Electrocatalytic water oxidation homogeneous diatomic catalyst, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical fields of electrocatalysis and chemical industry, and specifically relates to an electrocatalytic water oxidation homogeneous diatomic catalyst, and a preparation method therefor and a use thereof. The catalyst comprises a carrier and a homogeneous diatomic active site having an adjacency structure, and the active site is anchored in the carrier; the carrier is at least one of an oxide, a hydroxide and an oxyhydroxide of a 3d transition-metal; a coordination structure is formed between the double atoms and the carrier. The intrinsic activity of a diatomic dispersed catalytic material prepared by the method in an electrocatalytic water oxidation reaction is equivalent to that of the existing natural photosynthetic system II having the highest efficiency, at the same time, the water oxidation initial potential is merely 170 mV, and the stability is kept for 650 h under a current density of 20 A cm−2; and the preparation method is simple and has low cost.

Description

TECHNICAL FIELD

[0001] The present invention belongs to the fields of electrocatalysis and chemical industry, and in particular to an electrocatalytic water oxidation homogeneous diatomic catalyst, and a preparation method therefor and a use thereof.BACKGROUND

[0002] One of the most important measures to replace fossil energy to achieve the goal of “carbon peaking and carbon neutrality” is to use renewable energy such as solar energy to generate electricity, which convert a series of small molecules such as H2O, CO2, N2, and O2 into high value-added fuels and chemicals. It can not only alleviate the energy shortage caused by excessive use of fossil fuels, but also improve the environmental problems caused by combustion of fossil fuels. Taking water electrolysis for hydrogen production as an example, the hydrogen energy industry has become an important part of China's energy strategic layout. Hydrogen energy can effectively connect and replace fossil resources from technical routes, and can promote the energy transformation process in the three roles of “secondary energy, energy carrier, and low-carbon raw material”. By 2050, the demand for “green hydrogen” in the whole society may be close to 100 million tons. At present, China's hydrogen energy industry mainly comes from “gray hydrogen” (accounting for about 95% of the total output). Although gray hydrogen is cheaper to produce and technically simple, it needs to be prepared by fossil fuels (such as natural gas), and a large amount of CO2 and other greenhouse gases are emitted in the production process. However, green hydrogen production from water electrolysis using renewable clean energy such as solar energy and wind power can achieve zero carbon emissions, with characteristics of green environmental protection, flexible production and high purity, and has unparalleled advantages. In the existing water electrolysis technologies, alkaline electrolysis technology is the most mature, but its unit energy consumption is high (the electricity price accounts for more than 70% of the total cost). The most critical reason is that the water electrolysis catalyst has high overpotential and poor long-term stability. The water electrolysis process consists of two half-reactions-cathodic hydrogen evolution reaction and anodic water oxidation reaction. Water oxidation is a multi-step reaction process of multi-electron, multi-proton and its kinetics is slow, which is the rate-determining step of the reaction. At present, most water oxidation catalysts have an initial overpotential above 250 mV, an intrinsic activity TOF (turnover frequency) below 1 s−1, and a poor stability, limiting their large-scale application of hydrogen production from water electrolysis.

[0003] Monatomic catalysts developed in recent years have advantages of 100% atomic utilization, unique electronic structure, high activity, etc., and have received a great deal of attention in water oxidation catalyst development. Monatomic catalysts currently reported include noble metal elements (such as Ru, Ir, Ni, Fe, and the like) and non-noble metal elements, and carriers include carbon materials, hydroxides, phosphides, and the like. However, since the higher energy barrier and complex reaction path of water oxidation reaction, monatomic catalysts currently reported have high overpotentials, low TOF values, and poor stabilities. Therefore, it is of great significance to explore cheap electrocatalytic water oxidation catalysts with high activity and high intrinsic activity for industrial applications in a series of energy catalytic conversion processes such as water electrolysis for hydrogen production.SUMMARY OF THE INVENTION

[0004] An object of the present invention is to provide a homogeneous diatomic catalyst, and a preparation method therefor and a use thereof. The catalyst provided by the present invention not only has a simple preparation method, but also has high intrinsic activity, good universality, high stability and low cost.

[0005] To achieve the above object, technical solutions adopted by the present invention are as follows:

[0006] One aspect of the present invention provides a homogeneous diatomic catalyst including a carrier and a homogeneous diatomic active site having an adjacency structure. The active site is anchored in the carrier. The carrier is at least one of oxide, hydroxide and oxyhydroxide of 3d transition-metal. A coordination structure is formed between the homogeneous diatomics and the carrier.

[0007] According to the present invention, at least on of an oxide, a hydroxide or an oxyhydroxide of a 3d transition-metal is synthesized first as a carrier, a precursor having a definite metal dimer structure is then mixed with the carrier of the oxide or hydroxide of a 3d transition-metal, and diatomic active sites are embedded into the 3d transition-metal material skeleton through calcination treatment to obtain a loaded structure having a homogeneous diatomic structure in which the diatomics are adjacent ions having oxidation state, and a stable coordination structure is formed between the diatomics and the carrier.

[0008] In the above technical solution, further, the 3d transition-metal is at least one of Ti, V, Mn, Fe, Co, Ni, Cu and Zn, preferably at least one of V, Mn, Fe, Co and Ni.

[0009] In the above technical solution, further, atoms of the homogeneous diatomics are the same metal element, and in the catalyst, the atomic specie of the diatomics is at least one of Ir, Ru, Ni, Fe, Co and Mn, preferably at least one of Ir, Ni, Fe and Co.

[0010] In the above technical solution, further, a distance between the atoms of the homogeneous diatomics is 1.5-3.5 Å, preferably 2.5-3.3 Å

[0011] In the above technical solution, further, a metal loading of the homogeneous diatomics is 0.1-5.0 wt. %, preferably 0.2-2.0 wt. %.

[0012] In the above technical solution, further, a coordination number of the homogeneous diatomics is 3.0-6.0, preferably 4.0-5.0.

[0013] In the above technical solution, further, an existing form of the homogeneous diatomics is ionic state, with a valence state ranging from +2 to +7, preferably from +2 to +5.

[0014] Another aspect of the present invention provides a method for preparing the homogeneous diatomic catalyst. The method includes the following steps:

[0015] S1. Disperse the carrier in a solvent I to prepare a suspension A;

[0016] S2. Dissolve a metal dimer precursor in a solvent II to obtain a solution, slowly add the solution into the suspension A with fully mixing to obtain a mixture, and then remove the solvent in the mixture by means of at least one of filtration, centrifugation, freeze-drying, rotary evaporation and heating evaporation to obtain a product B;

[0017] S3. Calcine the product B after grinding, and obtain the catalyst.

[0018] In the above technical solution, further, in step S1, a mass ratio of the carrier and the solvent I is 1:10-1:10000, preferably 1:100-1:500.

[0019] The solvent I is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, methylphenyl cyclohexanone, acetone, methyl butanone, methyl isobutyl ketone, acetonitrile and pyridine.

[0020] In the above technical solution, further, in step S2, the metal dimer precursor has a structural formula shown as Formula I.wherein, M is a metal including at least one of Ir, Ru, Ni, Fe, Co and Mn, R is a coordination atom including any one of O, Cl, C, N, P and S, a valence state of the metal in the metal dimer precursor is 0 to +5, the distance between the metal atoms is 1.5 to 3.5 Å, and a coordination number of the metal atoms is 2 to 7.

[0022] The solvent II is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, tolylcyclohexanone, acetone, methylbutanone, methyl isopropyl ketone, acetonitrile and pyridine.

[0023] A mass ratio of the metal to the carrier in the metal dimer precursor is 1:20 to 1:1000, preferably 1:50-1:500.

[0024] A mass ratio of the metal dimer precursor to the solvent II is 1:10 to 1:1000, preferably 1:200-1:500.

[0025] In the above technical solution, further, in step S3, a calcination atmosphere is at least one of air, oxygen, nitrogen and argon, a calcination temperature is 100-1200° C., and a calcination time is 10 min-10 h.

[0026] Still another aspect of the present invention provides a use of the homogeneous diatomic catalyst in (photocatalysed) water electrolysis for hydrogen production, (photocatalysed) electrocatalytic carbon dioxide reduction, and (photocatalysed) electrocatalytic nitrogen reduction.

[0027] Beneficial effects of the present invention are as follows:

[0028] 1. The preparation method according to the present invention is simple, and the catalyst prepared has good performance, especially high intrinsic activity, good universality and high stability, and has low cost.

[0029] 2. According to the present invention, a homogeneous diatomic (such as Ir, Ru, Ni, Fe, Co, Mn) catalyst loaded with 3d transition-metal oxide / hydroxide / oxyhydroxide can be obtained, wherein the homogeneous diatomics has an adjacently pairwise distributed atom pair structure of the same metal, and the prepared catalyst shows excellent catalytic performance in electrocatalytic water oxidation reactions.

[0030] 3. The catalyst prepared according to the present invention has a homogeneous diatomic metal mainly in an ionic state, the interatomic distance is controllable, the loading amount of diatomics is easily regulated and controlled, and the preparation method is simple and easy for large-scale production. The catalytic performance of the homogeneous diatomic dispersed catalytic material prepared by the method according to the present invention in electrocatalytic water oxidation can be comparable to that of the natural photosystem II, and has good catalytic stability, having good promise of application.

[0031] 4. The water oxidation initial potential of the catalyst of the present invention is merely 170 mV, and the catalyst can be stable for 650 h under a current density of 20 mA cm−2.DETAILED DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a SEM (scanning electron microscope) diagram of the CoOx-loaded diatomic Ru catalyst according to Example 1.

[0033] FIG. 2 is a HAADF-STEM (high-angle annular dark-field-scanning transmission electron microscopy) diagram of the CoOx-loaded diatomic Ru catalyst according to Example 1.

[0034] FIG. 3 shows extended edge fitting results of Ru EXAFS (extended X-ray absorption fine structure) spectra of the diatomic catalyst Ru2—NiOx according to Example 2.

[0035] FIG. 4 shows the electrocatalytic water oxidation activity of the diatomic catalyst Ru2—NiOx according to Example 2 compared with that of commercial IrO2, NiOx and monatomic Ru1—NiOx.

[0036] FIG. 5 shows the electrocatalytic water oxidation initial overpotential and TOF of the diatomic catalyst Mn2—Ni(OH)2 according to Example 3 compared with commercial IrO2, Ni(OH)2 and monoatomic Mn1—Ni(OH)2.

[0037] FIG. 6 shows the stability of the diatomic catalyst Mn2—Ni(OH)2 according to Example 2 at a current density of 20 mA cm 2.

[0038] FIG. 7 shows the stability of the diatomic catalyst Mn2—CoOOH according to Example 6 at a current density of 20 mA cm−2.DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] In order to further illustrate the present invention, the following embodiments are set forth in conjunction with the accompanying drawings, which do not limit the scope of the present invention as defined by the Claims.

[0040] Unless otherwise specified, the means used in the embodiments are well known in the field.Example 1

[0041] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal CoOx oxide carrier and a diatomic active center ruthenium (Ru), and the diatomic active center is anchored in the CoOx oxide carrier.

[0042] The method for preparing the above catalyst includes the following steps:

[0043] (1) 12 mmol of cetyl trimethyl ammonium bromide (CTAB) was dissolved in 25 mL of water, 1 mmol of cobalt nitrate hexahydrate was added therein and stirred for 15 min, and a solution A was obtained.

[0044] (2) 1.5 mmol of sodium borohydride was added into the solution A and fully stirred for 6 h to obtain a product, and then the product was dried after washing with water and ethanol, and a CoOx carrier was obtained.

[0045] (3) 20 mg of CoOx carrier was weighed and dispersed in 10 mL of ethanol, then 1 mg of dichlorophenyl ruthenium (II) dimer was added therein to obtain a mixture, the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove solvent, and a mixture B was obtained.

[0046] (4) The mixture B was put into a tubular furnace for calcination in an air environment at 300° C. for 5 h, and a CoOx loading diatomic Ru electrocatalytic water oxidation catalyst was finally obtained.

[0047] It can be seen from the SEM diagram and the HAADF-STEM diagram shown in FIG. 1 and FIG. 2 that the metal Ru in the prepared catalyst is mainly in the form of diatomics dispersed in a CoOx skeleton.Example 2

[0048] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal NiOx oxide carrier and a diatomic active center Ru, and the diatomic active center is anchored in the NiOx oxide carrier.

[0049] The method for preparing the above catalyst includes the following steps:

[0050] (1) 12 mmol of CTAB was dissolved in 25 mL of water, 1 mmol of nickel nitrate hexahydrate was added therein and stirred for 15 min, and a solution A was obtained.

[0051] (2) 1.5 mmol of sodium borohydride was added into the solution A and fully stirred for 6 h to obtain a product, and then the product was dried after washing with water and ethanol, and a NiOx carrier was obtained.

[0052] (3) 20 mg of NiOx carrier was weighed and dispersed in 10 mL of ethanol, then 1 mg of dichlorophenyl ruthenium (II) dimer was added therein to obtain a mixture, the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove solvent, and a mixture B was obtained.

[0053] (4) The mixture B was put into a tubular furnace for calcination in an air environment at 300° C. for 5 h, and a NiOx loading diatomic Ru electrocatalytic water oxidation catalyst was finally obtained.

[0054] The extended edges and fitting results of the synchronous radiation X-ray absorption spectrum shown in FIG. 3 and Table 1 show that the distance between Ru and Ru in the homogeneous diatomic Ru structure is 3.1 Å.TABLE 1σ2 ΔE0 R SamplePathCNR (Å)(×10−3 Å2)(eV)(%)Ru1 / Ru—O12.0 ± 1.21.84 ± 0.068.07.81 ±0.3CoOxRu—O26.3 ± 1.02.03 ± 0.024.03.35Ru—Cl1.1 ± 0.92.43 ± 0.085.0Ru—Co0.8 ± 0.62.55 ± 0.033.0Ru—Ru1.6 ± 1.12.83 ± 0.046.0Ru2 / Ru—O15.2 ± 0.81.99 ± 0.012.4 ± 1.19.98 ±0.6CoOxRu—Co14.6 ± 2.12.97 ± 0.0212.50.76Ru—Ru1.9 ± 1.73.09 ± 0.022.8Ru—O211.3 ± 3.0 3.63 ± 0.0315.0Example 3

[0055] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal Ni(OH)2 hydroxide carrier and a diatomic active center manganese (Mn), and the diatomic active center is anchored in the Ni(OH)2 carrier.

[0056] The method for preparing the above catalyst includes the following steps:

[0057] (1) 0.4 g of NiCl2 was added to 40 mL of ethanol, and then was heated at 150° C. for 12 h after fully stirring to obtain Ni(OH)2. The obtained Ni(OH)2 was ultrasonically exfoliated in an ethanol solution for 24 h, followed by centrifuging and drying to obtain a two-dimensional Ni(OH)2 nanosheet carrier.

[0058] (2) 20 mg of Ni(OH)2 carrier was weighed and dispersed in 10 mL of ethanol, then 1 mg of tricarbonyl (H-cyclopentadienyl) manganese dimer was added therein to obtain a mixture, and the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove the solvent to obtain a mixture A.

[0059] (3) The mixture A was put in a tubular furnace for calcination in an air environment at 100° C. for 5 h, and a Ni(OH)2 loading diatomic Mn electrocatalytic water oxidation catalyst was finally obtained.Example 4

[0060] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal CoOOH oxyhydroxide carrier and a diatomic active center Mn, and the diatomic active center is anchored in the CoOOH carrier.

[0061] The method for preparing the above catalyst includes the following steps:

[0062] (1) 0.3 g of Co(NO3)2·6H2O was added to 200 ml of water followed by fully stirring, 30 mL of 1M NaOh was added therein and was stirred for 30 min, and 6 mL of NaOCl was then added therein and stirred for 1 h, and a precipitate was obtained. The obtained precipitate was collected by means of centrifugation and washing, and was dried to obtain CoOOH.

[0063] (2) 20 mg of CoOOH carrier was weighed and dispersed in 10 mL of ethanol, then 1 mg of tricarbonyl (H-cyclopentadienyl) manganese dimer was added therein to obtain a mixture, and the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove the solvent to obtain a mixture A.

[0064] (3) The mixture A was put in a tubular furnace for calcination in an air environment at 100° C. for 5 h, and a CoOOH loading diatomic Mn electrocatalytic water oxidation catalyst was finally obtained.Example 5

[0065] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal CoOOH oxyhydroxide carrier and a diatomic active center Mn, and the diatomic active center is anchored in the CoOOH carrier.

[0066] The method for preparing the above catalyst includes the following steps:

[0067] (1) 0.3 g of Co(NO3)2·6H2O was added to 200 ml of water followed by fully stirring, 30 mL of 1M NaOh was added therein and was stirred for 30 min, and 6 mL of NaOCl was then added therein and stirred for 1 h, and a precipitate was obtained. The obtained precipitate was collected by means of centrifugation and washing, and was dried to obtain CoOOH.

[0068] (2) 20 mg of CoOOH carrier was weighed and dispersed in 10 mL of ethanol, then 1 mg of tricarbonyl (H-cyclopentadienyl) manganese dimer was added therein to obtain a mixture, and the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove the solvent to obtain a mixture A.

[0069] (3) The mixture A was put in a tubular furnace for calcination in an air environment at 100° C. for 5 h, and a CoOOH loading diatomic Mn electrocatalytic water oxidation catalyst was finally obtained.Example 6

[0070] This example provides an electrocatalytic water oxidation homogeneous diatomic catalyst, which includes a 3d transition-metal CoOOH oxyhydroxide carrier and a diatomic active center Mn, and the diatomic active center is anchored in the CoOOH carrier.

[0071] The method for preparing the above catalyst includes the following steps:

[0072] (1) 0.3 g of Co(NO3)2·6H2O was added to 200 mL of water followed by fully stirring, 30 mL of 1M NaOh was added therein and was stirred for 30 min, and 6 mL of NaOCl was then added therein and stirred for 1 h, and a precipitate was obtained. The obtained precipitate was collected by means of centrifugation and washing, and was dried to obtain CoOOH.

[0073] (2) 30 mg of CoOOH carrier was weighed and dispersed in 10 mL of ethanol, then 2 mg of tricarbonyl (H-cyclopentadienyl) manganese dimer was added therein to obtain a mixture, and the mixture was fully sonicated for 1 h and stirred for 10 h and was then heated at 70° C. to remove the solvent to obtain a mixture A.

[0074] (3) The mixture A was put in a tubular furnace for calcination in an environment of 50% of air and 50% of oxygen at 100° C. for 5 h, and a CoOOH loading diatomic Mn electrocatalytic water oxidation catalyst was finally obtained.Text Example 1

[0075] The catalytic material prepared in the Example 2 was tested and evaluated in electrocatalytic water oxidation. Test conditions were as follows: using an electrochemical workstation from Shanghai Chenghua Instruments Co., Ltd., with a catalyst loading of 1 mg cm−2, and an electrolyte of 1M KOH.

[0076] FIG. 4 shows the electrocatalytic water oxidation activity of the diatomic catalyst Ru2—NiOx according to Example 2 compared with that of commercial IrO2, NiOx and monatomic Ru1—NiOx. It can be seen from FIG. 4 that diatomic structured Ru2—NiOx has lower overpotential and higher electrocatalytic water oxidation performance than commercial IrO2, NiOx and monatomic Ru1—NiOx. Therefore, compared with catalysts prepared by traditional methods, the intrinsic catalytic performance TOF of the diatomic catalytic material prepared in the present invention in electrocatalytic water oxidation reaction is improved by 2-3 orders of magnitude, having a high industrial prospect.Text Example 2

[0077] The catalytic material prepared in the Example 2 was tested and evaluated in electrocatalytic water oxidation. Test conditions were as follows: using an electrochemical workstation from Shanghai Chenghua Instruments Co., Ltd., with a catalyst loading of 1 mg cm−2, and an electrolyte of 1M KOH.

[0078] The Ni(OH)2 loading diatomic Mn catalyst shown in FIG. 5 shows a lower overpotential and a higher TOF value than commercial IrO2, NiOx and monatomic Ru1—NiOx.Text Example 3

[0079] The catalytic material prepared in the Example 2 was tested and evaluated in electrocatalytic water oxidation. Test conditions were as follows: using an electrochemical workstation from Shanghai Chenghua Instruments Co., Ltd., with a catalyst loading of 1 mg cm−2, and an electrolyte of 1M potassium borate.

[0080] FIG. 6 shows that supporting the diatomic catalyst Mn2—CoOOH as a co-catalyst on the BiVO4 photoanode results in a significant improvement in the performance of the photoelectrocatalytic decomposition of water, much higher than the performance of the photoanode using CoOOH as the catalyst.Text Example 4

[0081] The catalytic material prepared in the Example 2 was tested and evaluated in electrocatalytic water oxidation. Test conditions were as follows: using an electrochemical workstation from Shanghai Chenghua Instruments Co., Ltd., with a catalyst loading of 1 mg cm−2, and an electrolyte of 1M KOH.

[0082] It can be seen form FIG. 7 that the CoOOH loading diatomic Mn catalyst shows high stability over 650 h at a current density of 20 mA cm−2.

[0083] The applicant states that the present invention illustrates the detailed methods of the present invention through the above embodiments, but the present invention is not limited to the detailed methods, that is, it is not mean that the present invention must be implemented depending on the above detailed methods. Those skilled in the art should understand that, for any improvements of the present invention, equivalent replacements of the various raw materials of the products of the present invention, addition of auxiliary components, selection of specific manners and the like, all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A homogeneous diatomic catalyst, comprising a carrier and a homogeneous diatomic active site having an adjacency structure, and the active site is anchored in the carrier, wherein the carrier is at least one of oxide, hydroxide, and oxyhydroxide of 3d transition-metal, and a coordination structure is formed between the diatomics and the carrier.

2. The homogeneous diatomic catalyst according to claim 1, wherein the 3d transition-metal is at least one of Ti, V, Mn, Fe, Co, Ni, Cu and Zn; and atoms of the homogeneous diatomics are identical metal element, and in the catalyst, the atomic specie of the diatomics is at least one of Ir, Ru, Ni, Fe, Co and Mn.

3. The homogeneous diatomic catalyst according to claim 1, wherein a interatomic distance of the homogeneous diatomics is 1.5 to 3.5 Å.

4. The homogeneous diatomic catalyst according to claim 1, wherein a metal loading of the homogeneous diatomics is 0.1-5.0 wt. %.

5. The homogeneous diatomic catalyst according to claim 1, wherein a coordination number of the homogeneous diatomics is 3.0-6.0, and an existing form of the homogeneous diatomics is ionic state with a valence state ranging from +2 to +7.

6. A method for preparing the homogeneous diatomic catalyst according to claim 1, comprising the following steps of:S1) dispersing the carrier in a solvent I to prepare a suspension A;S2) dissolving a metal dimer precursor in a solvent II to obtain a solution, slowly adding the solution into the suspension A with fully mixing to obtain a mixture, and then removing the solvent in the mixture by means of at least one of filtration, centrifugation, freeze-drying, rotary evaporation, and heating evaporation to obtain a product B; andS3) calcining the product B after grinding, and obtain the catalyst.

7. A method according to claim 6, wherein in step S1, a mass ratio of the carrier and the solvent I is 1:10-1:10000; andthe solvent I is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, methylphenyl cyclohexanone, acetone, methyl butanone, methyl isobutyl ketone, acetonitrile, and pyridine.

8. The method according to claim 6, wherein in step S2, the metal dimer precursor has a structural formula as follows:wherein, Mis a metal comprising at least one of Ir, Ru, Ni, Fe, Co and Mn, R is a coordination atom comprising any one of O, Cl, C, N, P and S, a valence state of the metal in the metal dimer precursor is 0 to +5, the distance between the metal atoms is 1.5 to 3.5 Å, and a coordination number of the metal atoms is 2 to 7;the solvent II is at least one of water, benzene, toluene, xylene, chlorobenzene, dichlorobenzene, methanol, ethanol, isopropanol, cyclohexanone, tolylcyclohexanone, acetone, methylbutanone, methyl isopropyl ketone, acetonitrile, and pyridine;a mass ratio of the metal to the carrier in the metal dimer precursor is 1:20 to 1:1000; anda mass ratio of the metal dimer precursor to the solvent II is 1:10 to 1:1000.

9. The method according to claim 6, wherein in step S3, a calcination atmosphere is at least one of air, oxygen, nitrogen and argon, a calcination temperature is 100-1200° C., and a calcination time is 10 min-10 h.

10. A use of the homogeneous diatomic catalyst according to claim 1 in (photocatalysed) water electrolysis for hydrogen production, (photocatalysed) electrocatalytic carbon dioxide reduction, and (photocatalysed) electrocatalytic nitrogen reduction.

Images