Recyclable photo / thermal catalyst as well as preparation method and application thereof

Abstract

The invention discloses a recyclable photo / thermal catalyst and a preparation method and application thereof. The catalyst comprises a porous carrier and a multi-layer composite catalyst loaded on the porous carrier, the multi-layer composite catalyst comprises a core layer catalyst, a regeneration layer catalyst, a first reaction active layer catalyst, a second reaction active layer catalyst and a photo-thermal conversion layer catalyst, the layers of the multi-layer composite catalyst are longitudinally arranged, and the catalysts of the adjacent layers are different; the core layer catalyst is in direct contact with the porous support. Depositing the core layer catalyst on the porous carrier by adopting a physical deposition method, and sequentially depositing the rest layers of catalysts according to a longitudinal arrangement mode; and calcining in a reducing atmosphere every time a layer of catalyst is deposited. Through multi-component catalyst arrangement, the problems that a traditional photocatalytic material is unstable and prone to inactivation are solved, long service life, high yield and high selectivity are considered, cyclic regeneration of the catalyst is achieved, and the continuous photocatalytic service life exceeds the international level by 30% or above.

Description

Technical Field

[0001] The present invention relates to a catalyst for producing hydrocarbon fuels, a preparation method thereof and an application, and particularly relates to a recyclable photocatalyst / thermocatalyst and a preparation method and an application thereof. Background Art

[0002] In the past few years, the average carbon dioxide concentration in the global atmosphere has increased sharply, causing problems such as global warming and environmental pollution. Using carbon dioxide as a carbon source to produce value-added compounds through catalytic reactions is an extremely promising strategy.

[0003] At present, the process of converting carbon dioxide into hydrocarbon fuels by photocatalysis / thermocatalysis provides an effective way for solar energy to be converted into chemical energy. Therefore, catalysts with broad and strong light absorption, effective charge separation, long-term operational stability, and appropriate redox ability for the target reaction are the key to achieving efficient photocatalytic reduction of carbon dioxide to hydrocarbon fuels. However, due to the loss of active states and morphological changes in the photocatalyst / thermocatalyst during the light irradiation process, the commercialization of photocatalytic reduction of carbon dioxide is still hindered by the instability of the catalyst.

[0004] In recent years, the use of hole scavengers and the construction of heterostructures to maintain the required active states have made the commercialization of photocatalytic reduction of carbon dioxide possible. However, the use of non-renewable hole scavengers and the need for ineffective and energy-consuming photocatalyst regeneration processes will inevitably introduce additional energy and costs. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a recyclable photocatalyst / thermocatalyst with enhanced solar energy absorption and extended recyclability;

[0006] The second object of the present invention is to provide a preparation method for the above-mentioned recyclable photocatalyst / thermocatalyst;

[0007] The third object of the present invention is to provide an application of the above-mentioned recyclable photocatalyst / thermocatalyst.

[0008] Technical Solution: The recyclable photocatalyst / thermocatalyst described in the present invention includes a porous support and a multi-layer composite catalyst supported on the porous support. The multi-layer composite catalyst includes a core layer catalyst, a regeneration layer catalyst, a first reaction active layer catalyst, a second reaction active layer catalyst, and a photo-thermal conversion layer catalyst; the layers of the multi-layer composite catalyst are arranged longitudinally, and the catalysts of adjacent layers are different; the core layer catalyst is in direct contact with the porous support.

[0009] Among them, the core layer catalyst, the regeneration layer catalyst, the first reaction active layer catalyst, and the second reaction active layer catalyst are each composed of one, multiple, or doped nanomaterials; the types of the first reaction active layer catalyst and the second reaction active layer catalyst in the multi-layer composite catalyst are different.

[0010] Among them, the core layer catalyst includes a composite material of one or two or more of perovskite-type nanomaterials, metal oxide nanomaterials, and non-metal carbon and nitride nanomaterials.

[0011] Among them, the regeneration layer catalyst is a metal fluoride composite nanomaterial doped with at least one element.

[0012] Among them, the first reaction active layer catalyst and the second reaction active layer catalyst are at least one of MOFs, COFs nanomaterials, or nanometal materials; the nanometal materials include a composite material of one or two or more of noble metal nanomaterials, non-noble metal nanomaterials, transition metal nanomaterials, and rare earth metal nanomaterials.

[0013] Among them, the photo-thermal conversion layer catalyst is composed of one or two or more nanomaterials with high light absorption and high photo-thermal conversion efficiency, or is composed of one or two or more doped nanomaterials with high light absorption and high photo-thermal conversion efficiency; the photo-thermal conversion layer catalyst is a nanosemiconductor material and / or a nanometal material; the nanosemiconductor materials include metal nitride nanomaterials; the nanometal materials include a composite material of one or two or more of noble metal nanoparticles, non-noble metal nanoparticles, transition metal nanoparticles, and rare earth metal nanomaterials.

[0014] Among them, the porous carrier is a material with a high specific surface area, high conductivity, and high heat transfer; preferably, the porous carrier is at least one of various materials with a porous morphology such as organic porous materials, porous metal materials, porous semiconductor materials, molecular sieves, porous metal oxides, and metal felts.

[0015] Among them, the thickness of the core layer catalyst is 0.01 - 50 microns, the thickness of the regeneration layer catalyst is 0.01 - 10 microns, the thickness of the first reaction active layer catalyst is 0.01 - 5 microns, the thickness of the second reaction active layer catalyst is 0.01 - 5 microns, and the thickness of the photo-thermal conversion layer catalyst is 0.01 - 50 microns.

[0016] Among them, the layers of the multi-layer composite catalyst are longitudinally arranged in a periodic arrangement or a random arrangement; all layers are in direct contact; the thickness of the same layer is uniform and the material is the same.

[0017] The preparation method of the recyclable photocatalyst / thermocatalyst described above deposits the core layer catalyst on a porous support by physical deposition, and the remaining catalyst layers are deposited in sequence in a longitudinal arrangement; each time a catalyst layer is deposited, it is calcined in a reducing atmosphere.

[0018] The application of the above-mentioned recyclable photocatalyst / thermocatalyst in the photocatalytic reduction of carbon dioxide to hydrocarbon fuels.

[0019] Principle of the invention: In the process of pursuing highly efficient and highly selective photocatalytic / thermocatalytic reduction of carbon dioxide to hydrocarbon fuels, the reparability and stability of the photocatalyst / thermocatalyst should be mainly considered. However, the existing photocatalysts / thermocatalysts cannot simultaneously achieve high efficiency, high selectivity, long lifespan, and renewable performance. In response to this phenomenon, the present invention has invented a new type of multi-layer photocatalyst / thermocatalyst to achieve renewable and cyclic photocatalytic reduction of carbon dioxide to hydrocarbon fuels. The photocatalyst / thermocatalyst of the present invention is a multi-layer photocatalyst / thermocatalyst prepared using a variety of inexpensive catalysts. Among them, the regenerative layer nano-catalyst is a composite nano-material doped with one or more elements. After the doped elements enter the lattice of the matrix material and cause lattice distortion of the matrix material, it can more easily fix the oxidation products, so that the first and second active layer materials can realize the regeneration of the multi-layer photocatalyst under offline conditions.

[0020] Beneficial effects: Compared with the prior art, the present invention has achieved the following remarkable effects: (1) Under continuous illumination in the wavelength range of 300nm - 1500nm where the solar spectrum energy is relatively concentrated, due to the reasonable component arrangement design of the recyclable photocatalyst / thermocatalyst of the present invention, the protection of active sites is realized. It not only has high yield and high selectivity but also has good photocatalytic reduction performance of carbon dioxide even after recyclable regeneration. (2) It overcomes the problems of instability and easy deactivation of traditional photocatalytic materials; under continuous illumination, it can achieve long lifespan, high yield, and high selectivity while realizing the recyclable regeneration of the catalyst; the continuous photocatalytic lifespan of the recyclable catalyst after regeneration exceeds the international level by more than 30%. (3) The design method of the recyclable catalyst can effectively reduce the production cost of the large-scale photocatalytic / thermocatalytic reduction of carbon dioxide process. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the catalyst of the present invention;

[0022] Figure 2 It is a cross-sectional transmission electron micrograph of the catalyst of Example 1 of the present invention;

[0023] Figure 3a: Photocatalytic performance diagram of Ni foam - SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN in Example 1; b: Photocatalytic performance diagram of Ni foam - SrTiO3(La,Cr) / Cu@Ni / TiN in the comparative experiment, c: Light absorption performance diagram of Ni foam - SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN in Example 1. Detailed implementation manners

[0024] The present invention will be further described in detail below.

[0025] Example 1

[0026] As Figure 1 shown, the catalyst material of this example successively includes a porous carrier 1, a core - layer catalyst 2, a regeneration - layer catalyst 3, a first reaction - active - layer catalyst 4, a second reaction - active - layer catalyst 5, a regeneration - layer catalyst 3, and a light - heat conversion - layer catalyst 6 from bottom to top; this example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0027] The first step: Preparation of nano - SrTiO3(La,Cr) catalyst

[0028] Prepared by the hydrothermal method. Dissolve 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate in 25.6 ml of isopropanol solution, and stir at room temperature for 30 min. Then add 22.4 ml of aqueous solution to the above - mentioned mixture, continue to stir for 30 min, and then add 32 ml of 2M KOH methanol solution. After continuous stirring for 30 min, hydrothermal treatment is carried out at 200 °C for 24 h. After the hydrothermal treatment, wash with ultrapure water 5 times and dry to obtain nano - SrTiO3(La,Cr) particles.

[0029] The second step: Preparation of Ce:CaF2 powder

[0030] Mix 3 g of calcium fluoride and 0.9 g of cerium nitrate, and calcine in an argon atmosphere at 300 °C for 3 hours.

[0031] The third step: Preparation of Ni foam - SrTiO3(La,Cr)

[0032] Disperse 0.15 g of SrTiO3(La,Cr) in 7 ml of ethanol. Use the impregnation method to load SrTiO3(La,Cr) onto the cleaned Ni foam, then calcine in air at 500 °C for 3 h, and then transfer to a hydrogen atmosphere and calcine at 300 °C for 3 h.

[0033] Step 4: Preparation of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2

[0034] Deposit the nano fluoride layer Ce:CaF2 on top of Ni foam-SrTiO3(La,Cr) by evaporation coating, with an evaporation coating thickness of 100 nm. Deposit the nano copper layer on top of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 by DC magnetron sputtering, with the nano copper layer thickness of 100 nm. Deposit the nano nickel layer on top of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu by DC magnetron sputtering, with the nano nickel layer thickness of 10 nm. Deposit the nano fluoride layer Ce:CaF2 on top of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni by evaporation coating, with an evaporation coating thickness of 100 nm. Then calcine at 300 °C for 3 h in a hydrogen atmosphere.

[0035] Step 5: Preparation of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN

[0036] Disperse 0.15 g of nano TiN in 7 ml of water, and load the nano TiN particles on top of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 by impregnation method, and then calcine at 300 °C for 3 h in a hydrogen atmosphere.

[0037] Prepare Ni foam-SrTiO3(La,Cr) / Cu@Ni / TiN as a comparative experiment for Example 1.

[0038] From Figure 2 It can be seen that the preparation of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN is successful; from Figure 3 It can be seen that the photocatalytic performance and light absorption performance of the multi-layer composite catalyst including the core layer catalyst, regeneration layer catalyst, first reaction active layer catalyst, second reaction active layer catalyst and photo-thermal conversion layer are excellent in terms of renewable and recyclable.

[0039] The light absorption performance of the nickel foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst at different light irradiation times for the photocatalytic carbon dioxide reduction reaction was tested using a UV-visible-near-infrared spectrophotometer. As the light irradiation time increased, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The fluorescence lifetime of photogenerated carriers of the nickel foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst at different light irradiation times for the photocatalytic carbon dioxide reduction reaction was tested using a fluorescence spectrophotometer. As the light irradiation time increased, the fluorescence lifetime of photogenerated carriers of the catalyst shortened, and the fluorescence lifetime of photogenerated carriers recovered after regeneration.

[0040] Example 2

[0041] The catalyst material of this example sequentially includes a porous support 1, a core layer catalyst 2, a regeneration layer catalyst 3, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, and a photo-thermal conversion layer catalyst 6 from bottom to top; this example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0042] The first step: Preparation of nano-SrTiO3(La,Cr) catalyst

[0043] Prepared by the hydrothermal method. 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate were dissolved in 25.6 ml of isopropanol solution and stirred at room temperature for 30 min. Then, 22.4 ml of aqueous solution was added to the above mixture, and stirring was continued for 30 min. After that, 32 ml of 2M KOH methanol solution was added, and after continuous stirring for 30 min, hydrothermal treatment was carried out at 200 °C for 24 h. After the hydrothermal treatment, it was washed 5 times with ultrapure water and dried to obtain nano-SrTiO3(La,Cr) particles.

[0044] The second step: Preparation of Ce:CaF2 powder

[0045] 2.5 g of calcium fluoride and 0.8 g of cerium nitrate were mixed evenly and calcined in an argon atmosphere at 300 °C for 3 hours.

[0046] The third step: Preparation of nickel foam-SrTiO3(La,Cr)

[0047] 0.05 g of SrTiO3(La,Cr) was dispersed in 7 ml of ethanol. SrTiO3(La,Cr) was loaded onto the cleaned nickel foam by the impregnation method, then calcined in air at 500 °C for 3 h, and then transferred to a hydrogen atmosphere and calcined at 300 °C for 3 h.

[0048] Step 4: Preparation of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni

[0049] The nano fluoride layer Ce:CaF2 was deposited on Ni foam-SrTiO3(La,Cr) by evaporation coating method, and the evaporation coating thickness was 15 nm. The nano copper layer was deposited on Ni foam-SrTiO3(La,Cr) / Ce:CaF2 by DC magnetron sputtering method, and the copper layer thickness was 50000 nm. The nano nickel layer was deposited on Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu by DC magnetron sputtering method, and the nano nickel layer thickness was 10 nm. Then it was calcined at 300 °C for 3 h in hydrogen atmosphere.

[0050] Step 5: Preparation of Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / TiN

[0051] 0.5 g of nano TiN was dispersed in 5 ml of water, and the nano TiN particles were loaded on Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni by impregnation method, and then it was calcined at 300 °C for 3 h in hydrogen atmosphere.

[0052] The light absorption performance of the Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst for different light irradiation times of catalytic carbon dioxide reduction reaction was tested by ultraviolet-visible-near-infrared spectrophotometer. With the extension of light irradiation time, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The photogenerated carrier lifetime of the Ni foam-SrTiO3(La,Cr) / Ce:CaF2 / Cu@Ni / TiN composite catalyst for different light irradiation times of catalytic carbon dioxide reduction reaction was tested by fluorescence spectrophotometer. With the extension of light irradiation time, the photogenerated carrier lifetime of the catalyst shortened, and the photogenerated carrier lifetime recovered after regeneration.

[0053] Example 3

[0054] The catalyst material of this example includes a porous support 1, a core layer catalyst 2, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, a regeneration layer catalyst 3 and a photo-thermal conversion layer catalyst 6 from bottom to top in sequence; this example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0055] Step 1: Preparation of nano SrTiO3(La,Cr) catalyst

[0056] Prepared by hydrothermal method, 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate were dissolved in 25.6 ml of isopropanol solution, and stirred at room temperature for 30 min. Then, 22.4 ml of aqueous solution was added to the above mixture, and stirring was continued for 30 min. After that, 32 ml of 2M KOH methanol solution was added, and stirring was continued for 30 min. Then, hydrothermal treatment was carried out at 200 °C for 24 h. After the hydrothermal treatment, it was washed 5 times with ultrapure water and dried to obtain nano-sized SrTiO3(La,Cr) particles.

[0057] Step 2: Preparation of Ce:CaF2 powder

[0058] 5 g of calcium fluoride and 0.9 g of cerium nitrate were mixed evenly and calcined at 300 °C in an argon atmosphere for 3 hours.

[0059] Step 3: Preparation of nickel foam - SrTiO3(La,Cr)

[0060] 0.9 g of SrTiO3(La,Cr) was dispersed in 7 ml of ethanol, and SrTiO3(La,Cr) was loaded onto the cleaned nickel foam by the impregnation method. Then, it was calcined in air at 500 °C for 3 h, and then transferred to a hydrogen atmosphere and calcined at 300 °C for 3 h.

[0061] Step 4: Preparation of nickel foam - SrTiO3(La,Cr) / Cu@Ni / Ce:CaF2

[0062] The nano-sized copper layer was deposited onto the nickel foam - SrTiO3(La,Cr) by DC magnetron sputtering, and the thickness of the nano-sized copper layer was 10 nm. The nano-sized nickel layer was deposited onto the nickel foam - SrTiO3(La,Cr) / Cu by DC magnetron sputtering, the thickness of the nickel layer was 50000 nm, and the vacuum degree was 9*10 Pa. The nano-sized fluoride layer Ce:CaF2 was deposited onto the nickel foam - SrTiO3(La,Cr) / Cu@Ni by evaporation, and the thickness of the nano-sized fluoride layer was 100 nm. Then, it was calcined in a hydrogen atmosphere at 300 °C for 3 h.

[0063] Step 5: Preparation of nickel foam - SrTiO3(La,Cr) / Cu@Ni / Ce:CaF2 / TiN

[0064] 0.15 g of nano-sized TiN was dispersed in 7 ml of water, and the nano-sized TiN particles were loaded onto the nickel foam - SrTiO3(La,Cr) / Cu@Ni / Ce:CaF2 by the impregnation method. Then, it was calcined in a hydrogen atmosphere at 300 °C for 3 h.

[0065] The light absorption performance of the nickel foam-SrTiO3(La,Cr) / Cu@Ni / Ce:CaF2 / TiN composite catalyst for different photocatalytic carbon dioxide reduction reaction times was tested using a UV-Vis-NIR spectrophotometer. As the illumination time increased, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The fluorescence lifetime of the nickel foam-SrTiO3(La,Cr) / Cu@Ni / Ce:CaF2 / TiN composite catalyst for different photocatalytic carbon dioxide reduction reaction times was tested using a fluorescence spectrophotometer. As the illumination time increased, the fluorescence lifetime of the catalyst decreased, and the fluorescence lifetime recovered after regeneration.

[0066] Example 4

[0067] The catalyst material of this example sequentially includes a porous support 1, a core layer catalyst 2, a regeneration layer catalyst 3, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, a regeneration layer catalyst 3, and a photo-thermal conversion layer catalyst 6 from bottom to top; this example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0068] The first step: Preparation of nickel foam-TiO2 catalyst

[0069] Using the DC magnetron sputtering method, a 1 μm thick metal Ti film was deposited on nickel foam using a 99.995% Ti target to obtain a nickel foam-Ti composite catalyst. Then, 100 ml of the nickel foam-Ti composite catalyst was subjected to hydrothermal reaction in a 1 mol / L NaOH autoclave at 180 °C for 24 hours. Then, the precursor was calcined at 500 °C for 3 hours to finally obtain a nickel foam-TiO2 catalyst.

[0070] The second step: Preparation of Ce:CaF2 powder

[0071] 0.12 g of calcium fluoride and 0.91414 g of cerium nitrate were mixed evenly and calcined in an argon atmosphere at 300 °C for 3 hours.

[0072] The third step: Preparation of nickel foam-TiO2 / Ce:CaF2 / Cu@Ni / Ce:CaF2

[0073] The nano fluoride layer Ce:CaF2 was deposited onto nickel foam - TiO2 by evaporation coating method, with an evaporation coating thickness of 100 nm. The nano copper layer was deposited onto nickel foam - TiO2 / Ce:CaF2 by DC magnetron sputtering method, with a nano copper layer thickness of 100 nm. The nano nickel layer was deposited onto nickel foam - TiO2 / Ce:CaF2 / Cu by DC magnetron sputtering method, with a nano nickel layer thickness of 1000 nm. The nano fluoride layer Ce:CaF2 was deposited onto nickel foam - TiO2 / Ce:CaF2 / Cu@Ni by evaporation coating method, with an evaporation coating thickness of 100 nm. Then it was calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0074] Step 5: Preparation of nickel foam - TiO2 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN

[0075] 0.15 g of nano TiN was dispersed in 7 ml of water, and the nano TiN particles were loaded onto nickel foam - TiO2 / Ce:CaF2 / Cu@Ni / Ce:CaF2 by impregnation method, and then calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0076] The light absorption performance of the nickel foam - TiO2 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst at different light - catalyzed carbon dioxide reduction reaction times was tested using a UV - Vis - NIR spectrophotometer. As the light - irradiation time extended, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The photogenerated carrier lifetime of the nickel foam - TiO2 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst at different light - catalyzed carbon dioxide reduction reaction times was tested using a fluorescence spectrophotometer. As the light - irradiation time extended, the photogenerated carrier lifetime of the catalyst shortened, and the photogenerated carrier lifetime recovered after regeneration.

[0077] Example 5

[0078] The catalyst material of this example includes, from bottom to top, a porous support 1, a core - layer catalyst 2, a regeneration - layer catalyst 3, a first reaction - active - layer catalyst 4, a second reaction - active - layer catalyst 5, a regeneration - layer catalyst 3, and a light - heat conversion - layer catalyst 6. This example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0079] Step 1: Preparation of nano carbon nitride catalyst

[0080] It was prepared by thermal etching method. 1 g of urea was dispersed in 10 ml of 2 mol / L dilute hydrochloric acid solution and soaked for 0.5 h, and then calcined at 500 °C for 2 h. Layered graphite - phase carbon nitride nanoparticles can be obtained.

[0081] Step 2: Preparation of Ce:CaF2 powder

[0082] Mix 3 g of calcium fluoride and 1 g of cerium nitrate evenly and calcine them in an argon atmosphere at 300 °C for 3 hours.

[0083] Step 3: Preparation of nickel foam - g-C3N4

[0084] Disperse 0.15 g of g-C3N4 in 7 ml of ultrapure water, and use the impregnation method to load g-C3N4 onto the cleaned nickel foam, and then calcine it in an argon atmosphere at 500 °C for 3 h.

[0085] Step 4: Preparation of nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni / Ce:CaF2

[0086] Deposit the nano fluoride layer Ce:CaF2 onto nickel foam - g-C3N4 by evaporation coating, with an evaporation coating thickness of 100 nm.Deposit the nano copper layer onto nickel foam - g-C3N4 / Ce:CaF2 by DC magnetron sputtering, with a nano copper layer thickness of 100 nm.Deposit the nano nickel layer onto nickel foam - g-C3N4 / Ce:CaF2 / Cu by DC magnetron sputtering, with a nano nickel layer thickness of 10 nm.Deposit the nano fluoride layer Ce:CaF2 onto nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni by evaporation coating, with an evaporation coating thickness of 100 nm.Then calcine it in a hydrogen atmosphere at 300 °C for 3 h.

[0087] Step 5: Preparation of nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN

[0088] Disperse 0.1 g of nano TiN in 7 ml of water, and use the impregnation method to load the nano TiN particles onto nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni / Ce:CaF2, and then calcine it in a hydrogen atmosphere at 300 °C for 3 h.

[0089] Use a UV-Vis-NIR spectrophotometer to test the light absorption performance of the nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst for different light irradiation times in the photocatalytic reduction of carbon dioxide. As the light irradiation time prolongs, the light absorption performance of the catalyst decreases, and the light absorption performance recovers after regeneration.Use a fluorescence spectrophotometer to test the photogenerated carrier lifetime of the nickel foam - g-C3N4 / Ce:CaF2 / Cu@Ni / Ce:CaF2 / TiN composite catalyst for different light irradiation times in the photocatalytic reduction of carbon dioxide. As the light irradiation time prolongs, the photogenerated carrier lifetime of the catalyst shortens, and the photogenerated carrier lifetime recovers after regeneration.

[0090] Example 6

[0091] The catalyst material of this embodiment sequentially includes a porous support 1, a core layer catalyst 2, a regeneration layer catalyst 3, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, a regeneration layer catalyst 3, and a photo-thermal conversion layer catalyst 6 from bottom to top; this embodiment provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0092] Step 1: Preparation of nano-carbon nitride catalyst

[0093] It is prepared by the thermal etching method. 1 g of urea is dispersed in 10 ml of 2 mol / L dilute hydrochloric acid solution and soaked for 0.5 h, and then calcined at 500 °C for 2 h. Layered graphite-phase carbon nitride nanoparticles can be obtained.

[0094] Step 2: Preparation of Ce:CaF2 powder

[0095] 4.8 g of calcium fluoride and 0.5 g of cerium nitrate are mixed evenly and calcined in an argon atmosphere at 300 °C for 3 hours.

[0096] Step 3: Preparation of nickel foam - g-C3N4

[0097] 0.15 g of g-C3N4 is dispersed in 7 ml of ultrapure water, and g-C3N4 is loaded onto the cleaned nickel foam by the impregnation method, and then at 500 °C for 3 h in an argon atmosphere.

[0098] Step 4: Preparation of nickel foam - g-C3N4 / Ce:CaF2 / Au@Ni / Ce:CaF2

[0099] The nano-fluoride layer Ce:CaF2 is deposited onto nickel foam - g-C3N4 by evaporation coating with a coating thickness of 100 nm. The nano-gold layer is deposited onto nickel foam - g-C3N4 / Ce:CaF2 by DC magnetron sputtering, with the nano-gold layer thickness of 100 nm and the vacuum degree of 9*10 Pa. The nano-nickel layer is deposited onto nickel foam - g-C3N4 / Ce:CaF2 / Au by DC magnetron sputtering, with the nano-nickel layer thickness of 10 nm. The nano-fluoride layer Ce:CaF2 is deposited onto nickel foam - g-C3N4 / Ce:CaF2 / Au@Ni by evaporation coating with a coating thickness of 1000 nm. Then it is calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0100] Step 5: Preparation of nickel foam - g-C3N4 / Ce:CaF2 / Au@Ni / Ce:CaF2 / TiN

[0101] Disperse 0.15 g of nano-TiN in 3 ml of water, and use the impregnation method to load the nano-TiN particles onto the foam nickel-g-C3N4 / Ce:CaF2 / Au@Ni / Ce:CaF2, and then calcine at 300 °C for 3 h under a hydrogen atmosphere.

[0102] Use a UV-visible-near-infrared spectrophotometer to test the light absorption performance of the foam nickel-g-C3N4 / Ce:CaF2 / Au@Ni / Ce:CaF2 / TiN composite catalyst at different light irradiation times for the photocatalytic reduction of carbon dioxide. As the light irradiation time prolongs, the light absorption performance of the catalyst decreases, and the light absorption performance recovers after regeneration. Use a fluorescence spectrophotometer to test the photogenerated carrier lifetime of the foam nickel-g-C3N4 / Ce:CaF2 / Au@Ni / Ce:CaF2 / TiN composite catalyst at different light irradiation times for the photocatalytic reduction of carbon dioxide. As the light irradiation time prolongs, the photogenerated carrier lifetime of the catalyst shortens, and the photogenerated carrier lifetime recovers after regeneration.

[0103] Example 7

[0104] The catalyst material of this example sequentially includes a porous support 1, a core layer catalyst 2, a regeneration layer catalyst 3, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, a regeneration layer catalyst 3, and a photo-thermal conversion layer catalyst 6 from bottom to top; this example provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0105] The first step: Preparation of nano-SrTiO3(La,Cr) catalyst

[0106] Prepared by the hydrothermal method. Dissolve 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate in 25.6 ml of isopropanol solution, and stir at room temperature for 30 min. Then add 22.4 ml of aqueous solution to the above mixture, continue to stir for 30 min, and then add 32 ml of 2M KOH methanol solution. After continuous stirring for 30 min, hydrothermal reaction is carried out at 200 °C for 24 h. After the hydrothermal reaction is completed, wash with ultrapure water 5 times and dry to obtain nano-SrTiO3(La,Cr) particles.

[0107] The second step: Preparation of Ce:CaF2 powder

[0108] Mix 4 g of calcium fluoride and 0.9 g of cerium nitrate, and calcine at 300 °C in an argon atmosphere for 3 hours.

[0109] The third step: Preparation of foam nickel-SrTiO3(La,Cr)

[0110] Disperse 0.9 g of SrTiO3(La,Cr) in 7 ml of ethanol. Use the impregnation method to load SrTiO3(La,Cr) onto the cleaned nickel foam, then calcine it in air at 500 °C for 3 h, and then transfer it to a hydrogen atmosphere and calcine it at 300 °C for 3 h.

[0111] Step 4: Preparation of nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu / Ce:CaF2

[0112] Deposit the nano - fluoride layer Ce:CaF2 onto nickel foam - SrTiO3(La,Cr) by evaporation coating with a thickness of 100 nm. Deposit the nano - silver layer onto nickel foam - SrTiO3(La,Cr) / Ce:CaF2 by DC magnetron sputtering with a nano - gold layer thickness of 100 nm. Deposit the nano - copper layer onto nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag by DC magnetron sputtering with a nano - copper layer thickness of 10 nm. Deposit the nano - fluoride layer Ce:CaF2 onto nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu by evaporation coating with a thickness of 1000 nm. Then calcine it in a hydrogen atmosphere at 300 °C for 3 h.

[0113] Step 5: Preparation of nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu / Ce:CaF2 / TiN

[0114] Disperse 0.15 g of nano - TiN in 3 ml of water. Use the impregnation method to load the nano - TiN particles onto nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu / Ce:CaF2, and then calcine it in a hydrogen atmosphere at 300 °C for 3 h.

[0115] Use a UV - Vis - NIR spectrophotometer to test the light absorption performance of the nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu / Ce:CaF2 / TiN composite catalyst at different light - induced catalytic carbon dioxide reduction reaction times. As the light - irradiation time prolongs, the light absorption performance of the catalyst decreases, and the light absorption performance recovers after regeneration. Use a fluorescence spectrophotometer to test the photogenerated carrier lifetime of the nickel foam - SrTiO3(La,Cr) / Ce:CaF2 / Ag@Cu / Ce:CaF2 / TiN composite catalyst at different light - induced catalytic carbon dioxide reduction reaction times. As the light - irradiation time prolongs, the photogenerated carrier lifetime of the catalyst shortens, and the photogenerated carrier lifetime recovers after regeneration.

[0116] Example 8

[0117] The catalyst material of this embodiment sequentially includes a porous support 1, a core layer catalyst 2, a regeneration layer catalyst 3, a first reaction active layer catalyst 4, a second reaction active layer catalyst 5, a regeneration layer catalyst 3, and a photo-thermal conversion layer catalyst 6 from bottom to top; this embodiment provides a preparation method of a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0118] Step 1: Preparation of nano-SrTiO3(La,Cr) catalyst

[0119] Prepared by the hydrothermal method. Dissolve 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate in 25.6 ml of isopropanol solution, stir at room temperature for 30 min, then add 22.4 ml of aqueous solution to the above mixture, continue to stir for 30 min, and then add 32 ml of 2M KOH methanol solution. After continuous stirring for 30 min, hydrothermal treatment is carried out at 200 °C for 24 h. After the hydrothermal treatment, wash with ultrapure water 5 times and dry to obtain nano-SrTiO3(La,Cr) particles.

[0120] Step 2: Preparation of Ba La:MgF2 powder

[0121] Mix 4 g of magnesium fluoride, 0.3 g of lanthanum nitrate, and 0.4 g of barium nitrate, and calcine in an argon atmosphere at 300 °C for 3 hours.

[0122] Step 3: Preparation of nickel foam-SrTiO3(La,Cr)

[0123] Disperse 0.9 g of SrTiO3(La,Cr) in 7 ml of ethanol. Use the impregnation method to load SrTiO3(La,Cr) onto the cleaned nickel foam, then burn in air at 500 °C for 3 h, and then transfer to a hydrogen atmosphere and calcine at 300 °C for 3 h.

[0124] Step 4: Preparation of nickel foam-SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / Ce:CaF2

[0125] The nano fluoride layer Ba La:MgF2 was deposited onto nickel foam - SrTiO3(La,Cr) by evaporation coating method with a coating thickness of 100 nm. The nano gold layer was deposited onto nickel foam - SrTiO3(La,Cr) / BaLa:MgF2 by DC magnetron sputtering method, and the nano silver layer had a thickness of 100 nm. The nano copper layer was deposited onto nickel foam - SrTiO3(La,Cr) / BaLa:MgF2 / Ag by DC magnetron sputtering method, and the nano nickel layer had a thickness of 10 nm. The nano fluoride layer Ba La:MgF2 was deposited onto nickel foam - SrTiO3(La,Cr) / Ba La:MgF2 / Ag@Cu by evaporation coating method with a coating thickness of 1000 nm. Then it was calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0126] Step 5: Preparation of nickel foam - SrTiO3(La,Cr) / Ba La:MgF2 / Ag@Cu / Ba La:MgF2 / TiN

[0127] 0.15 g of nano TiN was dispersed in 3 ml of water, and the nano TiN particles were loaded onto nickel foam - SrTiO3(La,Cr) / Ba La:MgF2 / Ag@Cu / Ba La:MgF2 by impregnation method, and then calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0128] The light absorption performance of the nickel foam - SrTiO3(La,Cr) / Ba La:MgF2 / Ag@Cu / Ba La:MgF2 / TiN composite catalyst at different light - induced catalytic carbon dioxide reduction reaction times was tested using a UV - Vis - NIR spectrophotometer. As the light irradiation time increased, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The photogenerated carrier lifetime of the nickel foam - SrTiO3(La,Cr) / Ba La:MgF2 / Ag@Cu / BaLa:MgF2 / TiN composite catalyst at different light - induced catalytic carbon dioxide reduction reaction times was tested using a fluorescence spectrophotometer. As the light irradiation time increased, the photogenerated carrier lifetime of the catalyst shortened, and the photogenerated carrier lifetime recovered after regeneration.

[0129] Example 9

[0130] The catalyst material of this example includes, from bottom to top in sequence, a porous support 1, a core - layer catalyst 2, a regeneration - layer catalyst 3, a first reaction - active - layer catalyst 4, a second reaction - active - layer catalyst 5, a regeneration - layer catalyst 3, and a light - heat conversion - layer catalyst 6; this example provides a preparation method for a recyclable and regenerable photo / thermal catalyst with a long catalytic life, including the following steps:

[0131] Step 1: Preparation of nano SrTiO3(La,Cr) catalyst

[0132] Prepared by hydrothermal method. 1.0652 g of strontium acetate, 0.8456 g of isopropyl titanate, 0.06146 g of chromium nitrate, and 0.06651 g of lanthanum nitrate were dissolved in 25.6 ml of isopropanol solution, and stirred at room temperature for 30 min. Then, 22.4 ml of aqueous solution was added to the above mixture, and stirred continuously for 30 min. After that, 32 ml of 2M KOH methanol solution was added, and stirred continuously for 30 min. Then, hydrothermal treatment was carried out at 200 °C for 24 h. After the hydrothermal treatment, it was washed 5 times with ultrapure water and dried to obtain nano SrTiO3(La,Cr) particles.

[0133] Step 2: Preparation of La:MgF2 powder

[0134] 4 g of magnesium fluoride and 0.9 g of lanthanum nitrate were mixed evenly and calcined at 300 °C in an argon atmosphere for 3 hours.

[0135] Step 3: Preparation of nickel foam - SrTiO3(La,Cr)

[0136] 0.9 g of SrTiO3(La,Cr) was dispersed in 7 ml of ethanol. SrTiO3(La,Cr) was loaded onto the cleaned nickel foam by the impregnation method, and then calcined in air at 500 °C for 3 h, and then transferred to a hydrogen atmosphere and calcined at 300 °C for 3 h.

[0137] Step 4: Preparation of nickel foam - SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / Ce:CaF2

[0138] The nano - fluoride layer La:MgF2 was deposited onto nickel foam - SrTiO3(La,Cr) by evaporation coating with a thickness of 100 nm. The nano - gold layer was deposited onto nickel foam - SrTiO3(La,Cr) / La:MgF2 by DC magnetron sputtering with a thickness of 100 nm for the nano - silver layer. The nano - copper layer was deposited onto nickel foam - SrTiO3(La,Cr) / La:MgF2 / Ag by DC magnetron sputtering with a thickness of 10 nm for the nano - nickel layer. The nano - fluoride layer La:MgF2 was deposited onto nickel foam - SrTiO3(La,Cr) / La:MgF2 / Ag@Cu by evaporation coating with a thickness of 1000 nm. Then, it was calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0139] Step 5: Preparation of nickel foam - SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / La:MgF2 / Au

[0140] The nano-gold layer was deposited onto the nickel foam-SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / La:MgF2 by DC magnetron sputtering method, and the thickness of the nano-gold layer was 10 nm. Then it was calcined at 300 °C for 3 h in a hydrogen atmosphere.

[0141] The nickel foam-SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / La:MgF2 / Au composite catalyst with different photocatalytic carbon dioxide reduction reaction times was tested for its light absorption performance using a UV-Vis-NIR spectrophotometer. As the illumination time extended, the light absorption performance of the catalyst decreased, and the light absorption performance recovered after regeneration. The nickel foam-SrTiO3(La,Cr) / La:MgF2 / Ag@Cu / La:MgF2 / Au composite catalyst with different photocatalytic carbon dioxide reduction reaction times was tested for the lifetime of photo-generated carriers using a fluorescence spectrophotometer. As the illumination time extended, the lifetime of photo-generated carriers of the catalyst shortened, and the lifetime of photo-generated carriers recovered after regeneration.

Claims

1. A recyclable photocatalyst / thermal catalyst, characterized in that, It includes a porous support (1) and a multi-layer composite catalyst supported on the porous support (1). The multi-layer composite catalyst includes a core layer catalyst (2), a regeneration layer catalyst (3), a first reaction active layer catalyst (4), a second reaction active layer catalyst (5), and a photo-thermal conversion layer catalyst (6). The layers of the multi-layer composite catalyst are arranged longitudinally, and the catalysts in adjacent layers are different. The core layer catalyst (2) is in direct contact with the porous support (1).

2. The recyclable photocatalyst / thermal catalyst according to claim 1, wherein The core layer catalyst (2), the regeneration layer catalyst (3), the first reaction active layer catalyst (4), and the second reaction active layer catalyst (5) are each composed of one, multiple, or doped nano-material composites.

3. The recyclable photocatalyst / thermal catalyst according to claim 1, wherein The photo-thermal conversion layer catalyst (6) is composed of one, multiple, or doped nano-material composites with high light absorption and high photo-thermal conversion efficiency.

4. The recyclable photocatalyst / thermal catalyst according to claim 1, characterized in that, The core layer catalyst (2), the regeneration layer catalyst (3), the first reaction active layer catalyst (4), and the second reaction active layer catalyst (5) are each one or more composite materials among nano-semiconductor materials and nano-metal materials.

5. The recyclable photo / thermal catalyst according to claim 4, characterized in that, The core layer catalyst (2) includes a composite material of one or two or more of perovskite-type nano-materials, metal oxide nano-materials, and non-metal carbon and nitride nano-materials.

6. The recyclable photocatalyst / thermal catalyst according to claim 4, wherein The regeneration layer catalyst (3) is a composite nano-material of metal fluoride doped with at least one element.

7. The recyclable photo / thermal catalyst according to claim 4, wherein The first reaction active layer catalyst (4) and the second reaction active layer catalyst (5) are at least one of MOFs, COFs nano-materials, or nano-metal materials. The nano-metal materials include a composite material of one or two or more of noble metal nano-materials, non-noble metal nano-materials, transition metal nano-materials, and rare earth metal nano-materials.

8. The recyclable photocatalyst / thermal catalyst according to claim 1, characterized in that, The photo-thermal conversion layer catalyst (6) is nano-semiconductor material and / or nano-metal material. The nano-semiconductor materials include metal nitride nano-materials. The nano-metal materials include a composite material of one or two or more of noble metal nano-particles, non-noble metal nano-particles, transition metal nano-particles, and rare earth metal nano-materials.

9. The recyclable photocatalyst / thermal catalyst according to claim 1, wherein The porous support (1) is at least one of organic porous materials, porous metal materials, porous semiconductor materials, molecular sieves, porous metal oxides, and metal felts.

10. The recyclable photocatalyst / thermal catalyst according to claim 1, characterized in that, The thickness of the core layer catalyst (2) is 0.01 - 50 microns, the thickness of the regeneration layer catalyst (3) is 0.01 - 10 microns, the thickness of the first reaction active layer catalyst (4) is 0.01 - 5 microns, the thickness of the second reaction active layer catalyst (5) is 0.01 - 5 microns, and the thickness of the photo-thermal conversion layer catalyst (6) is 0.01 - 50 microns.

11. The recyclable photocatalyst / thermal catalyst according to claim 1, wherein The layers of the multi-layer composite catalyst are arranged longitudinally in a periodic arrangement or a random arrangement.

12. The preparation method of the recyclable photo / thermal catalyst according to claim 1, characterized in that, The core layer catalyst (2) is deposited on the porous support (1) by physical deposition, and the remaining layer catalysts are deposited in sequence according to the longitudinal arrangement. Each deposition of a layer of catalyst is calcined in a reducing atmosphere.

13. Application of the recyclable and regenerable photo / thermal catalyst according to claim 1 in the photoreduction of carbon dioxide to produce hydrocarbon fuels.

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