A nickel-based selenide nano-island confined Pt single-atom catalyst and its preparation method

Abstract

The present invention discloses a nickel-based selenide nano-island confined Pt single-atom catalyst and a preparation method thereof, wherein the catalyst comprises a carrier and an active center; the carrier is a nickel-based selenide nano-island; the active center is Pt; the Pt metal atom is confined within the nickel-based selenide nano-island; the Pt metal exists in the form of a single atom. The present invention also discloses a preparation method for the above-mentioned catalyst, which adopts a simple two-step method, that is, a platinum single-atom catalyst supported on a nickel selenide nano-island can be prepared by hydrothermal and electrodeposition. The catalyst prepared by the present invention has nanoclusters with abundant defect sites, which enhance the beneficial effect of anchoring, thereby improving the performance of hydrogen evolution by electrolysis of water under alkaline conditions; the obtained catalyst is Pt1 / NiSe.

Description

Technical Field

[0001] The invention belongs to the technical field of nanocatalyst synthesis, and in particular relates to a nickel-based selenide nano-island confined Pt single-atom catalyst and a preparation method thereof. Background Art

[0002] In order to alleviate CO2 emissions and reduce fossil fuel consumption, it is urgent to find green, clean and pollution-free renewable energy. In recent years, hydrogen energy has strategic significance in alleviating energy crisis, improving environmental pollution and adjusting national energy structure due to its wide sources, high energy density and only water as combustion product. The sources of hydrogen are diversified, among which water electrolysis technology fundamentally solves the dependence on fossil fuels and realizes the conversion from H2O to high-purity H2. However, the hydrogen evolution reaction (HER) on the cathode still lacks efficient electrocatalysts, especially in alkaline media, where HER is limited by the additional H-OH dissociation energy barrier, thus showing a slow kinetic reaction process and reducing the efficiency of water electrolysis. At present, traditional precious metal platinum-based materials are considered to be excellent HER electrocatalysts, but their scarcity and high cost seriously hinder large-scale industrial applications. Therefore, the development of low-cost, high-stability and high-activity electrocatalysts remains a challenging task.

[0003] Shrinking metal nanoparticles or clusters to the atomic level is conducive to reducing catalyst costs (especially precious metals), obtaining uniform active sites, improving atom utilization efficiency, maximizing reactant interactions, and correlating structural activity, thus deriving single atom catalysts (SACs). In recent years, single atom catalysts have been widely used in HER due to their high activity, maximized atom utilization, and minimized catalyst usage. The metal atoms in single atom catalysts need to be highly dispersed on a suitable carrier. However, the sharp increase in specific surface area leads to a sharp increase in metal surface free energy. During preparation and reaction, isolated metal atoms are very likely to aggregate and couple on the carrier surface to form clusters, reducing the number of active sites and reducing HER catalytic efficiency and stability. One of the effective ways to solve this problem is to find suitable carrier materials to provide abundant anchoring sites for single atoms and avoid aggregation. Nickel-based catalysts have good application prospects in hydrogen production by water electrolysis due to their high catalytic activity, high conductivity, and low price. Therefore, there is an urgent need to develop a nickel-based selenide carrier confined single-atom catalyst with a special structure, in which atomically dispersed metal atoms can be confined in nano-islands with a special structure, so as to achieve uniform dispersion and firm fixation on a high specific surface area carrier, thereby enhancing the electrocatalytic hydrogen evolution performance. Summary of the invention

[0004] The first technical problem to be solved by the present invention is to provide a nickel-based selenide nano-island confined Pt single atom catalyst.

[0005] The second technical problem to be solved by the present invention is to provide a method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst; the preparation method adopts a simple two-step method, that is, by hydrothermal and electrodeposition, a platinum single-atom catalyst supported on a nickel selenide nano-island can be prepared, and the nanoclusters with abundant defect sites enhance the beneficial effect of anchoring, thereby improving the performance of hydrogen evolution by electrolysis of water under alkaline conditions. The catalyst obtained by the present invention is Pt1 / NiSe, and Pt exists in the form of a single atom.

[0006] In order to solve the above-mentioned first technical problem, the present invention adopts the following technical solution:

[0007] A nickel-based selenide nano-island confined Pt single-atom catalyst, comprising a carrier and an active center;

[0008] The carrier is a nickel-based selenide nano-island;

[0009] The active center is Pt;

[0010] The Pt metal atoms are confined within the nickel-based selenide nano-islands;

[0011] The Pt metal exists in the form of a single atom.

[0012] To solve the above second technical problem, the present invention adopts the following technical solution:

[0013] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0014] S1: Soaking nickel foam (NF) in a hydrochloric acid solution to remove the oxide layer that may exist on the surface, and then ultrasonically cleaning with deionized water and ethanol to obtain a cleaned nickel foam for standby use;

[0015] S2, mixing and stirring the selenium powder and the reducing agent, and then adding them into deionized water to form a mixed solution;

[0016] S3, transferring the mixed solution and the cleaned nickel foam into a polytetrafluoroethylene-lined autoclave, performing hydrothermal treatment, and vacuum drying after the hydrothermal treatment to obtain a transition metal selenide carrier;

[0017] S4. Use the transition metal selenide carrier as the working electrode, perform electrochemical deposition under alkaline conditions, and obtain the nickel-based selenide nano-island confined Pt single atom catalyst after vacuum drying.

[0018] As a further improvement of the technical solution, in step 1), the concentration of the hydrochloric acid solution is 1-3M, and the immersion time is 0.3-0.5h.

[0019] Preferably, in step 1), the ultrasonic cleaning conditions are: 40%-80% of 400W power, for 0.5-1h.

[0020] As a further improvement of the technical solution, in step 2), the reducing agent is hydrazine hydrate.

[0021] Preferably, in step 2), the mass / volume ratio of the selenium powder to hydrazine hydrate is 40-100 mg:5 mL; the stirring rate is 800-1200 r / min, and the stirring time is 10-12 h; the mass / volume ratio of the selenium powder to deionized water is 79 mg:20-30 mL.

[0022] As a further improvement of the technical solution, in step 3), the temperature of the hydrothermal treatment is 180-200°C, and the time of the hydrothermal treatment is 8-12 hours; the temperature of the vacuum drying is 40-60°C, and the drying time is 12-24 hours.

[0023] As a further improvement of the technical solution, in step 4), the working electrode is a selenide carrier directly grown on nickel foam, the counter electrode is a carbon rod, the reference electrode is Hg / HgO, and the electrolyte is a mixed solution containing a platinum metal precursor and KOH.

[0024] Preferably, the mixed solution containing the platinum metal precursor and KOH is a mixed solution obtained by weighing 50-100 mg of potassium chloroplatinite, a platinum metal precursor, and dispersing it in 50-100 mL of 1M KOH electrolyte.

[0025] Preferably, in step 4), the electrochemical deposition adopts chronoamperometry, the reversible hydrogen voltage interval applied by the chronoamperometry is [-0.457V, -0.417V], and the deposition time is 300-900s.

[0026] Preferably, in step 4), the vacuum drying temperature is 40-60° C., and the drying time is 12-24 h.

[0027] Any range described in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0028] Unless otherwise specified, all raw materials in the present invention can be purchased from the market, and the equipment used in the present invention can adopt conventional equipment in the relevant field or refer to the existing technology in the relevant field.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The preparation method of the present invention adopts a simple two-step method, that is, through a hydrothermal method and an electrodeposition method, the nickel foam is used as both a conductive substrate and a nickel source, so that the active material and the substrate can be closely connected, ensuring efficient electron transmission and stability. First, a nickel selenide carrier directly grown on the nickel foam is synthesized by a hydrothermal selenization method, and the optimization of the carrier is achieved by changing the ratio of selenium powder to a reducing agent and reaction time. The synthesized nickel selenide is a well-crystallized nanocluster with an average particle size of less than 5nm. Then, by a constant current electrodeposition method, the metal precursor concentration and the deposition time are adjusted to accurately control the loading amount of Pt single atoms, thereby selectively and stably anchoring single atoms on defective nickel selenide nano islands, effectively avoiding the aggregation of single atoms. TEM showed that the catalyst surface did not have obvious granularity, confirming that the Pt atoms were evenly dispersed; further HAADF-STEM showed a small particle size, dispersed nano-island structure, isolated and densely distributed on a high specific surface area substrate; XRD results confirmed that the crystal phase diffraction peak belonged to the nickel selenide material, and no crystal phase diffraction peak of the Pt particles was detected, indicating the existence of Pt single atoms; combined with XPS, it was confirmed that the Pt atom existed in an oxidation state between 0 valence and +2 valence, and no Pt metal valence state appeared, which fully demonstrated that Pt was loaded on the nickel-based selenide substrate material in the form of a single atom, and the special nano-island structure of nickel selenide was conducive to the precise anchoring and uniform dispersion of Pt single atoms; finally, the performance tests such as LSV polarization curves and Tafel slopes proved that the catalyst had faster reaction kinetics and higher intrinsic catalytic activity for hydrogen evolution under alkaline conditions. The nickel-based selenide nano-island confined Pt single atom catalyst obtained by the present invention has excellent application prospects in electrocatalytic hydrogen evolution reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0032] Figure 1 TEM images of the nickel-based selenide before and after electrodeposition corresponding to Example 1;

[0033] Figure 2 It is a high-angle annular dark field imaging image of nickel-based selenide before and after electrodeposition corresponding to Example 1;

[0034] Figure 3 is the elemental analysis diagram of the nickel-based selenide catalyst corresponding to Example 1;

[0035] Figure 4 is the X-ray diffraction pattern of the nickel-based selenide before and after electrodeposition corresponding to Example 1;

[0036] Figure 5 is the X-ray photoelectron spectrum of the nickel-based selenide before and after electrodeposition corresponding to Example 1;

[0037] Figure 6 is the X-ray photoelectron spectrum of the Pt element of the nickel-based selenide catalyst corresponding to Example 1;

[0038] Figure 7 is the X-ray photoelectron spectrum of the Ni element of the nickel-based selenide catalyst corresponding to Example 1;

[0039] Figure 8 is the X-ray photoelectron spectrum of the Se element of the nickel-based selenide catalyst corresponding to Example 1;

[0040] Fig. 9 is the X-ray photoelectron spectrum of the O element of the nickel-based selenide catalyst corresponding to Example 1;

[0041] Fig.10 is a performance curve diagram of nickel-based selenide before and after electrodeposition corresponding to Example 1;

[0042] Fig.11 This is a high-angle annular dark field imaging image of the nickel-based selenide-supported Pt catalyst corresponding to Comparative Example 2;

[0043] Fig.12 This is the X-ray diffraction pattern of the nickel-based selenide-loaded Pt catalyst corresponding to Comparative Example 4. DETAILED DESCRIPTION

[0044] In order to explain the present invention more clearly, the present invention is further described below in conjunction with embodiments. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0045] As one aspect of the present invention, the present invention provides a nickel-based selenide nano-island confined Pt single-atom catalyst, comprising a carrier and an active center;

[0046] The carrier is a nickel-based selenide nano-island;

[0047] The active center is Pt;

[0048] The Pt metal atoms are confined within the nickel-based selenide nano-islands;

[0049] The Pt metal exists in the form of a single atom.

[0050] As another aspect of the present invention, the method for preparing the nickel-based selenide nano-island confined Pt single-atom catalyst of the present invention comprises the following steps:

[0051] S1: Soaking nickel foam (NF) in a hydrochloric acid solution to remove the oxide layer that may exist on the surface, and then ultrasonically cleaning with deionized water and ethanol to obtain a cleaned nickel foam for standby use;

[0052] S2, mixing and stirring the selenium powder and the reducing agent, and then adding them into deionized water to form a mixed solution;

[0053] S3, transferring the mixed solution and the cleaned nickel foam into a polytetrafluoroethylene-lined autoclave, performing hydrothermal treatment, and vacuum drying after the hydrothermal treatment to obtain a transition metal selenide carrier;

[0054] S4. Use the transition metal selenide carrier as the working electrode, perform electrochemical deposition under alkaline conditions, and obtain the nickel-based selenide nano-island confined Pt single atom catalyst after vacuum drying.

[0055] According to certain embodiments of the present invention, in step 1), the concentration of the hydrochloric acid solution is 1-3M, and the immersion time is 0.3-0.5h.

[0056] According to some embodiments of the present invention, in step 1), the ultrasonic cleaning conditions are: 40%-80% of 400W power, for 0.5-1h.

[0057] According to certain embodiments of the present invention, in step 2), the reducing agent is hydrazine hydrate.

[0058] According to certain embodiments of the present invention, in step 2), the mass / volume ratio of the selenium powder to hydrazine hydrate is 40-100 mg:5 mL; the stirring rate is 800-1200 r / min, and the stirring time is 10-12 h; the mass / volume ratio of the selenium powder to deionized water is 79 mg:20-30 mL.

[0059] According to some embodiments of the present invention, in step 3), the temperature of the hydrothermal treatment is 180-200° C., and the time of the hydrothermal treatment is 8-12 h; the temperature of the vacuum drying is 40-60° C., and the drying time is 12-24 h.

[0060] According to certain embodiments of the present invention, in step 4), the working electrode is a selenide carrier directly grown on nickel foam, the counter electrode is a carbon rod, the reference electrode is Hg / HgO, and the electrolyte is a mixed solution containing a platinum metal precursor and KOH.

[0061] According to some embodiments of the present invention, the mixed solution containing the platinum metal precursor and KOH is a mixed solution obtained by weighing 50-100 mg of potassium chloroplatinate, a platinum metal precursor, and dispersing it in 50-100 mL of 1M KOH electrolyte.

[0062] According to some embodiments of the present invention, in step 4), the electrochemical deposition adopts chronoamperometry, the reversible hydrogen voltage interval applied by the chronoamperometry is [-0.457V, -0.417V], and the deposition time is 300-900s.

[0063] According to some embodiments of the present invention, in step 4), the vacuum drying temperature is 40-60° C., and the drying time is 12-24 hours.

[0064] In this application, the hydrogen evolution performance test of the catalyst electrolysis of water to produce hydrogen includes the following main steps:

[0065] The catalyst Pt1 / NiSe and the substrate material NiSe were cut into 1*2cm 2 The hydrogen evolution performance of the flakes of different sizes was tested in 1M KOH alkaline electrolyte.

[0066] The nickel-based selenide nano-island confined Pt single-atom catalyst obtained by the present invention has excellent application prospects in the electrocatalytic hydrogen evolution reaction.

[0067] Example 1

[0068] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0069] 1) Soak a 2*4cm NF in 3M hydrochloric acid solution for 20 min, then ultrasonically clean it twice with deionized water and ethanol for later use. Accurately weigh 79 mg of Se powder in a clean beaker, transfer 5 mL of N2H4·H2O to the beaker with a pipette, and stir at room temperature and pressure for 12 h at a stirring rate of 1000 r / min;

[0070] 2) After stirring evenly, measure 25mL of deionized water and transfer it to a beaker. Then transfer the mixed solution to a 50mL polytetrafluoroethylene liner, and place the pretreated NF in a hydrothermal kettle and hydrothermal it at 200℃ for 600min. After the reaction is complete, pour out the supernatant of the precursor, pick up the flakes with tweezers, rinse them with deionized water and 99% ethanol several times, and vacuum dry them at 40℃ for 12h. After drying, gray-brown NiSe is obtained;

[0071] 3) Accurately weigh 75 mg of potassium chloroplatinate and dissolve it in 50 mL of 1 M KOH solution as the electrolyte. A standard three-electrode system is used, with nickel selenide grown in situ on the NF substrate as the working electrode, mercuric oxide as the reference electrode, and a carbon rod as the counter electrode for deposition. The deposition voltage is -1.43 V, and the deposition time is 600 s. The obtained sample is dried in a vacuum drying oven at 40 °C for 12 h, which is the Pt single atom catalyst on the nickel selenide nano-islands, denoted as Pt1 / NiSe.

[0072] Hydrogen evolution performance test of water electrolysis :Cut the obtained NiSe and Pt1 / NiSe into 1*2cm 2The electrolysis of water was tested for hydrogen evolution reaction under alkaline conditions of 1M KOH. At the same time, in order to compare with 20% commercial Pt / C, 9mg of commercial Pt / C and 40uL Nafion were dissolved in 1mL V 乙醇 :V 水 =4:1 solution, ultrasonically disperse to form a uniform ink; then drop the ink onto a 1 cm 2 on a clean NF (1*2cm); after drying, it was used as a working electrode for hydrogen evolution test.

[0073] Figure 1 This is the SEM scanning electron microscope image of the nickel-based selenide obtained in this example. It can be seen from the figure that after electrodeposition, the surface block is transformed into an array-like structure, which is more hydrophilic and is conducive to mass transfer, thereby improving the performance of hydrogen evolution by electrolysis of water.

[0074] Figure 2 This is the HAADF-STEM image of the nickel-based selenide obtained in this example. From the image, we can see the small particle size and uniformly dispersed nano-island structure. The atomically dispersed Pt is confined in the nano-islands, which enhances the beneficial effect of anchoring.

[0075] Figure 3 This is the element distribution diagram of the nickel-based selenide obtained in this example. It can be seen from the figure that the Pt atoms are isolated and evenly dispersed on the NiSe carrier without forming clusters.

[0076] Figure 4 This is the XRD spectrum of the nickel-based selenide obtained in this example. Through the analysis of the XRD spectrum, it can be found that the more obvious diffraction peaks all belong to NiSe and Ni3Se2, indicating that the nano-island substrate with a special structure exists in the nickel selenide crystal phase, and no crystal phase diffraction peaks of Pt particles were found after deposition, which is consistent with the conclusion of Pt single atom catalyst obtained from the above analysis.

[0077] Figure 5 This is the overall XPS spectrum of the nickel-based selenide obtained in this example. Analysis shows that Pt, Ni, Se, and O elements are all present in the obtained nickel-based selenide Pt single-atom catalyst.

[0078] Figure 6 This is the XPS energy spectrum of the Pt element. It can be clearly seen that Pt exists in the catalyst in an oxidation state higher than 0 valence, and does not show the Pt metal orbital peak, which also indirectly reflects the absence of Pt metal particles or clusters.

[0079] Figure 7 This is the XPS spectrum of Ni element, Ni 2p 1 / 2 and Ni 2p 3 / 2Accompanied by two corresponding oscillatory satellite peaks. After the electrodeposition of Pt single atoms, the 2P orbital of Ni shifts to the direction of high binding energy, indicating that a strong interaction occurs between Pt and Ni.

[0080] Figure 8 The XPS spectrum of Se element is detailed, Se 3d 5 / 2 and Se 3d 3 / 2 The orbital peaks reveal that Se 2- The main presence of Pt atoms is that the lower but broader peak belongs to Se-O, which is caused by surface oxidation. After electrodeposition, the 3d orbital of Se shifts toward the low binding energy direction, indicating that the incorporation of Pt atoms can effectively change the electron density of NiSe and thus change its electronic structure.

[0081] Fig. 9 This is the XPS energy spectrum of the O element, indicating the presence of OH and OM.

[0082] Fig.10 The linear sweep voltammetry (LSV) curve shows that the electrolysis of nickel-based selenide and Pt / C in 1.0 M KOH in this example shows the hydrogen evolution performance at 10 mA cm -2 At a current density of 1.3 Å, NiSe and Pt1 / NiSe exhibit overpotentials of 175 mV and 107 mV, respectively, and the Tafel slope of Pt1 / NiSe is only 64.32 mV dec. -1 , which is comparable to the commercial Pt / C catalyst, indicating that the Pt single-atom catalyst has excellent hydrogen evolution performance.

[0083] Comparative Example 1

[0084] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0085] Example 1 was repeated, with the only difference being that in step 3), the deposition time required for electrochemical deposition was 250 s.

[0086] After testing, the hydrogen evolution performance in alkaline water electrolysis was slightly poor, the loading amount of Pt single atoms was too low, and a Pt single atom catalyst uniformly distributed on the nano-islands was not obtained.

[0087] It can be seen from this that when the deposition time is too short, it is impossible to obtain a nano-island confined Pt single atom catalyst with regular morphology.

[0088] Comparative Example 2

[0089] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0090] Example 1 was repeated, with the only difference being that in step 3), the deposition time required for electrochemical deposition was 1200 s.

[0091] Fig.11 This is the HAADF-STEM image of the nickel-based selenide-loaded Pt catalyst prepared in this comparative example.

[0092] After testing, it was found that the Pt in this comparative example agglomerated and formed nanoclusters, and was no longer uniformly and dispersedly loaded on the nickel-based selenide nano-islands in the form of single atoms.

[0093] It can be seen that when the deposition time is too long, a uniformly dispersed Pt single atom catalyst cannot be obtained.

[0094] Comparative Example 3

[0095] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0096] Example 1 was repeated, except that in step 3), the mass of potassium chloroplatinite was 25 mg.

[0097] After testing, it was found that the comparative example could not obtain the Pt single atom catalyst supported on the nickel-based selenide carrier.

[0098] It can be seen that when the concentration of the platinum metal precursor is too low, a uniformly dispersed Pt single atom catalyst cannot be obtained.

[0099] Comparative Example 4

[0100] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0101] Example 1 was repeated, except that in step 3), the mass of potassium chloroplatinite was 150 mg.

[0102] Fig.12 This is the XRD spectrum of the nickel-based selenide-supported Pt catalyst prepared in this comparative example.

[0103] After testing, the metal crystal phase peak of the Pt particles can be clearly observed in the XRD diagram, indicating that the Pt in this comparative example has agglomerated to form Pt particles, and is no longer loaded on the nickel-based selenide nano-islands in the form of single atoms.

[0104] It can be seen that when the concentration of the platinum metal precursor is too high, it is impossible to obtain a Pt single atom catalyst uniformly dispersed on the nickel-based selenide nano-islands.

[0105] Comparative Example 5

[0106] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0107] Example 1 was repeated, with the only difference being that in step 1), the mass of selenium powder was 30 mg.

[0108] After testing, it was found that the nickel-based selenide carrier material could not be prepared in this comparative example.

[0109] It can be seen that when the mass concentration of selenium powder is too low, the hydrothermal selenization step cannot be achieved, and nickel-based selenide nano-islands with uniform morphology cannot be obtained.

[0110] Comparative Example 6

[0111] A method for preparing a nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps:

[0112] Example 1 was repeated, with the only difference being that in step 2), the hydrothermal time was 6 h.

[0113] After testing, it was found that the comparative example could not produce a uniformly grown nickel-based selenide carrier.

[0114] It can be seen that when the hydrothermal temperature is too short, the hydrothermal selenization process is not complete, and a nickel-based selenide nano-island structure with uniform morphology and stable growth cannot be obtained.

[0115] To sum up, in the preparation method of the nickel-based selenide nano-island confined Pt single-atom catalyst of the present invention, the ratio of reactants to reducing agents, hydrothermal time, amount of metal precursor, deposition time, etc. are coordinated and cooperated with each other to form a complete technical solution, so that the nickel-based selenide nano-island confined Pt single-atom catalyst required by the present invention can be obtained.

[0116] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A nickel-based selenide nano-island confined Pt single-atom catalyst, comprising a carrier and an active center; characterized in that: The carrier is a nickel-based selenide nano-island; The active center is Pt; The Pt metal atoms are confined within the nickel-based selenide nano-islands; The Pt metal exists in the form of a single atom; The preparation method of the nickel-based selenide nano-island confined Pt single-atom catalyst comprises the following steps: S1: Soak the nickel foam in a hydrochloric acid solution to remove the oxide layer that may exist on the surface, and then use deionized water and ethanol to ultrasonically clean the nickel foam to obtain a cleaned nickel foam for standby use; S2, mixing and stirring the selenium powder and the reducing agent, and then adding them into deionized water to form a mixed solution; the reducing agent is hydrazine hydrate; the mass / volume ratio of the selenium powder to hydrazine hydrate is 40-100 mg:5 mL; the mass / volume ratio of the selenium powder to deionized water is 79 mg:20~30 mL; S3, transferring the mixed solution and the cleaned nickel foam to a polytetrafluoroethylene-lined autoclave, performing hydrothermal treatment, and vacuum drying after the hydrothermal treatment to obtain a transition metal selenide carrier; the hydrothermal treatment temperature is 180-200° C., and the hydrothermal treatment time is 8-12 h; S4. A transition metal selenide carrier is used as a working electrode, and electrochemical deposition is performed under alkaline conditions. After vacuum drying, a nickel-based selenide nano-island confined Pt single-atom catalyst is obtained; the electrolyte is a mixed solution containing a platinum metal precursor and KOH, and the mixed solution containing a platinum metal precursor and KOH is a mixed solution obtained by weighing 50-100 mg of potassium chloroplatinate, a platinum metal precursor, and dispersing it in 50-100 mL of 1M KOH electrolyte; the electrochemical deposition adopts a chronoamperometry, and the reversible hydrogen voltage applied by the chronoamperometry is in the range of [-0.457V, -0.417V], and the deposition time is 300-900s.

2. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S1, the concentration of the hydrochloric acid solution is 1-3 M, and the soaking time is 0.3-0.5 h.

3. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S1, the ultrasonic cleaning conditions are: at 40%-80% of 400 W power, for 0.5-1 h.

4. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S2, the stirring rate is 800-1200 r / min, and the stirring time is 10-12 h.

5. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S3, the vacuum drying temperature is 40-60°C, and the drying time is 12-24h.

6. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S4, the working electrode is a selenide carrier directly grown on nickel foam, the counter electrode is a carbon rod, and the reference electrode is Hg / HgO.

7. The nickel-based selenide nano-island confined Pt single-atom catalyst according to claim 1, characterized in that: In step S4, the vacuum drying temperature is 40-60° C., and the drying time is 12-24 hours.

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