Nanoparticle-assembled composite photocatalytic metamaterial as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of catalytic materials, and provides a composite photocatalytic metamaterial assembled by nanoparticles as well as a preparation method and application of the composite photocatalytic metamaterial. The composite photocatalytic metamaterial assembled by the nanoparticles comprises a metal film layer, a semiconductor film layer and a metal particle layer (formed by dispersedly distributed metal nanoparticles or metal nanoclusters) which are sequentially stacked. Strong coupling of a plasmon mode of the metal nanoparticles or the metal nanoclusters and an optical cavity mode of the metal film layer / semiconductor film causes great local field enhancement, meanwhile, excitation efficiency of plasmon hot electrons is improved, and due to the fact that the hot electrons can directly participate in photocatalysis, the efficient excitation of the plasmon hot electrons can improve the photocatalytic performance of the device. The photocatalytic efficiency is improved. In addition, due to the fact that the multi-mode coupled and nanoparticle assembled composite photocatalytic metamaterial further has the characteristic of broadband response, the light absorption efficiency and the sunlight utilization efficiency are improved, and finally the photocatalytic efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of catalytic materials, and in particular to a composite photocatalytic metamaterial assembled by nanoparticles, and a preparation method and application thereof. Background Art

[0002] Plasmons (Surface Plasmon Resonance, SPR) of metal nanostructures are electromagnetic waves localized on the surface of metal nanostructures, which can significantly enhance the interaction between light and matter. The application of plasmons in photocatalysis has become an important research field. For example, in the photocatalytic decomposition of water to produce hydrogen, plasmons can significantly increase the light absorption efficiency of materials and promote the separation of photogenerated electron-hole pairs in semiconductors, thereby improving the photocatalytic efficiency. Compared with traditional pure semiconductor photocatalysis, plasmon-enhanced photocatalytic materials have made great progress in improving light absorption efficiency and catalytic efficiency. However, the plasmon nanomaterials commonly used at present are generally single nanoparticles, with low efficiency in utilizing solar energy, and the light absorption efficiency and absorption wavelength range are limited by the plasmon resonance of the nanoparticles themselves. Therefore, it is difficult to meet the requirements for photocatalytic efficiency when plasmon nanomaterials are directly used as photocatalytic materials. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a composite photocatalytic metamaterial assembled by nanoparticles and a preparation method and application thereof. The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention has high photocatalytic efficiency when directly used as a photocatalytic material.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A composite photocatalytic metamaterial assembled by nanoparticles, comprising a metal film layer, a semiconductor film layer and a metal particle layer stacked in sequence;

[0006] The metal particle layer is formed of dispersed metal nanoparticles or metal nanoclusters.

[0007] Preferably, the metal film layer is a single layer or a multi-layer composite;

[0008] The material of each layer in the single-layer or multi-layer composite is independently one or more of gold, silver, platinum, copper and aluminum.

[0009] Preferably, the thickness of the metal film layer is 10 to 500 nanometers.

[0010] Preferably, the semiconductor film layer is a single layer or a multi-layer composite;

[0011] The material of each layer in the single-layer or multi-layer composite is independently graphene, TiO2, ZnO, Al2O3, CdS, WO3, MoO3, SrTiO3, BiFeO3, g-C3N4 or MoS2.

[0012] Preferably, the semiconductor film layer has a thickness of 1 to 500 nanometers.

[0013] Preferably, the metal nanoparticles or metal nanoclusters are made of one or more of gold, silver, platinum, palladium, rhodium, copper and aluminum.

[0014] Preferably, the particle size of the metal nanoparticles or metal nanoclusters is 1 to 100 nanometers.

[0015] The present invention also provides a method for preparing the composite photocatalytic metamaterial assembled by nanoparticles described in the above technical solution, comprising the following steps:

[0016] A metal film layer, a semiconductor film layer and a metal particle layer are sequentially prepared on the surface of a substrate to obtain a composite photocatalytic metamaterial assembled by the nanoparticles.

[0017] Preferably, the preparation method of the metal film layer includes electron beam evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, atomic layer deposition or electroplating;

[0018] The semiconductor film preparation method includes thermal evaporation, electron beam evaporation, physical vapor deposition, chemical vapor deposition, atomic layer deposition, sol-gel method or solvent thermal reaction method;

[0019] The metal particle layer is prepared by cluster beam deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition solvent reaction method or gas aggregation method.

[0020] The present invention also provides the use of the composite photocatalytic metamaterial assembled by nanoparticles described in the above technical solution or the composite photocatalytic metamaterial assembled by nanoparticles prepared by the preparation method described in the above technical solution in photocatalysis, surface enhanced Raman, solar cells, plasmon enhanced photodetectors or plasmon enhanced fluorescence.

[0021] The invention provides a composite photocatalytic metamaterial assembled by nanoparticles.

[0022] Beneficial Effects

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The composite photocatalytic metamaterial assembled by nanoparticles of the present invention is composed of a metal film layer, a semiconductor film layer and a metal particle layer (the metal particle layer is formed by dispersed metal nanoparticles or metal nanoclusters). The strong coupling of the plasmon mode of the metal nanoparticles or metal nanoclusters with the optical cavity mode of the metal film layer / semiconductor film leads to a great local field enhancement, and at the same time improves the excitation efficiency of plasmon hot electrons. Since the hot electrons generated by plasmon decay can directly participate in photocatalysis, the efficient excitation of plasmon hot electrons greatly improves the photocatalytic efficiency. In addition, due to multi-mode coupling, the composite photocatalytic metamaterial assembled by nanoparticles also has the characteristics of broadband response, which overcomes the problem of limited absorption wavelength range of single nanoparticles as plasmon materials, thereby improving the light absorption efficiency and sunlight utilization efficiency, and ultimately improving the photocatalytic efficiency.

[0025] 2. The photocatalytic mechanism of the composite photocatalytic metamaterial assembled by nanoparticles of the present invention is significantly improved compared with the traditional semiconductor photocatalytic mechanism. This is mainly reflected in that the plasmon hot electrons in the composite photocatalytic metamaterial assembled by nanoparticles of the present invention can directly participate in the photocatalytic reaction, and the hot electrons come from the metal nanoparticles or metal nanoclusters in the surface metal particle layer, which are not limited by the bandgap width of the semiconductor, so that the sunlight can be efficiently utilized (i.e., the light absorption efficiency and sunlight utilization efficiency are improved) for photocatalytic reaction, thereby achieving an improvement in photocatalytic efficiency.

[0026] 3. The composite photocatalytic metamaterial assembled by the nanoparticles of the present invention can be used not only for photocatalysis, but also for surface enhanced Raman spectroscopy (SERS), solar cells, plasmon enhanced photodetectors, plasmon enhanced fluorescence and other fields, and has strong universality.

[0027] 4. The composite photocatalytic metamaterial assembled from nanoparticles of the present invention has high stability and is easier to recycle than powder materials.

[0028] The present invention also provides a method for preparing the composite photocatalytic metamaterial assembled by nanoparticles described in the above technical solution. The preparation method of the present invention has a simple process, and the prepared composite photocatalytic metamaterial assembled by nanoparticles has good uniformity, low cost, easy preparation, and is suitable for large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a composite photocatalytic metamaterial assembled from nanoparticles provided by the present invention;

[0030] Figure 2 The cross-sectional SEM morphology of the composite photocatalytic metamaterial assembled from nanoparticles obtained in Example 2;

[0031] Figure 3The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from the nanoparticles obtained in Example 1 under 60 minutes of simulated sunlight irradiation;

[0032] Figure 4 The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from the nanoparticles obtained in Example 2 under 60 minutes of simulated sunlight irradiation;

[0033] Figure 5 The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from the nanoparticles obtained in Example 3 under 60 minutes of simulated sunlight irradiation;

[0034] Figure 6 The photocatalytic hydrogen production of the photocatalytic material obtained in Comparative Example 1 under 60 minutes of simulated sunlight irradiation;

[0035] Figure 7 This is a cycle test stability diagram of the composite photocatalytic metamaterial assembled with nanoparticles obtained in Example 2;

[0036] Reference numerals: 1 is a substrate, 2 is a metal film layer, 3 is a semiconductor film layer, and 4 is a metal particle layer. DETAILED DESCRIPTION

[0037] Figure 1 Schematic diagram of the structure of the composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention, 1 is a substrate, 2 is a metal film layer, 3 is a semiconductor film layer, and 4 is a metal particle layer; Figure 1 The technical solution of the present invention is described in detail.

[0038] The present invention provides a composite photocatalytic metamaterial assembled by nanoparticles, comprising a metal film layer, a semiconductor film layer and a metal particle layer stacked in sequence;

[0039] The metal particle layer is formed of dispersed metal nanoparticles or metal nanoclusters.

[0040] Unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0041] The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention includes a metal film layer, and the metal film layer is preferably a single layer or a multi-layer composite; the material of each layer in the single layer or the multi-layer composite is independently preferably one or more of gold, silver, platinum, copper and aluminum. In the present invention, when the material of each layer in the single layer or the multi-layer composite is independently preferably one or more of gold, silver, platinum, copper and aluminum, each layer in the single layer or the multi-layer composite is an alloy, that is, the material of the metal film layer is an alloy; when the material of each layer in the multi-layer composite is one of gold, silver, platinum, copper and aluminum, but the material of each layer in the multi-layer composite is not completely the same, the material of the metal film layer composed of the multi-layer composite can also be called an alloy; when the material of the single layer is one of gold, silver, platinum, copper and aluminum, the material of the metal film layer can also be called a metal element. In the present invention, the thickness of the metal film layer is preferably 10 to 500 nanometers, specifically 10 nanometers, 50 nanometers, 100 nanometers, 150 nanometers, 200 nanometers, 250 nanometers, 300 nanometers, 350 nanometers, 400 nanometers, 450 nanometers or 500 nanometers.

[0042] The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention is preferably stacked on a substrate, the metal film layer is in contact with the substrate, and the material of the substrate is preferably an insulator, a semiconductor, a silicon-on-insulator material (SOI), a composite material of SOI, silicon and metal, or a polymer. In the present invention, the insulator is preferably quartz glass or ceramic, and the ceramic is preferably alumina. In the present invention, the semiconductor is preferably silicon, GaN or GaAs. In the present invention, the polymer is preferably silica gel, polyvinyl alcohol resin (PVA), polyethylene terephthalate plastic (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS) or polytetrafluoroethylene (PTFE).

[0043] The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention includes a semiconductor film layer stacked on another surface of the metal film layer, and the semiconductor film layer is preferably a single layer or a multi-layer composite; the material of each layer in the single layer or the multi-layer composite is independently preferably graphene, TiO2, ZnO, Al2O3, CdS, WO3, MoO3, SrTiO3, BiFeO3, g-C3N4 or MoS2. In the present invention, the thickness of the semiconductor film layer is preferably 1 to 500 nanometers, specifically 1 nanometer, 5 nanometers, 10 nanometers, 30 nanometers, 50 nanometers, 100 nanometers, 150 nanometers, 200 nanometers, 250 nanometers, 300 nanometers, 350 nanometers, 400 nanometers, 450 nanometers or 500 nanometers. In the present invention, the metal film layer and the semiconductor film jointly provide an optical cavity mode.

[0044] The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention includes a metal particle layer stacked on a semiconductor film layer, and the metal particle layer is formed by dispersed metal nanoparticles or metal nanoclusters. In the present invention, the material of the metal nanoparticles or metal nanoclusters is preferably one or more of gold, silver, platinum, palladium, rhodium, copper and aluminum. In the present invention, when the material of each metal nanoparticle or metal nanocluster in the metal nanoparticles or metal nanoclusters is preferably a plurality of gold, silver, platinum, palladium, rhodium, copper and aluminum, the material of the metal nanoparticles or metal nanoclusters is preferably referred to as an alloy, that is, the material of the metal particle layer is preferably an alloy. In the present invention, when the material of each metal nanoparticle or metal nanocluster in the metal nanoparticles or metal nanoclusters is preferably one of gold, silver, platinum, palladium, rhodium, copper and aluminum, but the materials of different metal nanoparticles or metal nanoclusters are different, the material of the metal nanoparticles or metal nanoclusters can be referred to as a metal mixture, that is, the material of the metal particle layer is preferably a metal mixture. In the present invention, when the material of each metal nanoparticle or metal nanocluster in the metal nanoparticle or metal nanocluster is preferably one of gold, silver, platinum, palladium, rhodium, copper and aluminum, and the materials of different metal nanoparticles or metal nanocluster are the same, the material of the metal nanoparticle or metal nanocluster can be called a metal single substance, that is, the material of the metal particle layer is preferably a metal single substance. In the present invention, the particle size of the metal nanoparticle or metal nanocluster is preferably 1 to 100 nanometers, specifically 1 nanometer, 5 nanometers, 10 nanometers, 12 nanometers, 15 nanometers, 20 nanometers, 25 nanometers, 30 nanometers, 35 nanometers, 40 nanometers, 45 nanometers, 50 nanometers, 55 nanometers, 60 nanometers, 65 nanometers, 70 nanometers, 75 nanometers, 80 nanometers, 85 nanometers, 90 nanometers, 95 nanometers or 100 nanometers. In the present invention, the metal particle layer can provide a plasmon mode.

[0045] The present invention also provides a method for preparing the composite photocatalytic metamaterial assembled by nanoparticles described in the above technical solution, comprising the following steps:

[0046] A metal film layer, a semiconductor film layer and a metal particle layer are sequentially prepared on the surface of a substrate to obtain a composite photocatalytic metamaterial assembled by the nanoparticles.

[0047] In the present invention, the substrate is preferably cleaned before use. The cleaning method and operation are not specifically limited, as long as the impurities and oxide film on the substrate can be completely removed.

[0048] In the present invention, the method for preparing the metal film layer preferably includes electron beam evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, atomic layer deposition or electroplating, specifically electron beam evaporation or magnetron sputtering. The present invention does not specifically limit the parameters of the electron beam evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, atomic layer deposition or electroplating, as long as the metal film layer of the required material and thickness can be obtained.

[0049] In the present invention, the method for preparing the semiconductor film layer preferably includes thermal evaporation, electron beam evaporation, physical vapor deposition, chemical vapor deposition, atomic layer deposition, sol-gel method or solvent thermal reaction method, specifically thermal evaporation or electron beam evaporation. The present invention does not specifically limit the parameters of the thermal evaporation, electron beam evaporation, physical vapor deposition, chemical vapor deposition, atomic layer deposition, sol-gel method or solvent thermal reaction method, as long as a semiconductor film layer of the required material and thickness can be obtained.

[0050] In the present invention, the method for preparing the metal particle layer is preferably cluster beam deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition solvent reaction method or gas aggregation method, specifically cluster beam deposition or gas aggregation method. The present invention does not specifically limit the parameters of the cluster beam deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition solvent reaction method or gas aggregation method, as long as a metal particle layer of the required material and particle size can be obtained. In the present invention, when the cluster beam deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition solvent reaction method or gas aggregation method obtains a continuous film layer, the present invention preferably also includes heat treatment of the obtained continuous film layer to obtain a metal particle layer. The present invention does not specifically limit the parameters and process of the heat treatment, and the operations familiar to those skilled in the art can be used. In the present invention, the cluster beam deposition or gas aggregation method can directly obtain a dispersed metal particle layer.

[0051] The present invention also provides the use of the composite photocatalytic metamaterial assembled by nanoparticles described in the above technical solution or the composite photocatalytic metamaterial assembled by nanoparticles prepared by the preparation method described in the above technical solution in photocatalysis, surface enhanced Raman, solar cells, plasmon enhanced photodetectors or plasmon enhanced fluorescence.

[0052] In the present invention, the photocatalysis preferably includes photocatalytic decomposition of water or photocatalytic degradation of pollutants.

[0053] The present invention does not specifically limit the application mode of the composite photocatalytic metamaterial assembled by the nanoparticles, and those skilled in the art can configure it according to actual needs.

[0054] The composite photocatalytic metamaterial assembled by nanoparticles provided by the present invention, its preparation method and application are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0055] Example 1

[0056] A method for preparing a composite photocatalytic metamaterial assembled by nanoparticles comprises the following steps:

[0057] (1) Quartz glass was selected as the substrate, and an Ag metal film layer was deposited on the surface of the substrate by electron beam evaporation. The thickness of the Ag metal film layer was 10 nanometers.

[0058] (2) A CdS semiconductor film is deposited on the surface of the Ag metal film layer by a thermal evaporation method. The thickness of the CdS semiconductor film is 10 nanometers.

[0059] (3) Pd small-sized nanoparticles or nanoclusters are deposited on the surface of the semiconductor film layer using a cluster beam deposition method, and the average size of the Pd small-sized nanoparticles or nanoclusters is 12 nanometers.

[0060] Example 2

[0061] A method for preparing a composite photocatalytic metamaterial assembled by nanoparticles comprises the following steps:

[0062] (1) Silicon was selected as the substrate, and an Au metal film layer was deposited on the surface of the substrate by magnetron sputtering. The thickness of the Au metal film layer was 350 nanometers.

[0063] (2) A TiO2 semiconductor film is deposited on the surface of the Au metal film layer by electron beam evaporation. The thickness of the TiO2 semiconductor film is 30 nanometers.

[0064] (3) Au small-sized nanoparticles or nanoclusters are deposited on the surface of the semiconductor film layer by a magnetron sputtering method, and the average size of the Au small-sized nanoparticles or nanoclusters is 10 nanometers.

[0065] Example 3

[0066] A method for preparing a composite photocatalytic metamaterial assembled by nanoparticles comprises the following steps:

[0067] (1) Quartz glass was selected as the substrate, and a Cu metal film layer was deposited on the surface of the substrate by magnetron sputtering. The thickness of the Cu metal film layer was 500 nanometers.

[0068] (2) A ZnO semiconductor film is deposited on the surface of the Cu metal film layer by a thermal evaporation method. The thickness of the ZnO semiconductor film is 500 nanometers.

[0069] (3) Ag / Cu alloy small-sized nanoparticles or nanoclusters are deposited on the surface of the semiconductor film layer by a gas aggregation method, and the average size of the Ag / Cu alloy small-sized nanoparticles is 100 nanometers.

[0070] Comparative Example 1

[0071] Quartz glass is selected as a substrate, and Pd small-sized nanoparticles or nanoclusters are deposited on the surface of the substrate by cluster beam deposition. The average size of the Pd small-sized nanoparticles or nanoclusters is 12 nanometers.

[0072] Figure 2 This is the cross-sectional SEM morphology of the composite photocatalytic metamaterial assembled with nanoparticles obtained in Example 2. Figure 2 It can be seen that the composite photocatalytic supermaterial assembled by the obtained nanoparticles is composed of a distinct three-layer structure, namely, a metal film layer, a semiconductor film layer and a metal particle layer from bottom to top. The metal film layer and the semiconductor film layer are both dense film layers, while the metal particle layer is composed of nanoparticles and is porous.

[0073] The composite photocatalytic metamaterials assembled from the nanoparticles obtained in Examples 1 to 3 and the photocatalytic material obtained in Comparative Example 1 were placed in 100 mL of water, respectively, and irradiated with simulated sunlight of 300 W intensity. The hydrogen production after irradiation for 60 minutes was measured. The results are as follows: Figure 3 to Figure 6 As shown, Figure 3 The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from the nanoparticles obtained in Example 1 under 60 minutes of simulated sunlight irradiation; Figure 4 The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from the nanoparticles obtained in Example 2 under 60 minutes of simulated sunlight irradiation; Figure 5 The photocatalytic hydrogen production of the composite photocatalytic metamaterial assembled from nanoparticles obtained in Example 3 under simulated sunlight irradiation for 60 minutes, Figure 6 This is the photocatalytic hydrogen production of the photocatalytic material obtained in Comparative Example 1 under 60 minutes of simulated sunlight irradiation.

[0074] from Figure 3 It can be seen that an obvious hydrogen peak appears in the gas chromatogram, and the integrated area of ​​the peak is 12113, indicating that the composite photocatalytic metamaterial assembled by nanoparticles prepared in Example 1 can effectively catalyze water decomposition to produce hydrogen.

[0075] from Figure 4 It can be seen that an obvious hydrogen peak also appears in the gas chromatogram, and the integrated area of ​​the peak is 34452, which also shows that the composite photocatalytic metamaterial assembled by the nanoparticles obtained in Example 2 can effectively catalyze water decomposition to produce hydrogen. Compared with Example 1, the composite photocatalytic metamaterial assembled by the nanoparticles obtained in Example 2 has a slightly higher hydrogen production.

[0076] from Figure 5 It can be seen that an obvious hydrogen peak also appears in the gas chromatogram, and the integrated area of ​​the peak is 13380, which also shows that the composite photocatalytic metamaterial assembled by the nanoparticles obtained in Example 3 can effectively catalyze water decomposition to produce hydrogen. Compared with Example 1 and Example 2, the hydrogen production of the composite photocatalytic metamaterial assembled by the nanoparticles obtained in Example 3 is equivalent to that of Example 1.

[0077] The hydrogen production amounts of the composite photocatalytic metamaterials assembled by nanoparticles obtained in Examples 1 to 3 are different. The main reason is that the thickness of the intermediate semiconductor film layer is different, which makes the light absorption of the composite photocatalytic metamaterials assembled by nanoparticles different, thereby affecting the photocatalytic efficiency. However, in general, the composite photocatalytic metamaterials assembled by nanoparticles with different structural parameters all show high photocatalytic activity.

[0078] from Figure 6 It can be seen that no obvious hydrogen peak appears in the gas chromatogram, indicating that the photocatalytic material prepared in Comparative Example 1 has no photocatalytic activity.

[0079] The composite photocatalytic metamaterial assembled with nanoparticles obtained in Example 2 was placed in 100 mL of water, irradiated with simulated sunlight with an intensity of 300 W, and the hydrogen production after 60 minutes of irradiation was measured, which was recorded as the 1st cycle; then the composite photocatalytic metamaterial assembled with the nanoparticles was taken out and placed in 100 mL of water again, irradiated with simulated sunlight with an intensity of 300 W, and the hydrogen production after 60 minutes of irradiation was measured, which was recorded as the 2nd cycle; then the composite photocatalytic metamaterial assembled with the nanoparticles was taken out and placed in 100 mL of water again, irradiated with simulated sunlight with an intensity of 300 W, and the hydrogen production after 60 minutes of irradiation was measured, which was recorded as the 3rd cycle. The final hydrogen production amounts of the 1st cycle, the 2nd cycle, and the 3rd cycle are as follows: Figure 7 shown. Figure 7 The stability diagram of the cyclic test of the composite photocatalytic metamaterial assembled by nanoparticles obtained in Example 2; Figure 7 It can be seen that after 3 hours of cyclic testing, the hydrogen production of the composite photocatalytic metamaterial assembled by the obtained nanoparticles did not show obvious attenuation, indicating that the composite photocatalytic metamaterial assembled by the obtained nanoparticles has continuous photocatalytic hydrogen production capability and high stability.

[0080] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite photocatalytic metamaterial assembled from nanoparticles, characterized in that: It includes a metal film layer, a semiconductor film layer and a metal particle layer stacked in sequence; The metal particle layer is formed of dispersed metal nanoparticles or metal nanoclusters.

2. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1, characterized in that: The metal film layer is a single layer or a multi-layer composite; The material of each layer in the single-layer or multi-layer composite is independently one or more of gold, silver, platinum, copper and aluminum.

3. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1 or 2, characterized in that: The thickness of the metal film layer is 10 to 500 nanometers.

4. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1, characterized in that: The semiconductor film layer is a single layer or a multi-layer composite; The material of each layer in the single-layer or multi-layer composite is independently graphene, TiO2, ZnO, Al2O3, CdS, WO3, MoO3, SrTiO3, BiFeO3, g-C3N4 or MoS2.

5. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1 or 4, characterized in that: The thickness of the semiconductor film layer is 1 to 500 nanometers.

6. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1, characterized in that: The material of the metal nanoparticles or metal nanoclusters is one or more of gold, silver, platinum, palladium, rhodium, copper and aluminum.

7. The composite photocatalytic metamaterial assembled by nanoparticles according to claim 1 or 6, characterized in that: The particle size of the metal nanoparticles or metal nanoclusters is 1 to 100 nanometers.

8. The method for preparing the composite photocatalytic metamaterial assembled by nanoparticles according to any one of claims 1 to 7, characterized in that: The following steps are involved: A metal film layer, a semiconductor film layer and a metal particle layer are sequentially prepared on the surface of a substrate to obtain a composite photocatalytic metamaterial assembled by the nanoparticles.

9. The preparation method according to claim 8, characterized in that: The preparation method of the metal film layer includes electron beam evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, atomic layer deposition or electroplating; The semiconductor film preparation method includes thermal evaporation, electron beam evaporation, physical vapor deposition, chemical vapor deposition, atomic layer deposition, sol-gel method or solvent thermal reaction method; The metal particle layer is prepared by cluster beam deposition, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition solvent reaction method or gas aggregation method.

10. Use of the composite photocatalytic metamaterial assembled by nanoparticles according to any one of claims 1 to 7 or the composite photocatalytic metamaterial assembled by the preparation method according to any one of claims 8 to 9 in photocatalysis, surface enhanced Raman, solar cells, plasmon enhanced photodetectors or plasmon enhanced fluorescence.

Images