CN-PtN4 / 6 semiconductor material with photocatalytic hydrogen evolution performance and preparation method thereof
By simultaneously anchoring tetracoordinated and hexacoordinated Pt single atoms on a carbon nitride (CN) carrier, the problem of low activity of semiconductor photocatalysts was solved, efficient photocatalytic water decomposition to produce hydrogen was achieved, and the carrier utilization rate and light absorption were improved.
Patent Information
- Application Number
- CN202510720988.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-09-09
AI Technical Summary
Existing semiconductor photocatalysts have low intrinsic activity, low photogenerated carrier separation efficiency and utilization rate, resulting in poor photocatalytic hydrogen production performance.
By simultaneously anchoring tetracoordinated and hexacoordinated Pt single atoms on a carbon nitride (CN) support, a dual-coordinate configuration is formed, which improves the migration efficiency of photogenerated charges and the utilization rate of carriers.
The performance of photocatalytic hydrogen production is significantly improved, the utilization rate of carriers and the amount of light absorption are increased, the recombination probability of photogenerated electrons and holes is reduced, and efficient photocatalytic water decomposition to produce hydrogen is achieved.
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Figure CN120605753A_ABST
Abstract
Description
(1) Technical field:
[0001] The present invention relates to the field of photocatalytic water hydrogen production, specifically, to a carbon nitride semiconductor material simultaneously loaded with platinum atoms of different coordination numbers and a preparation method thereof, namely, a CN-PtN with photocatalytic hydrogen evolution performance. 4 / 6 Semiconductor materials and methods for preparing the same. (2) Background technology:
[0002] Statistics show that global economic expansion is driving exponential growth in energy demand, with annual consumption of traditional fossil energy projected to double by 2050 compared to current levels. While hydrocarbon fuels continue to support approximately 80% of the world's primary energy supply, their large-scale use has triggered multiple ecological crises that cannot be ignored: greenhouse gas accumulation is causing imbalances in the climate system, fine particulate matter pollution is causing frequent public health incidents, and the human health index is significantly reduced.
[0003] Faced with the dual challenges of energy security and ecological carrying capacity, a new energy transition is imminent. It is worth noting that the solar radiation energy received by the earth's surface every hour (about 4.3×10 20 J) has already exceeded the current global annual energy consumption. This nearly unlimited endowment of clean energy makes it a key alternative to the traditional energy matrix. However, due to the inherent intermittent nature of photovoltaic technology and bottlenecks in grid-scale energy storage, the academic community has gradually focused on semiconductor photocatalytic water splitting to produce hydrogen. By converting solar energy into high-energy-density hydrogen chemical energy in a targeted manner, it is expected to establish an energy transmission system that is both environmentally friendly and economically viable.
[0004] However, since most single semiconductor materials are limited by their inherent catalytic activity and can only exhibit a limited number of exposed active sites, researchers often enhance their inherent activity by introducing highly active co-catalysts, such as metal oxides. [1] , metal particles [2] , clusters, and single atoms [3]. Especially for single atoms, due to their atomic-level dispersion, it can achieve nearly 100% atomic utilization. In addition, extensive studies have shown that low-coordinated single-atom configurations have better catalytic activity, while high-coordinated or even fully coordinated single atoms will greatly reduce their activity due to the serious lack of adsorption sites. However, in the photocatalytic system, fully coordinated terpyridine ruthenium (terpyridine platinum) molecules can be used as photosensitive units to continuously transfer photogenerated electrons to the active sites. However, the only drawback is that this complex molecule is easily degraded to form metal particles under photolysis conditions. Based on this, preventing the degradation and agglomeration of such complex molecules is an important step in promoting the application of photosensitizers in photocatalysis. Anchoring photosensitizers on semiconductor platforms using strong coordination bonds is an effective measure to prevent degradation and inactivation. In 2016, Soo YoungPark et al. used carboxylated terpyridine ruthenium as the basic building unit and constructed MOF using strong coordination bonds to achieve stable anchoring of the photosensitive unit. [4] In addition, constructing single-atom active sites on semiconductor platforms (such as classic carbon nitride-Pt single-atom catalysts) can achieve higher photocatalytic hydrogen evolution activity. [5] However, only the influence of a single site (photosensitive site or active site) on the material is considered. Therefore, constructing low-coordinated single-atom active sites and high-coordinated photosensitive sites on a semiconductor carrier platform may be an effective measure to improve the efficiency of photogenerated charge separation and reduce non-radiative fluorescence recombination.
[0005] The present invention uses carbon nitride (CN) as a single-atom carrier platform, and simultaneously anchors Pt single atoms with four-coordinate and six-coordinate coordination numbers on it through a two-step loading method. The four-coordinate Pt single atom serves as the active site, and the six-coordinate Pt single atom serves as the photosensitive site, which greatly shortens the migration distance of the photogenerated charge, greatly improves the utilization rate of the carrier, and enhances the photocatalytic hydrogen production activity of the catalyst.
[0006] 1S.Y.Wang, ZWAi, XWNiu, WJYang, R.Kang, ZYLin, A.Waseem, L Jiao, H.LJiang, Adv.Mater.2023, 202302512.
[0007] 2Z. Gao, T. Montini, J. Mu, NCLuo, E. Fonda, P. Fornasiero, and F. Wang, J. Am. Chem. Soc. 2024, 146, 24440-24449.
[0008] 3G.M.Ren, JYZhao, ZHZhao, ZZLi, L Wang, ZSZhang, CHLi, XCMeng, Angew.Chem.Int.Ed.2023, 202314408.
[0009] 4D. Kim, ER Whang, SY Park, J. Am. Chem. Soc. 2016, 138, 8698-8701.
[0010] 5G.FSRRocha, MARda Silva, A.Rogolino, GAADiab, LFGNoleto, M.Antonietti, IFTeixeira, Chem.Soc.Rev., 2023, 52, 4878 (3) Summary of the invention:
[0011] The purpose of the present invention is to provide a CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor materials and their preparation methods can solve the key scientific problems of low intrinsic activity of semiconductor photocatalysts and low separation efficiency and utilization rate of photogenerated carriers; the present invention provides a method for simultaneously loading two single atoms with different coordination numbers, which effectively increases the specific surface area and carrier transfer efficiency of the catalyst material, fully improves the utilization rate of carriers, and has excellent photocatalytic water hydrogen production performance and good chemical stability.
[0012] In order to solve the above technical problems, the present invention is implemented through the following technical solutions:
[0013] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 The material has Pt single atoms with different coordination numbers anchored inside the CN, and the whole presents a nanosheet morphology;
[0014] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0015] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0016] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0017] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0018] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0019] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 The preparation method of the semiconductor material includes calcining urea to thermally decompose and generate nanosheet carbon nitride, preparing a platinum single atom anchored CN-PtN4 (tetracoordinated Pt) material, and anchoring the adjacent CN-PtN6 (hexacoordinated Pt) on the CN-PtN4 by secondary loading. The method specifically includes the following steps:
[0020] (1) Preparation of CN material: urea is pyrolyzed at high temperature to obtain CN powder;
[0021] (2) Preparation of CN-PtN4 material: The CN powder obtained in step (1) was mixed with deionized water, and chloroplatinic acid was added. After reaction, the mixture was washed with ethanol and dried to obtain CN-PtN4;
[0022] (3) Preparation of CN-PtN 4 / 6 Materials: CN-PtN4 powder obtained in step (2) and bipyridyl platinum dichloride powder were added to deionized water, mixed and stirred in a water bath, then washed with ethanol and dried to obtain CN-PtN4 with both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder.
[0023] The pyrolysis temperature in step (1) is 500-700°C.
[0024] The pyrolysis heating rate in step (1) is 10-18°C / min.
[0025] The pyrolysis time in step (1) is 2-4 hours.
[0026] In the step (2), the amount of chloroplatinic acid added to every 5-15 mg of CN powder is 0.5-2 mg.
[0027] The mass ratio of CN to chloroplatinic acid in step (2) is 5:2-15:0.5.
[0028] The reaction temperature in step (2) is 60-120°C.
[0029] The reaction time in step (2) is 6-10 hours.
[0030] In the step (3), the amount of bipyridyl dichloroplatinum powder added to every 5-15 mg of CN-PtN4 powder is 2-8 mg.
[0031] In the step (3), the mass ratio of CN-PtN4 powder to bipyridine dichloroplatinum is 5:8-15:2.
[0032] The temperature of the water bath stirring reaction in step (3) is 60-120°C.
[0033] The time of stirring the reaction in the water bath in step (3) is 6-10 hours.
[0034] In the step (1), 5-10 g of urea is placed in a crucible and heated in a tubular furnace. The high-temperature pyrolysis temperature is 500-700° C., and the heating rate of the high-temperature pyrolysis is 10-18° C. min -1 The holding time of high-temperature pyrolysis is 2-4h, and the high-temperature pyrolysis is carried out in an air atmosphere to obtain CN powder;
[0035] In the step (2), 5-15 mg of CN powder obtained in the step (1) is mixed with deionized water, ultrasonicated for 5 minutes, 0.5-2 mg of chloroplatinic acid is added to make the ratio of CN to chloroplatinic acid 5:2-15:0.5, reacted at 60-120° C. for 6-10 hours, then washed with ethanol and dried to obtain CN-PtN4;
[0036] In the step (3), 5-15 mg of CN-PtN4 powder and 2-8 mg of bipyridyl platinum dichloride powder obtained in the step (2) are added to deionized water to make the ratio of CN-PtN4 powder to bipyridyl platinum dichloride be 5:8-15:2, ultrasonically tested for 5 minutes, stirred in a water bath at 60-120° C. for 6-10 hours, then washed with ethanol, and dried to obtain a Pt single atom CN-PtN4 that simultaneously anchors both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder.
[0037] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor materials are used to photocatalytically decompose deionized water to generate hydrogen.
[0038] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor materials are used in the production of new green energy hydrogen.
[0039] Advantages of the present invention:
[0040] The target material CN-PtN of the present invention 4 / 6 Compared with traditional CN-Pt photocatalytic materials, Pt single atoms with different coordination numbers improve carrier utilization and increase light absorption, significantly improving photocatalytic hydrogen production performance.
[0041] The CN-Pt single-atom material containing a dual-coordinate configuration described in the present invention can ensure that the photosensitive unit and the active unit are infinitely close, so that photogenerated electrons and holes can be quickly transferred and efficiently utilized, effectively reducing the recombination probability of photogenerated electrons and holes.
[0042] Compared with traditional photocatalysts, CN-PtN 4 / 6 The material provides a novel concept for the synthesis of double-coordinated single-atom loads, offers a new approach for the preparation of efficient carrier-utilizing photocatalysts, and contributes to the development of carbon nitride photocatalytic semiconductor materials with simple production processes and high hydrogen production efficiency.
[0043] The CN-PtN of the present invention 4 / 6 Semiconductors can be used as a highly efficient photocatalytic material, specifically for photocatalytic deionized water production of hydrogen, which can efficiently convert solar energy into clean energy, effectively alleviating the current shortage of fossil fuels and severe environmental pollution. (4) Description of the accompanying drawings:
[0044] Figure 1 is a scanning electron microscope image of the CN powder in Example 1, with a scale of 1 μm;
[0045] Figure 2 The CN-PtN in Example 1 4 / 6 Transmission electron microscopy images and EDS-Mapping spectra, the scale bar is 500nm;
[0046] Figure 3 This is a spherical aberration corrected electron microscope image of CN-PtN4 in Example 1, with a scale of 500 nm;
[0047] Figure 4 The CN-PtN in Example 1 4 / 6 X-ray diffraction pattern of
[0048] Figure 5 The CN-PtN prepared in Example 1 is under full light irradiation. 4 / 6 Hydrogen production rate curve of the material;
[0049] Figure 6 The CN-PtN prepared in Example 1-7 under full light irradiation 4 / 6 Histogram of hydrogen production rate of materials;
[0050] Figure 7 Schematic diagram of the microscopic atomic structure model of three different CN-Pt materials. (V) Specific implementation methods:
[0051] The present invention will be further described in detail below through specific examples. The following examples may enable those skilled in the art to have a more comprehensive understanding of the present invention, but are not intended to limit the present invention in any way.
[0052] Example 1: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0053] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0054] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0055] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0056] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0057] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0058] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0059] (1) Preparation of CN materials:
[0060] 7 g of urea was placed in a crucible and heated in a tube furnace at a high-temperature pyrolysis temperature of 600 °C, a heating rate of 15 °C min-1, and a holding time of 3 h in an air atmosphere to obtain CN powder.
[0061] (2) Preparation of CN-PtN4:
[0062] 10 mg of CN powder obtained in step (1) was mixed with deionized water, ultrasonicated for 5 min, 0.5 mg of chloroplatinic acid was added, and the mixture was reacted at 70 ° C for 8 h, then washed with ethanol and dried to obtain CN-PtN4;
[0063] (3)CN-PtN 4 / 6 Preparation:
[0064] 10 mg of CN-PtN4 powder obtained in step (2) and 4 mg of bipyridyl dichloroplatinum powder were added to deionized water, ultrasonicated for 5 min, stirred in a water bath at 70 ° C for 8 h, then washed with ethanol and dried to obtain a Pt single atom CN-PtN4 anchoring both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder;
[0065] Figure 1 Scanning electron microscope images of CN prepared in Example 1 with different scales.
[0066] As shown in the scanning electron microscopy images, the prepared CN has a thin nanosheet morphology with a size of 500-800nm.
[0067] Figure 2 The CN-PtN prepared in Example 1 4 / 6 Transmission electron microscopy images and EDS-Mapping spectra.
[0068] As shown in the transmission electron microscopy image, CN-PtN 4 / 6 It shows an extremely thin nanosheet structure, and no Pt clusters and particles are found. The EDS-Mapping spectrum shows the uniform distribution of C, N, and Pt, which proves that CN-PtN 4 / 6 successful synthesis.
[0069] Figure 3 The CN-PtN prepared in Example 1 4 / 6 Spherical aberration correction diagram.
[0070] As shown in the spherical aberration-corrected electron microscope image, atomically dispersed platinum single atom bright spots with a diameter of 0.1-0.3 nm can be found on CN, and no obvious platinum clusters or particles are observed, proving the successful synthesis of platinum single atoms.
[0071] Figure 4 The CN-PtN prepared in Example 1 4 / 6 X-ray diffraction pattern of .
[0072] As shown in the X-ray diffraction pattern, the peak near 27° corresponds to the π-π conjugation of the aromatic ring in CN(002), while the peak at 12.9° represents the size of the CN ring in the basic structure of CN(100). 4 / 6 successful synthesis.
[0073] CN-PtN 4 / 6 Used for photolysis of deionized water to produce hydrogen:
[0074] ① 2.5 mg of previously prepared CN-PtN 4 / 6 Dispersed in 25 mL of triethanolamine deionized water solution (10% volume fraction), which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was 290 after being tested by a radiometer.
[0075] mW / cm 2 ;
[0076] ② Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate.
[0077] Figure 5 For CN-PtN in Example 1 4 / 6 The hydrogen production rate curve of CN as a catalyst under full light. The experimental results show that the hydrogen production rate of CN is only 0.23mmol g -1 h -1 ; The hydrogen production rate of CN-PtN4 is 5.3mmol g -1 h -1 The hydrogen production rate of CN-PtN6 material is 2.4 mmol g -1 h -1 CN-PtN 4 / 6 The hydrogen production rate was the highest, which was 26.5 mmol g -1 h -1 , which is 115 times that of CN. This proves that the CN-PtN prepared in this example 4 / 6 Compared with traditional photocatalysts, heterojunction materials have greatly improved the performance of catalyzing deionized water to produce hydrogen, and are an excellent catalyst material in the photolysis of deionized water to produce hydrogen.
[0078] Example 2: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0079] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0080] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0081] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0082] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0083] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0084] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0085] (1) Preparation of CN material is the same as in Example 1;
[0086] (2) Preparation of CN-PtN4:
[0087] 10 mg of CN powder obtained in step (1) was mixed with deionized water, ultrasonicated for 5 min, 2 mg of chloroplatinic acid was added, and the mixture was reacted at 70 ° C for 8 h, then washed with ethanol and dried to obtain CN-PtN4;
[0088] (3)CN-PtN 4 / 6 The preparation is the same as in Example 1.
[0089] The experimental results show that not only single Pt atoms exist in the ultra-thin CN nanosheet structure, but also a large number of Pt clusters appear.
[0090] 2.5 mg of the CN-PtN prepared in Example 2 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate. Figure 6 The photocatalytic hydrogen evolution performance test showed that the hydrogen production rate in Example 2 was 18.9 mmol g -1 h -1 .
[0091] Example 3: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0092] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0093] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0094] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0095] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0096] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0097] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0098] (1) Preparation of CN material is the same as in Example 1;
[0099] (2) Preparation of CN-PtN4:
[0100] 10 mg of CN powder obtained in step (1) was mixed with deionized water, ultrasonicated for 5 min, 2 mg of chloroplatinic acid was added, and the mixture was reacted at 60 ° C for 8 h, then washed with ethanol and dried to obtain CN-PtN4;
[0101] (3)CN-PtN 4 / 6 The preparation is the same as in Example 1.
[0102] 2.5 mg of the CN-PtN prepared in Example 3 was added 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate. Figure 6 The photocatalytic hydrogen evolution performance test showed that the hydrogen production rate in Example 3 was 13.8 mmol g -1 h -1 .
[0103] Example 4: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0104] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0105] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0106] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0107] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0108] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0109] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0110] (1) Preparation of CN material is the same as in Example 1;
[0111] (2) Preparation of CN-PtN4:
[0112] 10 mg of CN powder obtained in step (1) was mixed with deionized water, ultrasonicated for 5 min, 2 mg of chloroplatinic acid was added, and the mixture was reacted at 100 °C for 8 h, then washed with ethanol and dried to obtain CN-PtN4;
[0113] (3)CN-PtN 4 / 6 The preparation is the same as in Example 1.
[0114] The experimental results show that not only single Pt atoms exist in the ultra-thin CN nanosheet structure, but also a large number of Pt clusters appear.
[0115] 2.5 mg of the CN-PtN prepared in Example 4 was added 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a sacrificial electron donor. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate. Figure 6 The photocatalytic hydrogen evolution performance test shows that the hydrogen production rate in Example 4 is 12.4mmolg -1 h -1 .
[0116] Example 5: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0117] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0118] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0119] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0120] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0121] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0122] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0123] (1) Preparation of CN material is the same as in Example 1;
[0124] (2) Preparation of CN-PtN4:
[0125] 10 mg of CN powder obtained in step (1) was mixed with deionized water, ultrasonicated for 5 min, 0.5 mg of chloroplatinic acid was added, and the mixture was reacted at 70°C for 10 h, followed by washing with ethanol and drying to obtain CN-PtN4;
[0126] (3)CN-PtN 4 / 6 The preparation is the same as in Example 1.
[0127] The experimental results show that not only single Pt atoms exist in the ultra-thin CN nanosheet structure, but also a small number of Pt clusters appear.
[0128] 2.5 mg of the CN-PtN prepared in Example 5 was added 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 min to remove dissolved gases and ensure vacuum conditions.
[0129] The experimental results show that not only single Pt atoms exist in the ultra-thin CN nanosheet structure, but also a large number of Pt clusters appear.
[0130] During the entire photocatalytic process, the reaction system was maintained at 6 °C under the action of circulating condensate. Figure 6 The photocatalytic hydrogen evolution performance test showed that the hydrogen production rate in Example 5 was 22.2 mmol g -1 h -1 .
[0131] Example 6: CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, namely CN-PtN 4 / 6 Materials, wherein Pt single atoms with different coordination numbers are anchored inside the CN;
[0132] Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm;
[0133] The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm;
[0134] The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
[0135] A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
[0136] Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
[0137] A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material comprises the following steps:
[0138] (1) Preparation of CN material is the same as in Example 1;
[0139] (2) The preparation of CN-PtN4 was the same as in Example 1;
[0140] (3)CN-PtN 4 / 6 Preparation:
[0141] 10 mg of CN-PtN4 powder obtained in step (2) and 2 mg of bipyridyl dichloroplatinum powder were added to deionized water, ultrasonicated for 5 min, stirred in a water bath at 70 ° C for 8 h, then washed with ethanol and dried to obtain a Pt single atom CN-PtN4 anchoring both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder;
[0142] The experimental results show that the ultrathin CN nanosheets have a uniform structure and no Pt particles or clusters were found.
[0143] 2.5 mg of the CN-PtN prepared in Example 6 was added 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate. Figure 6The photocatalytic hydrogen evolution performance test showed that the hydrogen production rate in Example 6 was 21.3 mmol g -1 h -1 .
[0144] Example 7:
[0145] (1) Preparation of CN material is the same as in Example 1;
[0146] (2) The preparation of CN-PtN4 was the same as in Example 1;
[0147] (3)CN-PtN 4 / 6 Preparation:
[0148] 10 mg of CN-PtN4 powder obtained in step (2) and 8 mg of bipyridyl dichloroplatinum powder were added to deionized water, ultrasonicated for 5 min, stirred in a water bath at 70 ° C for 8 h, then washed with ethanol and dried to obtain a Pt single atom CN-PtN4 anchoring both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder;
[0149] The experimental results show that the ultrathin CN nanosheets have a uniform structure and no Pt particles or clusters were found.
[0150] 2.5 mg of the CN-PtN prepared in Example 7 was added 4 / 6 Dispersed in 25 mL of deionized triethanolamine (10% by volume) solution, which contained 2.5 mL of triethanolamine as a hole sacrificial agent. A 300W xenon lamp was used to simulate sunlight, and the light intensity at the working electrode of the photoelectrochemical cell was measured by a radiometer to be 290 mW / cm 2 Before the photocatalytic reaction, the reaction vessel was evacuated for 30 minutes to remove dissolved gases and ensure vacuum conditions. During the entire photocatalytic process, the reaction system was maintained at 6°C under the action of circulating condensate. Figure 6 The photocatalytic hydrogen evolution performance test showed that the hydrogen production rate in Example 7 was 19.2 mmol / g -1 h -1 .
[0151] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the present invention and the claims. These all fall within the scope of protection of the present invention.
Claims
1. A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Semiconductor material, characterized in that Pt single atoms with different coordination numbers are anchored inside the CN.
2. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 1 4 / 6 Semiconductor material, characterized in that A single Pt atom is introduced into the CN to form a double-coordinated single-atom structure.
3. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 1 4 / 6 Semiconductor material, characterized in that Pt single atoms with four-coordinated and six-coordinated coordination numbers are simultaneously anchored on the CN surface to form Pt-N chemical bonds.
4. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 1 4 / 6 Semiconductor material, characterized in that Pt single atoms are anchored on the CN nanosheet layer, and the diameter of the CN is about 500-800 nm and the thickness is 3-5 nm; The diameter of a single Pt atom in the CN-Pt material is 0.1-0.3 nm; The CN-Pt has a diameter of 500-700 nm and a thickness of 3-5 nm.
5. A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 A method for preparing a semiconductor material, characterized in that The following steps are involved: (1) Preparation of CN material: urea is pyrolyzed at high temperature to obtain CN powder; (2) Preparation of CN-PtN4 material: The CN powder obtained in step (1) was mixed with deionized water, and chloroplatinic acid was added. After reaction, the mixture was washed with ethanol and dried to obtain CN-PtN4; (3) Preparation of CN-PtN 4 / 6 Materials: CN-PtN4 powder obtained in step (2) and bipyridyl platinum dichloride powder were added to deionized water, mixed and stirred in a water bath, then washed with ethanol and dried to obtain CN-PtN4 with both tetracoordinate and hexacoordinate coordination numbers. 4 / 6 powder.
6. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 5 4 / 6 A method for preparing a semiconductor material, characterized in that The pyrolysis temperature in step (1) is 500-700°C; The pyrolysis heating rate in step (1) is 10-18°C / min; The pyrolysis time in step (1) is 2-4 hours.
7. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 5 4 / 6 A method for preparing a semiconductor material, characterized in that In step (2), the mass ratio of CN to chloroplatinic acid is 5:2-15:0.5; The reaction temperature in step (2) is 60-120°C; The reaction time in step (2) is 6-10 hours.
8. A CN-PtN with photocatalytic hydrogen evolution performance according to claim 5 4 / 6 A method for preparing a semiconductor material, characterized in that In step (3), the mass ratio of CN-PtN4 powder to bipyridine dichloroplatinum is 5:8-15:2; The temperature of the water bath stirring reaction in step (3) is 60-120°C; The time of stirring the reaction in the water bath in step (3) is 6-10 hours.
9. A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Application of semiconductor materials, characterized by It is used for photocatalytic decomposition of deionized water to generate hydrogen.
10. A CN-PtN with photocatalytic hydrogen evolution performance 4 / 6 Application of semiconductor materials, characterized by It is used for the production of new green energy hydrogen.