A composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms and a preparation method and application thereof
By growing platinum single atoms in situ on the surface of cadmium sulfide and forming a uniformly distributed composite catalyst through chemical bonding, the problem of low platinum atom utilization is solved, the photocatalytic hydrogen evolution activity and stability of the catalyst are improved, and the cost is reduced.
Patent Information
- Application Number
- CN202311631908.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-30
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2043-11-30
AI Technical Summary
In existing technologies, low platinum atom utilization leads to high catalyst costs and reduced reaction activity. Furthermore, the weak interaction between cadmium sulfide and platinum particles reduces the efficiency of photogenerated carrier transfer.
By growing platinum single atoms in situ on the surface of cadmium sulfide and loading them with chemical bonds, a uniformly distributed composite catalyst is formed, which improves the migration efficiency of photogenerated electrons and the utilization rate of active sites.
This achieved 100% utilization of platinum atoms, improved the photocatalytic hydrogen evolution activity and stability of the catalyst, lowered the reaction energy barrier, and enhanced the economics and industrial application potential of the catalyst.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of photocatalytic hydrogen evolution, and particularly relates to a composite catalyst with cadmium sulfide surface loaded with platinum monatomic atoms and a preparation method and application thereof. BACKGROUND
[0002] Photocatalysis is a reaction process of converting the energy of sunlight into chemical energy. Sunlight is a green and sustainable energy, and its conversion and utilization are very promising. At present, the main reaction types of photocatalysis include hydrogen evolution, carbon dioxide reduction, ammonia synthesis, and pollutant degradation. Cadmium sulfide is an inorganic semiconductor material, which has a suitable visible light response range (band gap of 2.4 eV), and thus has a wide application in the field of photocatalysis. However, in the process of photocatalysis, the low utilization rate of photo-generated electrons reduces the catalytic activity. At the same time, when the photo-generated carriers cannot be consumed in time, the photo-corrosion effect will be intensified, thereby causing the deactivation of the catalyst.
[0003] At present, in view of this phenomenon, researchers have synthesized a variety of cocatalysts through compounding, such as noble metal nanoparticles, transition metal phosphide nanoparticles, etc. Platinum active sites are used for hydrogen evolution reaction, which has the advantages of low activation energy and desorption energy, making it a good hydrogen evolution active site. However, the utilization rate of platinum atoms has a great influence on the cost of the catalyst. High platinum atom utilization rate can effectively utilize the platinum atoms in the system, so that less platinum atoms exhibit higher hydrogen evolution activity. However, the size of ordinary platinum nanoparticles is usually more than 5 nm. According to the calculation, when the particle size is 2 nm, the utilization rate of atoms is less than 20%. At present, the common platinum cocatalyst loading is to load platinum nanoparticles into the catalyst system by photodeposition. On the one hand, the method obtained is platinum nanoparticles, and the particle size is generally about 5 nm. On the other hand, the catalyst prepared by this method has a weak interaction force between cadmium sulfide and platinum particles, which reduces the transfer efficiency of photo-generated carriers, thereby reducing the utilization of light. At the same time, the low atom utilization rate leads to high cost of the catalyst and low reaction activity. SUMMARY
[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a composite catalyst with cadmium sulfide surface loaded with platinum monatomic atoms and a preparation method and application thereof, which can solve the technical problems of low platinum atom utilization rate, high cost of catalyst, and low reaction activity in the prior art.
[0005] In order to achieve the above-mentioned purpose, the technical scheme is adopted as follows:
[0006] The application discloses a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, which takes cadmium sulfide particles as a substrate, in-situ grows platinum atom active sites on the surface of the substrate, and loads the platinum monatomic atoms on the surface of the cadmium sulfide through a chemical bond.
[0007] Preferably, the platinum monatomic atoms are uniformly distributed on the surface of the cadmium sulfide.
[0008] Preferably, the cadmium sulfide particles are spherical particles with a size of 20-50 nm.
[0009] Preferably, the specific surface area of the cadmium sulfide particles is 30-60 m 2 / g.
[0010] Further preferably, the specific surface area of the cadmium sulfide particles is 55 m 2 / g.
[0011] The application further discloses a preparation method of the composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms.
[0012] Preferably, the mass ratio of the cadmium sulfide to the TCPP(Pt) is 20-40:4.
[0013] Further preferably, the mass ratio of the cadmium sulfide to the TCPP(Pt) is 20:4.
[0014] Preferably, the cadmium sulfide and the TCPP(Pt) are ultrasonically treated in a mixed solution of N,N-dimethylformamide and ethanol at a power of 100 W for 30 minutes to fully mix the materials.
[0015] Preferably, the in-situ growth is a solvothermal reaction at 65-90 DEG C for 12-24 h.
[0016] Further preferably, the in-situ growth is a solvothermal reaction at 85 DEG C for 24 h.
[0017] Preferably, the preparation method of the composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms comprises the following steps.
[0018] Step 1, cadmium nitrate and sodium sulfide are put into water, reacted at 150-180 DEG C for 6-12 h, fully washed with water and ethanol, and vacuum dried at 50-60 DEG C overnight to prepare cadmium sulfide;
[0019] Step 2, after ultrasonic treatment for 30 minutes in a mixed solution of N,N-dimethylformamide and ethanol, the cadmium sulfide, TCPP (Pt) and pyrazine are subjected to a solvothermal reaction at 65-90 DEG C for 12-24 hours, and the product is obtained after centrifugation; wherein the amount ratio of cadmium sulfide, TCPP (Pt), pyrazine, N,N-dimethylformamide and ethanol is (20-40) mg:4 mg:0.8 mg:12 mL:3 mL;
[0020] Step 3, the product obtained in Step 2 is dried to obtain a composite catalyst of cadmium sulfide surface loaded with platinum single atoms.
[0021] Further preferably, the above preparation method comprises the following steps:
[0022] Step 1, cadmium nitrate and sodium sulfide are put into water, reacted at 180 DEG C for 12 hours, washed with water and ethanol, and vacuum dried at 60 DEG C overnight to obtain cadmium sulfide;
[0023] Step 2, after ultrasonic treatment for 30 minutes in a mixed solution of N,N-dimethylformamide and ethanol, the cadmium sulfide, TCPP (Pt) and pyrazine are subjected to a solvothermal reaction at 85 DEG C for 24 hours, and the product is obtained after centrifugation; wherein the amount ratio of cadmium sulfide, TCPP (Pt), pyrazine, N,N-dimethylformamide and ethanol is 20 mg:4 mg:0.8 mg:12 mL:3 mL;
[0024] Step 3, the product obtained in Step 2 is dried to obtain a composite catalyst of cadmium sulfide surface loaded with platinum single atoms.
[0025] The application also discloses application of the composite catalyst of cadmium sulfide surface loaded with platinum single atoms in photocatalytic hydrogen evolution.
[0026] Compared with the prior art, the application has the following beneficial effects:
[0027] The composite catalyst of cadmium sulfide surface loaded with platinum single atoms disclosed by the application loads the active sites of platinum single atoms on the surface of cadmium sulfide in a chemical bond mode, improves the interaction between photoactive substances and single-atom active sites, is favorable for the migration of photo-generated electrons from cadmium sulfide to the active sites, and greatly improves the utilization rate of the active sites due to the single-atom dispersed platinum single atoms.
[0028] Further, the platinum single atoms are uniformly distributed on the cadmium sulfide surface, and the uniformly dispersed single atom sites can enable sufficient contact between the cadmium sulfide and ligands, thereby improving the light-generated electron transfer efficiency. In photocatalysis, the light-generated electrons need to be transferred to the active sites in time, otherwise, the recombination of the light-generated electron-hole pairs will occur, the light-generated electrons will be deactivated, and the catalytic efficiency and light energy utilization rate are reduced.
[0029] Further, the active substance connected by the chemical bond and the single atom site have strong interaction force, which is beneficial to recycling of the catalyst.
[0030] The preparation method of the composite catalyst disclosed in the application selects cadmium sulfide as the semiconductor, which is cheap and easy to prepare, and the preparation process of loading single atom platinum on the surface of cadmium sulfide is simple and easy to industrialized production. Meanwhile, under laboratory conditions and sunlight conditions, the composite catalyst exhibits high photocatalytic hydrogen evolution activity, which provides a thought for industrial application. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 It is a molecular structure simulation diagram of cadmium sulfide;
[0032] Figure 2 It is a structure simulation diagram of TCPP (Pt);
[0033] Figure 3 It is a scatter plot of the specific surface area of cadmium sulfide calculated by the multipoint method;
[0034] Figure 4 It is an SEM diagram of cadmium sulfide prepared in Example 1 of the application;
[0035] Figure 5 It is an SEM diagram of the composite catalyst prepared in Example 1 of the application;
[0036] Figure 6 It is an EDX mapping diagram of the composite catalyst prepared in Example 1 of the application;
[0037] Figure 7 It is a PXRD diagram of cadmium sulfide prepared in Example 1 of the application;
[0038] Figure 8 It is an ultraviolet-visible absorption spectrum of cadmium sulfide and the composite catalyst prepared in Example 1 of the application;
[0039] Figure 9 It is an XPS diagram of cadmium sulfide and the composite catalyst prepared in Example 1 of the application;
[0040] Figure 10 It is a catalytic activity comparison columnar diagram of cadmium sulfide prepared in Example 1 of the application;
[0041] Figure 11 Catalytic activity column chart of five comparative examples;
[0042] Figure 12 PXRD contrast chart before and after catalysis;
[0043] Figure 13 Contrast chart of activity results under sunlight;
[0044] Figure 14 Theoretical calculation chart of photocatalytic hydrogen evolution;
[0045] Figure 15 Reaction path mechanism explanation chart in the catalytic process. DETAILED DESCRIPTION
[0046] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.
[0047] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0048] The present application will be described in further detail below in conjunction with the accompanying drawings:
[0049] Example 1
[0050] A preparation method of a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0051] 1) 832.9 milligrams of cadmium nitrate tetrahydrate and 648.5 milligrams of sodium sulfide nonahydrate are added to 50 milliliters of water, and reacted at 180°C for 12 hours to obtain cadmium sulfide powder.
[0052] 2) The cadmium sulfide powder was thoroughly washed with water and ethanol, and then vacuum-dried at 50° C. overnight to obtain dry cadmium sulfide powder.
[0053] 3) 20 mg of cadmium sulfide powder, 0.8 mg of pyrazine, and 4 mg of TCPP(Pt) were placed in a mixed solvent of 12 ml of N,N-dimethylformamide and 3 ml of ethanol. After ultrasonication for 30 minutes, the mixture was reacted at 85°C for 1 day, and the product was obtained after centrifugation.
[0054] 4) The product of step 3) was washed with water and ethanol, placed in a vacuum drying oven, and vacuum dried at 50° C. overnight (yield 95%) to obtain the target product, a composite catalyst with platinum single atoms loaded on the surface of cadmium sulfide.
[0055] like Figure 1 As shown, cadmium sulfide is P 63mc space group, Figure 2 The platinum atom is shown to be chelated by four surrounding single atoms.
[0056] like Figure 3 and 4 As shown, cadmium sulfide is a nanoparticle of 20-50 nm. The specific surface area is 55 m 2 / g. The small size of cadmium sulfide particles improves the utilization of atoms and provides more sites for interaction with platinum active sites.
[0057] like Figure 5 and 6 As shown, in the composite catalyst, platinum atoms are evenly dispersed around the catalyst, proving that the material can effectively disperse platinum active sites.
[0058] like Figure 7 As shown, cadmium sulfide has three obvious PXRD peaks at 25.6, 26.9 and 29.0°, proving that the structure of cadmium sulfide itself has not changed after synthesis.
[0059] like Figure 8 As shown in the figure, the band gap of cadmium sulfide is 2.4eV. This shows that cadmium sulfide has good photoresponse ability in the visible light range and can provide efficient photogenerated electron-hole pairs.
[0060] like Figure 9 As shown, each element has a corresponding binding energy in the XPS spectrum, proving that the target composite catalyst was successfully synthesized.
[0061] Comparative Example 1
[0062] The difference from Example 1 is that the cadmium sulfide particles were prepared using the method (stirring at 80° C. for 2 hours).
[0063] A method for preparing a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0064] 1) 714.5 mg of cadmium acetate dihydrate and 205.4 mg of thioacetamide (TAA) were added to 200 mL of ethanol, and after ultrasonic treatment for 10 minutes, stirring was carried out at 80°C for 2 hours to obtain a yellowish cadmium sulfide powder. The cadmium sulfide powder was washed with water and ethanol, and then vacuum dried at 50°C overnight (yield 85%).
[0065] 2) 20 mg of cadmium sulfide powder, 0.8 mg of pyrazine and 4 mg of TCPP (Pt) were placed in a mixed solvent of 12 mL of N,N-dimethylformamide and 3 mL of ethanol, and after ultrasonic treatment for 30 minutes, reaction was carried out at 85°C for 1 day. After centrifugation, the product was obtained;
[0066] 3) The product of step 2) was washed with water and ethanol, and placed in a vacuum drying oven and vacuum dried at 50°C overnight to obtain a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms (yield 85%).
[0067] Comparative Example 2
[0068] Different from Example 1, other methods were used to prepare cadmium sulfide (stirring at room temperature for 2 days)
[0069] A method for preparing a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0070] 1) 832.9 mg of cadmium nitrate tetrahydrate and 648.5 mg of sodium sulfide nonahydrate were added to 50 mL of water, and stirring was carried out at room temperature for 2 days to obtain cadmium sulfide powder. The cadmium sulfide powder was washed with water and ethanol, and then vacuum dried at 50°C overnight;
[0071] 2) 20 mg of cadmium sulfide powder, 0.8 mg of pyrazine and 4 mg of TCPP (Pt) were placed in a mixed solvent of 12 mL of N,N-dimethylformamide and 3 mL of ethanol, and after ultrasonic treatment for 30 minutes, reaction was carried out at 85°C for 1 day. After centrifugation, the product was obtained;
[0072] 3) The product of step 2) was washed with water and ethanol, and placed in a vacuum drying oven and vacuum dried at 50°C overnight to obtain a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms (yield 85%).
[0073] Comparative Example 3
[0074] Different from Example 1, the loading amount of cadmium sulfide used in the preparation of the composite catalyst was different (here, the amount of cadmium sulfide used was 40 mg)
[0075] A method for preparing a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0076] 1) 832.9 mg of cadmium nitrate tetrahydrate and 648.5 mg of sodium sulfide nonahydrate were added to 50 mL of water, and reacted at 180°C for 12 hours to obtain cadmium sulfide powder. The cadmium sulfide powder was washed with water and ethanol, and then dried in a vacuum drying oven at 50°C overnight.
[0077] 2) 40 mg of cadmium sulfide powder, 0.8 mg of pyrazine, and 4 mg of TCPP(Pt) were added to a mixed solvent of 12 mL of N,N-dimethylformamide and 3 mL of ethanol, and ultrasonically treated for 30 minutes, and then reacted at 85°C for 1 day. After centrifugation, the product was obtained.
[0078] 3) The product of step 2) was washed with water and ethanol, and then dried in a vacuum drying oven at 50°C overnight to obtain a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms (yield 95%).
[0079] Comparative Example 4
[0080] Different from Example 1, the raw materials for preparing cadmium sulfide were different, and the temperature was different.
[0081] A method for preparing a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0082] 1) 832.9 mg of cadmium nitrate tetrahydrate and 204.5 mg of thiourea were added to 20 mL of ethylenediamine, and reacted at 120°C for 12 hours to obtain cadmium sulfide powder. The cadmium sulfide powder was washed with water and ethanol, and then dried in a vacuum drying oven at 50°C overnight.
[0083] 2) 20 mg of cadmium sulfide powder, 0.8 mg of pyrazine, and 4 mg of TCPP(Pt) were added to a mixed solvent of 12 mL of N,N-dimethylformamide and 3 mL of ethanol, and ultrasonically treated for 30 minutes, and then reacted at 85°C for 1 day. After centrifugation, the product was obtained.
[0084] 3) The product of step 2) was washed with water and ethanol, and then dried in a vacuum drying oven at 50°C overnight to obtain a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms (yield 95%).
[0085] Comparative Example 5
[0086] Different from Example 1, the different monatomic loading method (here, the physical mixing of monatomic active sites and cadmium sulfide by grinding).
[0087] A method for preparing a composite catalyst of cadmium sulfide surface loaded with platinum monatomic atoms, comprising the following steps:
[0088] 1) 832.9 mg of cadmium nitrate tetrahydrate and 648.5 mg of sodium sulfide nonahydrate were added to 50 mL of water, and reacted at 180 °C for 12 hours to produce cadmium sulfide powder. The cadmium sulfide powder was washed with water and ethanol and then dried at 50 °C under vacuum overnight.
[0089] 2) 40 mg of cadmium sulfide powder and 4 mg of TCPP (Pt) were added to 20 mL of a mixed solvent of ethanol, and after ultrasonic treatment for 30 minutes, suction filtration, drying, and grinding, the product was obtained to produce a composite catalyst of cadmium sulfide surface loaded with platinum single atoms.
[0090] Photocatalytic hydrogen evolution experiment
[0091] The composite catalyst of cadmium sulfide surface loaded with platinum single atoms produced by the above Example 1 and each comparative example was subjected to a photocatalytic hydrogen evolution experiment, and the results are shown in the attached figures and the following analysis:
[0092] As shown in the attached figures and the following analysis: Figure 10 The activity of pure cadmium sulfide was 1.7 mmol / g / h. The activity of the composite catalyst produced in Example 1 could reach 27.97 mmol / g / h (16.4 times higher).
[0093] As shown in the attached figures and the following analysis: Figure 11 The activity of Comparative Example 1 was 9.13 mmol / g / h, the activity of Comparative Example 2 was 1.7 mmol / g / h, the activity of Comparative Example 3 was 15 mmol / g / h, the activity of Comparative Example 4 was 18.1 mol / g / h, and the activity of Comparative Example 5 was 6 mmol / g / h. The results prove that the higher the temperature and the longer the time during the preparation of cadmium sulfide, the higher the activity of the composite catalyst. At the same time, the cadmium sulfide and platinum single atoms connected by a chemical bond have higher activity because of the stronger interaction, which improves the transfer efficiency of photo-generated carriers.
[0094] As shown in the attached figures and the following analysis: Figure 12 After the composite catalyst material was catalyzed, the results remained stable, proving that the composite catalyst material can perform catalytic reactions for a long time.
[0095] As shown in the attached figures and the following analysis: Figure 13 The composite catalyst still had an activity of 11.3 mmol / g / h under sunlight, proving that the composite catalyst material can also maintain high activity in real-world locations.
[0096] As shown in the attached figures and the following analysis: Figure 14 The free energy of hydrogen evolution on the platinum active site was 0.283 eV. The lower free energy reduces the energy barrier of the hydrogen evolution reaction, and at the same time, the free energy also ensures that hydrogen can be evolved in time when it is generated, thereby releasing the active site for the next reaction.
[0097] As shown in the attached figures and the following analysis: Figure 15As shown, the reaction path in the catalytic process is explained. First, cadmium sulfide produces active electrons under the action of light. When the active electrons transfer to the platinum site, the reaction of proton reduction to prepare hydrogen gas occurs. At the same time in the reaction process, lactic acid provides electrons as a sacrificial agent.
[0098] The application is a single-atom composite catalyst grown on the surface of cadmium sulfide by chemical method, which improves the interaction force between the active site and the photoactive substance. The composite catalyst is 16.4 times higher than pure cadmium sulfide. At the same time, the catalyst material also shows high catalytic activity of 11.3 mmol / g / h under sunlight, which shows that the material also has prospects in practical application.
[0099] The above is only to illustrate the technical idea of the application, and cannot limit the protection scope of the application. Any modification made according to the technical idea of the application on the basis of the technical scheme falls within the protection scope of the claims of the application.
Claims
1. A composite catalyst of cadmium sulfide surface supported platinum monatomic atom, characterized in that, The composite catalyst takes cadmium sulfide particles as a substrate, and in-situ grows platinum atom active sites on the surface of the substrate, and loads platinum monatomic atoms on the surface of the cadmium sulfide through a chemical bond; The preparation method of the composite catalyst comprises the following steps: Step 1: placing cadmium nitrate and sodium sulfide in water, reacting at 150-180 DEG C for 6-12 hours, washing with water and ethanol, and then vacuum drying at 50-60 DEG C overnight to obtain cadmium sulfide; Step 2: ultrasonic treating cadmium sulfide, TCPP-Pt and pyrazine in a mixed solution of N,N-dimethylformamide and ethanol for 30 minutes, and then performing a solvothermal reaction at 65-90 DEG C for 12-24 hours to obtain a product after centrifugation; Step 3: drying the product obtained in Step 2 to obtain a composite catalyst with platinum monatomic atoms loaded on the surface of cadmium sulfide.
2. The CdS surface-supported platinum monoatomic complex catalyst according to claim 1, wherein, The platinum monatomic atoms are uniformly distributed on the surface of the cadmium sulfide.
3. The CdS surface-supported platinum monoatomic atom composite catalyst according to claim 1, characterized in that, The cadmium sulfide particles are spherical particles with a size of 20-50 nm.
4. The CdS surface-supported platinum monoatomic atom composite catalyst according to claim 1, characterized in that, The specific surface area of the cadmium sulfide particles is 30 to 60 m 2 / g.
5. The CdS surface-supported platinum monoatomic complex catalyst according to claim 1, wherein, The amount ratio of cadmium sulfide, TCPP-Pt, pyrazine, N,N-dimethylformamide and ethanol is (20-40) mg:4 mg:0.8 mg:12 mL:3 mL.
6. A method for preparing a composite catalyst of cadmium sulfide surface supported platinum monatomic atom, characterized in that, comprises the following steps: Step 1: placing cadmium nitrate and sodium sulfide in water, reacting at 150-180 DEG C for 6-12 hours, washing with water and ethanol, and then vacuum drying at 50-60 DEG C overnight to obtain cadmium sulfide; Step 2: ultrasonic treating cadmium sulfide, TCPP-Pt and pyrazine in a mixed solution of N,N-dimethylformamide and ethanol for 30 minutes, and then performing a solvothermal reaction at 65-90 DEG C for 12-24 hours to obtain a product after centrifugation; wherein the amount ratio of cadmium sulfide, TCPP-Pt, pyrazine, N,N-dimethylformamide and ethanol is (20-40) mg:4 mg:0.8 mg:12 mL:3 mL; Step 3: drying the product obtained in Step 2 to obtain a composite catalyst with platinum monatomic atoms loaded on the surface of cadmium sulfide.
7. The composite catalyst with platinum monatomic atoms loaded on the surface of cadmium sulfide according to any one of claims 1-5, or the application of the composite catalyst with platinum monatomic atoms loaded on the surface of cadmium sulfide prepared by the preparation method of claim 6 in photocatalytic hydrogen evolution.