken to examine [email protected] MoS prepared in example 1₂P-PC60 and MoS₂The structure of (1).

The results are shown in FIGS. 1-2, for [email protected] MoS in FIG. 1₂P-PC60 and MoS₂Can see the doping of MoS₂Then, in [email protected] MoS₂In which MoS appears₂The diffraction peaks of (a) indicate successful preparation of the composite. From FIG. 2, MoS can be seen₂The dispersion is good on a P-PC60 substrate, and the good dispersion is beneficial to improving the hydrogen evolution performance of the material.

For [email protected] MoS in examples 2-6₂P-PC60 and MoS₂And (5) carrying out structure detection to obtain an approximate result.

(II) [email protected] MoS₂P-PC60, Pt/C20% and MoS₂Electrocatalytic hydrogen evolution performance of

For [email protected] MoS obtained in example 1₂、P-PC60、MoS₂Electrochemical method using three electrodesThe chemical system uses a Princeton Versa STAT 3 electrochemical workstation to carry out the electro-catalysis hydrogen evolution performance test. The working electrode, the counter electrode and the reference electrode in the three-electrode system refer to: glassy carbon electrode (GCE,4mm), Pt/C20% and Ag/AgCl (sat. KCl). Wherein, 0.3 mu mAl should be used before the working electrode is used₂O₃The powder is ground. The preparation method of the working electrode comprises the following steps: measuring 5mg of a sample to be measured in a glass bottle, adding 950 mu L of absolute ethyl alcohol and 50 mu L of Nafion solution, carrying out ultrasonic treatment for 30 minutes to uniformly disperse, measuring 5 mu L of the solution, dropwise adding the solution onto the electrode which is polished before, and naturally drying.

(i) Linear voltammetric sweep curve detection

For [email protected] MoS obtained in example 1₂、P-PC60、MoS₂H at 0.5M₂SO₄The electrolyte solution of (3) is measured. Linear voltammetric sweep at a sweep rate of 5mVs^-1The interval is 0 to-1V.

As a result, the graph shows MoS from left to right as shown in FIG. 3(a)₂,P-PC60,[email protected]₂And Pt/C20% linear voltammetric sweep, the results show that [email protected] MoS₂At a current density of 10mA cm^-2The overpotential is 116mV, and the electrocatalytic performance is good.

(ii) Tafel slope detection

The tafel slope is a straight line calculated from the tafel equation (η ═ a + blgj, where j is the current density, η is the overpotential, b is the tafel slope, and a and b are tafel constants) based on the polarization curve obtained by linear sweep voltammetry, for [email protected] MoS prepared in example 1₂、P-PC60、MoS₂。

As a result, MoS is shown in FIG. 3(b)₂The Tafel slopes of P-PC60, Pt/C20% are 138mV · dec, respectively^-1，132mV·dec^-1And 30mV dec^-1[email protected] MoS of example 1 of the present invention₂The Tafel slope is 43mV dec^-1And has good electrocatalytic performance.

(iii)[email protected]₂Electrochemical impedance spectrogram detection

Prepared for example 1 at a disturbance amplitude of 5mV at 0.3-100k [email protected] MoS₂And (5) carrying out electrochemical impedance spectrogram test.

The results are shown in FIG. 3(c), and indicate that [email protected] MoS₂The electrochemical impedance of the catalyst is 300 omega, and the catalyst has good electrocatalytic performance.

(iiii)[email protected]₂Stability detection

For [email protected] MoS₂And circulating for 2000 circles to obtain a stability test chart in a scanning potential range of 0 to-1V and at a scanning speed of 100 mV/s.

The results are shown in FIG. 3(d), and indicate that [email protected] MoS₂Has good catalytic stability. For [email protected] MoS prepared in examples 2-6₂P-PC60 and MoS₂Similar measurements were made, and all gave similar results, as shown in FIG. 4, for [email protected] MoS obtained in examples 2-6₂The hydrogen evolution performance of F2-F6 shows the trend of rising firstly and then falling along with the increase of X, and the performance of the F2-F6 is superior to that of a pure molybdenum disulfide material; meanwhile, the hydrothermal temperature also has a certain influence on the hydrogen evolution performance.

The above results indicate that [email protected] MoS of F1-6₂The material has good stability and high catalytic activity, and provides a theoretical basis for replacing a Pt catalyst to realize industrialized large-scale hydrogen production. [email protected] MoS₂The electrocatalytic composite material provides guiding significance for non-noble metal materials in the electrocatalytic field due to good electrocatalytic performance and a simple preparation method.

Although the present invention has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described above, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.