Purple phosphorus-based monatomic catalyst for efficient hydrogen evolution and preparation method of purple phosphorus-based monatomic catalyst

Abstract

The invention discloses a purple phosphorus-based monatomic catalyst for efficient hydrogen evolution and a preparation method of the purple phosphorus-based monatomic catalyst, and belongs to the technical field of catalysts. The preparation method comprises the following steps: treating block purple phosphorus by a liquid-phase ultrasonic stripping method to obtain a purple phosphorus precursor serving as a carrier; mixing a platinum salt solution with the purple phosphorus precursor to form a mixed solution; and carrying out irradiation treatment on the mixed solution by adopting a standard solar spectrum, so that platinum ions in the platinum salt are reduced and anchored on the purple phosphorus precursor in a monatomic form, thereby obtaining the purple phosphorus-based monatomic catalyst. The whole technological process only relates to common raw materials such as purple phosphorus and trace platinum salt, operation is easy and convenient, cost is low, and product purity is high. According to the method, the monatomic catalyst with a clear structure is successfully constructed through ingenious process design by utilizing the confinement effect of purple phosphorus and the synergistic effect of photoreduction, and a solid foundation is laid for the monatomic catalyst to show high catalytic activity and excellent stability in a hydrogen evolution reaction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of resistance alloy manufacturing, and particularly relates to a violet phosphorus-based monatomic catalyst for efficient hydrogen evolution and a preparation method thereof. BACKGROUND

[0002] The development of clean and efficient renewable energy is of great significance for reducing carbon emissions and achieving sustainable development. Although technologies such as solar energy, wind energy, geothermal energy, and biomass energy have made some progress, they are still limited by low energy density, strong intermittency, and geographical dependence, making it difficult to meet the demand for continuous and stable energy supply. Hydrogen energy is considered as an ideal energy carrier due to its high energy density and zero emission characteristics. Electrochemical water splitting, especially the hydrogen evolution reaction (HER), is an effective way to obtain high-purity hydrogen. However, this process highly depends on efficient catalysts to reduce the reaction overpotential and improve energy conversion efficiency. Although the widely used platinum-based catalysts have excellent catalytic activity, their high cost, limited reserves, and problems such as aggregation, dissolution, or deactivation during the catalytic process seriously restrict their large-scale application. Therefore, developing new electrocatalysts with high activity, high stability, and low cost has become a key challenge in current research.

[0003] Research has found that violet phosphorus (VP) as a phosphorus allotrope with a unique cross-tubular double-layer structure shows good application prospects. The monoclinic crystal is composed of two layers of perpendicular tubular phosphorus chains stacked by van der Waals force, with an interlayer spacing of about 11 Å. The single layer is a wrinkled phosphorus atom net with a thickness of about 3.6 Å. The P atoms in the layer form a distorted tetrahedron with a bond length of 2.22-2.24 Å through sp 3 hybridization, forming a five / six-hexagon alternating honeycomb-like topology. This structure produces a 7.0 Å periodic fluctuation (amplitude 1.8 Å) along the normal direction, forming two non-equivalent sites of convex and concave, which induces double-layer AB-type misalignment, so that the convex atoms in the upper layer are directly opposite to the concave cavities in the lower layer, maximizing van der Waals attraction and minimizing Coulomb repulsion. This structure not only gives violet phosphorus a higher specific surface area and adjustable electronic structure, but also improves the environmental stability of the material due to its self-passivation boundary characteristics. The interlayer slip and wrinkle unfolding behavior further bring about a direct band gap adjustable window of about 0.7 eV, making it show unique advantages in the field of catalysis and energy compared to other materials such as black phosphorus.

[0004] Although platinum metal as a HER catalyst has near-thermal neutral low hydrogen adsorption free energy (|ΔGH*|≈0.0071eV) and low overpotential, the problems of high cost and low atomic utilization of nitrogen have not been effectively solved, therefore, it is urgent to develop new supports and synthesis strategies to maximize the dispersion and stability of platinum atoms and fully exert their intrinsic catalytic activity. SUMMARY

[0005] To overcome the shortcomings of existing platinum-based hydrogen evolution catalysts, such as high cost, low atom utilization, and insufficient stability, the present invention aims to provide a purple phosphorus-based single-atom catalyst for efficient hydrogen evolution and its preparation method. This catalyst can reduce the amount of precious metals used while fully utilizing the unique support characteristics of purple phosphorus to achieve efficient dispersion and stable anchoring of platinum atoms, thereby improving the atom utilization, hydrogen evolution reaction activity, and long-term stability of the catalyst.

[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for preparing a highly efficient phosphorus-based single-atom catalyst for hydrogen evolution, comprising the following steps: Step 1: The bulk purple phosphorus is treated by liquid phase ultrasonic exfoliation to obtain the purple phosphorus precursor, which is used as a carrier. Step 2: Mix the platinum salt solution with the purple phosphorus precursor to form a mixture; Step 3: Irradiate the mixture using a standard solar spectrum to reduce platinum ions in the platinum salt and anchor them to the purple phosphorus precursor in single-atom form, thereby obtaining a purple phosphorus-based single-atom catalyst.

[0007] A further improvement of this invention is that the specific method for preparing the purple phosphorus precursor is as follows: the bulk purple phosphorus is thoroughly ground in an agate mortar and then dispersed in a solvent, ultrasonically treated in an ultrasonic bath, and then centrifuged at 5000~8000 rpm / min for 2~8 min to obtain the supernatant, which is denoted as solution A; wherein the ultrasonic power is 50~200W, the ultrasonic time is 20~30 hours, and the temperature is kept below 5℃ during the ultrasonic process.

[0008] A further improvement of the present invention is that the solvent is anhydrous ethanol, and the mass-to-volume ratio of bulk purple phosphorus to solvent is 1~1.5:2 (mg / mL).

[0009] A further improvement of the present invention is that the specific method for forming the mixture is as follows: weigh an appropriate amount of platinum salt and dissolve it in anhydrous ethanol, denoted as solution B, add solution B dropwise to solution A, and stir at room temperature for 20-40 minutes to obtain the mixture; wherein the concentration of platinum salt dissolved in anhydrous ethanol is 0.2-0.8 mg / mL.

[0010] A further improvement of the present invention is that the platinum salt is chloroplatinic acid.

[0011] A further improvement of the present invention is that the mass ratio of the platinum salt to the purple phosphorus precursor is 1:10 to 1:2.5.

[0012] A further improvement of this invention is that the irradiation treatment is carried out under stirring conditions, the irradiation time is 20-120 min, and the irradiation intensity is 80-150 mW / cm². -2 .

[0013] A further improvement of the present invention is that the irradiation treatment further includes separation, washing and drying steps, specifically: the irradiated mixture is centrifuged at 10000~15000 rpm / min for 5~15 min, washed with anhydrous ethanol 3~5 times, and then dried in a vacuum drying oven at 50~100℃ for 5~10 hours.

[0014] Secondly, the present invention also provides a purple phosphorus-based single-atom catalyst for efficient hydrogen evolution, which is prepared by the above-described preparation method.

[0015] A further improvement of the present invention is that the catalyst comprises a purple phosphorus precursor and platinum single atoms anchored thereon, wherein the loading of platinum single atoms is 5% to 25%.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing a purple phosphorus-based single-atom catalyst for efficient hydrogen evolution reaction. The method first processes bulk purple phosphorus using a liquid-phase ultrasonic exfoliation method, successfully preparing a purple phosphorus nanosheet support with a unique bilayer structure and a large specific surface area, providing an ideal substrate for the subsequent efficient loading of metal atoms. Subsequently, a platinum salt solution is mixed with this support, and the mixture is irradiated using a standard solar spectrum, achieving green, mild reduction and precise anchoring of platinum ions. This photochemical reduction process does not require strong reducing agents or high-temperature heat treatment, resulting in mild conditions, low energy consumption, and effectively avoiding the migration and aggregation of metal atoms. This ensures that platinum is highly uniformly dispersed on the purple phosphorus support in single-atom form, thereby maximizing the exposure of active sites. The entire process involves only common raw materials such as purple phosphorus and trace amounts of platinum salt, making it simple to operate, low in cost, and producing high-purity products. Through ingenious process design, this method utilizes the confinement effect of purple phosphorus and the synergistic effect of photoreduction to successfully construct a structurally well-defined single-atom catalyst, laying a solid foundation for its high catalytic activity and excellent stability in the hydrogen evolution reaction.

[0017] This invention also provides a purple phosphorus-based single-atom catalyst for efficient hydrogen evolution reaction. In this catalyst, platinum atoms are highly dispersed and stably anchored on a unique purple phosphorus support at single sites, exhibiting extremely high intrinsic activity in the hydrogen evolution reaction. It can significantly reduce the reaction overpotential and has strong conductivity, multiple active sites, and good electrocatalytic performance. At the same time, the strong interaction between platinum and the purple phosphorus support ensures the long-term stability of the catalyst under harsh reaction conditions. Attached Figure Description

[0018] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components of the invention.

[0019] Figure 1 This is a schematic diagram of a method for preparing a highly efficient purple phosphorus-based single-atom catalyst for hydrogen evolution, provided in an embodiment of the present invention. Figure 2 This is a transmission electron microscope (TEM) image of the Pt / VP material prepared in Example 1 of the present invention; Figure 3 The image shows the X-ray diffraction energy spectrum (XRD) analysis of the Pt / VP material prepared in Example 1 of this invention. Figure 4 The HER linear scan voltammetry curve of Pt / VP prepared in Example 1 of this invention, at a scan rate of 5 mV / s in 1.0 mol / L potassium hydroxide electrolyte; Figure 5 The HER linear scan voltammetry curves of Pt / VP prepared in Examples 2 to 5 of this invention, at a scan rate of 5 mV / s, in a potassium hydroxide electrolyte of 1.0 mol / L. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] like Figure 1 As shown, this invention provides a method for preparing a highly efficient purple phosphorus-based single-atom catalyst for hydrogen evolution, comprising the following steps: Step 1: The bulk purple phosphorus is treated by liquid phase ultrasonic exfoliation to obtain the purple phosphorus precursor; First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 20-30 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 20-30 h at an ultrasonic power of 50-200 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, the mixture is centrifuged at 5000-8000 rpm / min for 2-8 min. The supernatant is collected and designated as solution A for later use.

[0026] S2: Mix the platinum salt solution with the purple phosphorus precursor to form a mixture; Weigh 3-9 mg of platinum salt and dissolve it in 5-15 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 20-40 min to form a mixture.

[0027] S3: The mixture is irradiated with a standard solar spectrum to reduce the platinum ions in the platinum salt and anchor them on the purple phosphorus precursor in the form of single atoms, thus obtaining a purple phosphorus-based single-atom catalyst. The above mixture was subjected to the AM1.5G standard solar spectrum (80~150mW / cm²). -2 While stirring, irradiate for 20-120 min. Centrifuge the resulting suspension at 10000-15000 rpm / min for 5-15 min. Wash with anhydrous ethanol 3-5 times. Then place the precipitate in a vacuum drying oven at 50-100℃ and dry at a constant temperature for 5-10 h to obtain the purple phosphorus-based single-atom catalyst, denoted as Pt / VP-SAC.

[0028] In some embodiments, the mass-to-volume ratio of bulk purple phosphorus to solvent is 1~1.5:2 (mg / mL).

[0029] In some embodiments, the concentration of platinum salt dissolved in anhydrous ethanol is 0.2~0.8 mg / mL; preferably, the mass ratio of platinum salt to anhydrous ethanol is 1:780.

[0030] In some embodiments, the platinum salt is chloroplatinic acid (H2Cl6Pt), and the mass ratio of the platinum salt to the purple phosphorus precursor is 1:10 to 1:2.5.

[0031] This invention uses purple phosphorus as the substrate material and, by introducing a very small amount of the noble metal platinum (Pt) and precisely controlling key parameters such as the photoirradiation reaction time and raw material ratio, successfully achieved effective control over the loading of platinum single atoms, thus preparing a well-defined purple phosphorus-based platinum single-atom catalyst. This preparation method not only features low raw material cost, simple process, and low reaction energy consumption, possessing the potential for large-scale production, but also fully utilizes the unique bilayer structure of purple phosphorus to spatially confine platinum single atoms, effectively inhibiting metal atom aggregation and fully exposing the active sites. This structural advantage significantly improves the catalyst's reactivity, lowers the hydrogen evolution reaction energy barrier, and enables it to exhibit excellent electrocatalytic characteristics when applied to the hydrogen evolution reaction.

[0032] The present invention also provides a purple phosphorus-based single-atom catalyst for efficient hydrogen evolution prepared by the above preparation method, comprising a purple phosphorus precursor and platinum single atoms anchored thereon, wherein the loading of platinum single atoms is 5% to 25%. This catalyst retains the unique bilayer structure and large specific surface area of ​​purple phosphorus, and has uniformly dispersed metallic platinum single atoms, thus fully exposing the active sites of the catalyst.

[0033] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0034] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0035] Example 1 This embodiment provides a method for preparing a purple phosphorus-based single-atom catalyst Pt / VP-SAC for efficient hydrogen evolution, including the following steps: Step 1: First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 20 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 24 h at an ultrasonic power of 100 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, it is centrifuged at 6000 rpm / min for 5 min. The supernatant is collected and labeled as solution A for later use.

[0036] S2: Weigh 3 mg of H2Cl6Pt and dissolve it in 10 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 30 min to form a mixture.

[0037] S3: Expose the above mixture to the AM1.5G standard solar spectrum (100mW cm⁻¹). -2 The mixture was stirred and irradiated for 20 minutes. The resulting suspension was centrifuged at 13,000 rpm for 10 minutes and washed four times with anhydrous ethanol. The precipitate was then placed in a vacuum drying oven at 80°C and dried at a constant temperature for 8 hours to obtain a purple phosphorus-based single-atom catalyst, denoted as Pt / VP-SAC.

[0038] Figure 2 These are aberration-corrected transmission electron microscopy (ACTEM) images and energy-dispersive X-ray spectroscopy (EDS) results of the Pt / VP-SAC material prepared in Example 1 of this invention. Figure 2 It can be seen that the surface of the Pt / VP-SAC sample is basically smooth, with no platinum agglomeration. High-resolution images clearly show platinum uniformly distributed as single atoms on the surface of the purple phosphorus material. EDS spectra also show that Pt is uniformly loaded on the purple phosphorus surface. Figure 3 This is the X-ray diffraction (XRD) spectrum analysis of the Pt / VP-SAC material prepared in Example 1 of this invention and purple phosphorus. From... Figure 3 It can be seen that the three strong diffraction peaks in the XRD energy spectrum of the VP sample correspond to the (004), (006), and (008) crystal planes of purple phosphorus, respectively. The diffraction peak positions of the Pt / VP sample are almost completely shifted relative to VP, which suggests that there is no platinum oxide or other crystalline form in the Pt / VP sample. Combined with the lens image and EDS results, it can be confirmed that platinum is loaded on the purple phosphorus substrate in the form of single atoms.

[0039] When the Pt / VP-SAC catalyst prepared in this invention is used as a catalyst for water electrolysis, the specific steps are as follows: the prepared Pt / VP-SAC catalyst material is loaded onto a glassy carbon electrode as the working electrode, a saturated calomel electrode is used as the reference electrode, and a carbon rod is used as the counter electrode. Its HER electrochemical performance is tested in a 1.0 mol / L KOH solution at room temperature and pressure.

[0040] Figure 4 The HER linear sweep voltammetry curve of the Pt / VP-SAC material prepared in Example 1 of this invention, scanned at a rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte, is shown below. The current density is 10 mA / cm². –2 At that time, the overpotential of RuCo@NC was 37mV. In practical applications, the ultimate goal of electrocatalytic water splitting for hydrogen production is to reduce costs and increase efficiency. In this embodiment, the unique bilayer structure of purple phosphorus confines the noble metal platinum single atoms, allowing them to be uniformly dispersed on the purple phosphorus substrate in the form of single atoms. This achieves excellent catalytic performance while significantly reducing costs.

[0041] Example 2 This embodiment provides a method for preparing a purple phosphorus-based single-atom catalyst Pt / VP-SAC for efficient hydrogen evolution, including the following steps: Step 1: First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 25 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 20 h at an ultrasonic power of 200 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, it is centrifuged at 5000 rpm / min for 8 min. The supernatant is taken and recorded as solution A for later use.

[0042] Step 2: Weigh 5 mg of H2Cl6Pt and dissolve it in 15 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 40 min to form a mixture.

[0043] Step 3: Expose the above mixture to the AM1.5G standard solar spectrum (80mW cm⁻¹). -2 The mixture was stirred and irradiated for 60 min. The resulting suspension was centrifuged at 15000 rpm for 5 min, washed three times with anhydrous ethanol, and then the precipitate was placed in a vacuum drying oven at 50℃ and dried at a constant temperature for 10 h to obtain a purple phosphorus-based single-atom catalyst, denoted as Pt / VP-2.

[0044] like Figure 5 As shown, the HER linear sweep voltammetry curve of the Pt / VP-2 material prepared in this embodiment, scanned at a rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte, is obtained when the current density is 10 mA / cm². –2 At that time, the overpotential of the Pt / VP-2 single-atom catalyst was 38 mV.

[0045] Example 3 This embodiment provides a method for preparing a purple phosphorus-based single-atom catalyst Pt / VP-SAC for efficient hydrogen evolution, including the following steps: Step 1: First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 30 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 30 h at an ultrasonic power of 50 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, it is centrifuged at 8000 rpm / min for 2 min. The supernatant is taken and recorded as solution A for later use.

[0046] Step 2: Weigh 6 mg of H2Cl6Pt and dissolve it in 5 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 20 min to form a mixture.

[0047] Step 3: Expose the above mixture to the AM1.5G standard solar spectrum (150mW cm⁻¹). -2 While stirring, the mixture was irradiated for 30 minutes. The resulting suspension was centrifuged at 10,000 rpm for 15 minutes and washed five times with anhydrous ethanol. The precipitate was then placed in a vacuum drying oven at 100°C and dried at a constant temperature for 5 hours to obtain a purple phosphorus-based single-atom catalyst, denoted as Pt / VP-3.

[0048] like Figure 5 As shown, the HER linear sweep voltammetry curve of the Pt / VP-3 material prepared in this embodiment, scanned at a rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte, is obtained when the current density is 10 mA / cm². –2 At that time, the overpotential of the Pt / VP-3 single-atom catalyst was 52 mV.

[0049] Example 4 This embodiment provides a method for preparing a purple phosphorus-based single-atom catalyst Pt / VP-SAC for efficient hydrogen evolution, including the following steps: Step 1: First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 22 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 25 h at an ultrasonic power of 100 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, it is centrifuged at 6000 rpm / min for 5 min. The supernatant is collected and recorded as solution A for later use.

[0050] Step 2: Weigh 9 mg of H2Cl6Pt and dissolve it in 5 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 40 min to form a mixture.

[0051] Step 3: Expose the above mixture to the AM1.5G standard solar spectrum (100mW cm⁻¹). -2The mixture was stirred and irradiated for 120 min. The resulting suspension was centrifuged at 13000 rpm / min for 10 min, washed 4 times with anhydrous ethanol, and then the precipitate was placed in a vacuum drying oven at 80℃ and dried at a constant temperature for 8 h to obtain a purple phosphorus-based single-atom catalyst, denoted as Pt / VP-4.

[0052] like Figure 5 As shown, the HER linear sweep voltammetry curve of the Pt / VP-4 material prepared in this embodiment, scanned at a rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte, is obtained when the current density is 10 mA / cm². –2 At that time, the overpotential of the Pt / VP-4 single-atom catalyst was 40 mV.

[0053] Example 5 This embodiment provides a method for preparing a purple phosphorus-based single-atom catalyst Pt / VP-SAC for efficient hydrogen evolution, including the following steps: Step 1: First, the bulk purple phosphorus synthesized by CVT is thoroughly ground in an agate mortar. Then, 28 mg of the ground powdered VP is weighed and dispersed in 40 mL of anhydrous ethanol. The mixture is ultrasonicated in an ultrasonic bath for 28 h at an ultrasonic power of 50 W. During the entire ultrasonication process, the temperature of the liquid is kept below 5 °C. Then, it is centrifuged at 8000 rpm / min for 2 min. The supernatant is taken and recorded as solution A for later use.

[0054] Step 2: Weigh 8 mg of H2Cl6Pt and dissolve it in 10 mL of anhydrous ethanol, which is recorded as solution B. Add solution B dropwise to solution A and stir at room temperature for 20 min to form a mixture.

[0055] Step 3: Expose the above mixture to the AM1.5G standard solar spectrum (120mW cm⁻¹). -2 The mixture was stirred and irradiated for 40 minutes. The resulting suspension was centrifuged at 10,000 rpm for 5 minutes and washed 5 times with anhydrous ethanol. The precipitate was then placed in a vacuum drying oven at 100°C and dried at a constant temperature for 5 hours to obtain a purple phosphorus-based single-atom catalyst, denoted as Pt / VP-5.

[0056] like Figure 5 As shown, the HER linear sweep voltammetry curve of the Pt / VP-5 material prepared in this embodiment, scanned at a rate of 5 mV / s in a 1.0 mol / L potassium hydroxide electrolyte, is shown when the current density is 10 mA / cm². –2 At that time, the overpotential of the Pt / VP-5 single-atom catalyst was 60 mV.

[0057] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a purple phosphorus-based monatomic catalyst for efficient hydrogen evolution, characterized in that, The method comprises the following steps: Step 1, treating bulk purple phosphorus by liquid-phase ultrasonic exfoliation to obtain a purple phosphorus precursor as a carrier; Step 2, mixing a platinum salt solution with the purple phosphorus precursor to form a mixed solution; Step 3, irradiating the mixed solution with a standard solar spectrum to reduce platinum ions in the platinum salt and anchor the platinum ions on the purple phosphorus precursor in the form of single atoms to obtain a purple phosphorus-based single-atom catalyst.

2. The method according to claim 1, wherein, The specific method for preparing the purple phosphorus precursor is: grinding the bulk purple phosphorus in a corundum mortar body, dispersing it in a solvent, ultrasonically treating it in an ultrasonic bath, and then centrifuging it at a speed of 5000-8000 rpm / min for 2-8 min to obtain a supernatant, denoted as solution A; wherein the ultrasonic power is 50-200 W, the ultrasonic time is 20-30 hours, and the temperature during the ultrasonic process is kept below 5℃.

3. The method according to claim 2, wherein, The solvent is anhydrous ethanol, and the mass-volume ratio of the bulk purple phosphorus to the solvent is 1-1.5:2 (mg / mL).

4. The method according to claim 1 or 2, wherein, The specific method for forming the mixed solution is: weighing an appropriate amount of platinum salt, dissolving it in anhydrous ethanol to obtain solution B, and then dropping solution B into solution A, stirring at room temperature for 20-40 min to obtain the mixed solution; wherein the concentration of the platinum salt dissolved in anhydrous ethanol is 0.2-0.8 mg / mL.

5. The method of claim 4, wherein the method is characterized by: The platinum salt is chloroplatinic acid.

6. The method of claim 1, wherein the method is characterized by: The mass ratio of the platinum salt to the purple phosphorus precursor is 1:10-1:2.

5.

7. The method of claim 1, wherein the method is characterized by: The irradiation treatment is carried out under stirring for 20-120 min at an irradiation intensity of 80-150 mW / cm -2 .

8. The method of claim 1, wherein the method is characterized by: After the irradiation treatment, the method further comprises the steps of separation, washing and drying, specifically: centrifuging the irradiated mixed solution at a speed of 10000-15000 rpm / min for 5-15 min, washing it with anhydrous ethanol for 3-5 times, and then drying it in a vacuum drying oven at 50-100℃ for 5-10 hours.

9. A purple phosphorus-based single-atom catalyst for efficient hydrogen evolution, characterized in that, The catalyst comprises a purple phosphorus precursor and platinum single atoms anchored thereon, wherein the loading amount of the platinum single atoms is 5%-25%.

10. The monatomic catalyst according to claim 9, wherein, The catalyst comprises a purple phosphorus precursor and platinum single atoms anchored thereon, wherein the loading amount of the platinum single atoms is 5%-25%.

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