A photocatalyst containing multiple metal elements, and a preparation method and application thereof

Abstract

The application discloses a kind of photocatalyst containing multiple metal elements and its preparation method and application, comprising two or more metal elements, the metal element exists in the form of metal element, alloy, intermetallic compound, metal oxide, composite metal oxide, metal sulfide, metal nitride, metal phosphide, metal carbide or its composite, the catalyst contains multiple metal elements, simultaneously has the characteristics of simple process, composition uniformity controllable, structure stable and suitable for scale, can overcome the problems such as large solvent consumption, cumbersome post-processing, uneven component dispersion, composition control difficulty and not conducive to scale preparation in existing liquid phase or semi-liquid phase preparation method.

Description

Technical Field

[0001] This invention belongs to the field of photocatalytic material preparation technology, and relates to a photocatalyst containing multiple metal elements, its preparation method and application. Background Technology

[0002] With the increasing prominence of energy shortages and environmental pollution, photocatalysis, a technology that utilizes solar energy to drive chemical reactions, has attracted widespread attention from academia and industry due to its advantages such as cleanliness, sustainability, and mild reaction conditions. Photocatalysis generally refers to the process in which a catalyst absorbs photon energy and generates photogenerated electrons and holes under light conditions, thereby driving chemical reactions such as water splitting to produce hydrogen, carbon dioxide reduction, nitrogen fixation, degradation of organic pollutants, and organic synthesis. It is an important pathway to convert solar energy into chemical energy.

[0003] As the core material in photocatalytic processes, the composition, structure, and preparation method of photocatalytic reactions directly affect their activity, selectivity, and stability. In recent years, photocatalysts containing multiple metal elements have shown significant application potential in the field of photocatalysis due to their advantages such as large compositional control space, tunable electronic structure, abundant active sites, and good structural stability. These catalysts can include multi-metal alloys, intermetallic compounds, composite metal oxides, medium- or high-entropy metal-based materials, as well as various material systems such as metal sulfides, metal nitrides, metal phosphides, and metal carbides. By introducing two or more metal elements, the light absorption capacity, carrier separation and migration behavior, surface reactivity, and structural stability of the material can be controlled, thereby improving its overall performance in different photocatalytic reactions. Therefore, photocatalysts containing multiple metal elements have become one of the important directions in current photocatalytic materials research.

[0004] Currently, photocatalysts containing multiple metal elements can typically be prepared using liquid-phase or semi-liquid-phase methods such as co-precipitation, sol-gel, hydrothermal, solvothermal, impregnation, deposition, and spray pyrolysis. These methods are widely used in laboratory research, but they also have certain limitations. For example, some liquid-phase methods require large amounts of solvents, complexing agents, precipitants, or surfactants, making the preparation and post-processing processes cumbersome. In multi-metal component systems, the solubility, hydrolysis rate, precipitation behavior, and coordination ability of different metal precursors vary, easily leading to component segregation, deviations from design values, or localized structural inhomogeneities. Furthermore, the liquid-phase preparation process may generate waste liquid, increasing subsequent treatment costs and hindering large-scale production.

[0005] The all-solid-state reaction method refers to a method that uses solid raw materials as precursors and, through mechanical mixing, grinding, ball milling, solid-state treatment, and subsequent processing, enables the components to contact, diffuse, react, undergo phase transformation, or structural reconstruction under solid-state conditions, thereby forming the target material. Compared with liquid-phase preparation methods, the all-solid-state reaction method has advantages such as a relatively simple process flow, no or significantly reduced solvent use, direct component introduction, lower environmental impact, and suitability for large-scale preparation. It is particularly suitable for the preparation of multi-metallic elements, composite metal oxides, alloys, intermetallic compounds, and other composite catalytic materials.

[0006] However, existing solid-phase synthesis methods still have certain limitations when used to prepare photocatalysts containing multiple metal elements. For example, the limited contact between different solid precursors may lead to insufficient solid-phase diffusion; some systems are prone to problems such as uneven component distribution, crystal phase separation, or local sintering during processing; at the same time, parameters such as solid-phase processing temperature, atmosphere, processing time, heating and cooling rates, and post-processing methods have a significant impact on the composition, crystal structure, particle morphology, and catalytic performance of the final catalyst. Therefore, developing a simple, uniformly controllable, structurally stable, and scalable all-solid-state reaction preparation method for photocatalysts containing multiple metal elements has significant research value and application significance. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a photocatalyst containing multiple metal elements, its preparation method and application. The catalyst contains multiple metal elements and has the characteristics of simple process, uniform and controllable composition, stable structure and suitability for large-scale preparation. It can overcome the problems of large solvent consumption, cumbersome post-processing, uneven component dispersion, difficulty in composition control and unfavorable to large-scale preparation in existing liquid phase or semi-liquid phase preparation methods.

[0008] To achieve the above objectives, the present invention discloses a photocatalyst containing multiple metal elements, comprising two or more metal elements, wherein the metal elements exist in the form of elemental metals, alloys, intermetallic compounds, metal oxides, composite metal oxides, metal sulfides, metal nitrides, metal phosphides, metal carbides, or complexes thereof.

[0009] Furthermore, the metal element is a transition metal element, a main group metal element, or a rare earth metal element.

[0010] This invention discloses a method for preparing a photocatalyst containing multiple metal elements, comprising the following steps: 1) Using two or more metal-containing solid substances as precursors, mechanically mix them in a predetermined ratio to obtain precursor powder; 2) The precursor powder is placed in a reaction vessel for solid-state treatment, so that different components undergo diffusion, reaction, crystal phase transformation or structural reconstruction under solid-state conditions; 3) The product obtained in step 2) is post-processed to obtain a photocatalyst containing multiple metal elements.

[0011] Furthermore, solid substances containing metals include one or more of the following: metal salts, metal oxides, elemental metals, metal hydroxides, metal carbonates, metal nitrates, metal chlorides, metal sulfates, organometallic salts, metal sulfides, metal nitrides, metal phosphides, and metal carbides.

[0012] Furthermore, the precursor also contains a non-metallic component, which is one or more of a sulfur source, nitrogen source, phosphorus source, carbon source, boron source, selenium source, tellurium source or halogen source.

[0013] Furthermore, the mechanical mixing method is one or a combination of two or more of the following: grinding, ball milling, stirring, three-dimensional mixing, vibration mixing, rotational mixing, sand milling, and ultrasonic mixing.

[0014] Furthermore, the solid-phase treatment temperature is 20–2000 °C, and the treatment time is 0.1–100 h. By adjusting the treatment temperature, treatment time, heating rate, cooling rate, and treatment atmosphere, the elemental distribution, crystal phase composition, particle morphology, defect structure, and catalytic performance of the obtained photocatalyst can be controlled.

[0015] Furthermore, the solid-state treatment method is one or a combination of two or more of the following: muffle furnace treatment, tube furnace treatment, box furnace treatment, pit furnace treatment, rotary furnace treatment, fluidized bed treatment, hot pressing sintering, spark plasma sintering, microwave treatment, induction heating treatment, laser treatment, infrared treatment, and electric arc melting.

[0016] Furthermore, the atmosphere for the solid-phase treatment is one or a combination of two or more of the following: air, oxygen, nitrogen, argon, helium, hydrogen, ammonia, carbon monoxide, carbon dioxide, methane, water vapor, or vacuum.

[0017] This invention discloses the application of a photocatalyst containing multiple metal elements in photocatalytic reactions.

[0018] The present invention has the following beneficial effects: The photocatalyst containing multiple metal elements described in this invention, along with its preparation method and application, employs an all-solid-state reaction preparation method, eliminating the need for complex liquid-phase reaction processes. This reduces or avoids the use of large amounts of solvents, precipitants, complexing agents, and surfactants, thus lowering the environmental burden during the preparation process. Furthermore, this invention allows for direct control of the types and proportions of different metal elements through the weighing and mechanical mixing of solid precursors, facilitating controllable preparation of the photocatalyst composition. The combination of mechanical mixing and solid-phase treatment enables diffusion, reaction, crystal phase transformation, or structural reconstruction of different components under solid-state conditions, improving the catalyst's compositional uniformity, crystal phase stability, and component bonding strength. The preparation process is simple, the equipment is widely applicable, and it is suitable for scale-up preparation and large-scale production. It is applicable to various metal-containing solid precursors and non-metallic components, and can be used to prepare alloys, intermetallic compounds, metal oxides, composite metal oxides, metal sulfides, metal nitrides, metal phosphides, metal carbides, and their composite photocatalysts containing multiple metal elements. It has a wide range of applications and is highly practical. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 The X-ray diffraction (XRD) pattern of the multi-component metal photocatalyst NiTiCaO prepared in Example 5.

[0021] Figure 2 The UV-Vis-NIR diffuse reflectance spectrum of the multi-component metal photocatalyst NiTiCaO prepared in Example 5 is shown. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0024] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0025] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0026] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0027] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0030] The photocatalyst containing multiple metal elements of the present invention comprises two or more metal elements, wherein the metal elements exist in the form of elemental metals, alloys, intermetallic compounds, metal oxides, composite metal oxides, metal sulfides, metal nitrides, metal phosphides, metal carbides or their complexes, and the photocatalyst can participate in or promote photocatalytic reactions under light irradiation conditions.

[0031] In this embodiment, the metal element includes two or more of transition metals, main group metals and rare earth metals. Different metal elements can be used as light absorption regulating components, catalytic active components, structural stabilizing components or electron transfer regulating components in the photocatalyst, thereby regulating the light absorption capacity, carrier separation and migration behavior, surface reaction activity and structural stability of the photocatalyst.

[0032] The all-solid-state reaction preparation method of the photocatalyst containing multiple metal elements of the present invention includes the following steps: using two or more metal-containing solid substances as precursors, mechanically mixing to make the components uniformly contact and disperse under solid-state conditions, followed by solid-state treatment to allow different components to diffuse, react, undergo crystal phase transformation or structural reconstruction under solid-state conditions, and finally cooling and post-treatment to obtain the photocatalyst containing multiple metal elements.

[0033] Specifically, the following steps are included: 1) Using two or more metal-containing solid substances as precursors, mechanically mix them in a predetermined ratio to obtain a mixed precursor; 2) The mixed precursor is placed in a reaction vessel for solid-state treatment, so that different components undergo diffusion, reaction, crystal phase transformation or structural reconstruction under solid-state conditions; 3) The product obtained in step 2) is post-processed to obtain a photocatalyst containing multiple metal elements.

[0034] In this embodiment, the post-processing is one or a combination of cooling, crushing, grinding, washing, drying or sieving.

[0035] In this embodiment, the process of placing the mixed precursors in a reaction vessel for solid-state treatment is as follows: under conditions where a liquid-phase reaction system is not the primary reaction medium, a process is initiated in which the mixed precursors undergo contact, diffusion, reaction, crystal phase transformation, structural reconstruction, or component bonding. The solid-state treatment includes, but is not limited to, low-temperature solid-state treatment, solid-state heat treatment, sintering, hot-pressing sintering, spark plasma sintering, microwave treatment, induction heating treatment, laser treatment, infrared treatment, or arc melting.

[0036] In this embodiment, the metal-containing solid substance includes one or more of the following: metal salt, metal oxide, elemental metal, metal hydroxide, metal carbonate, metal nitrate, metal chloride, metal sulfate, organometallic salt, metal sulfide, metal nitride, metal phosphide, and metal carbide.

[0037] In this embodiment, the precursor further comprises a non-metallic component, which is one or more of the following: sulfur source, nitrogen source, phosphorus source, carbon source, boron source, selenium source, tellurium source, and halogen source.

[0038] In this embodiment, the mechanical mixing method is one or a combination of two or more of the following: grinding, ball milling, stirring, three-dimensional mixing, vibration mixing, rotational mixing, sand milling, and ultrasonic mixing.

[0039] In this embodiment, the solid-phase treatment temperature is 20–2000 °C, and the treatment time is 0.1–100 h. By adjusting the treatment temperature, treatment time, heating rate, cooling rate, and treatment atmosphere, the elemental distribution, crystal phase composition, particle morphology, defect structure, and catalytic performance of the obtained photocatalyst can be controlled.

[0040] In this embodiment, the solid-phase treatment method is one or a combination of two or more of the following: muffle furnace treatment, tube furnace treatment, box furnace treatment, pit furnace treatment, rotary furnace treatment, fluidized bed treatment, hot pressing sintering, spark plasma sintering, microwave treatment, induction heating treatment, laser treatment, infrared treatment, and electric arc melting.

[0041] In this embodiment, the atmosphere for the solid phase treatment is one or a combination of two or more of the following: air, oxygen, nitrogen, argon, helium, hydrogen, ammonia, carbon monoxide, carbon dioxide, methane, water vapor, and vacuum.

[0042] This invention relates to the application of a photocatalyst containing multiple metal elements in photocatalytic reactions. The photocatalytic reactions include one or more of the following: photocatalytic water splitting for hydrogen production, photocatalytic oxygen production, photocatalytic carbon dioxide reduction, photocatalytic nitrogen reduction for ammonia synthesis, photocatalytic degradation of organic pollutants, photocatalytic selective oxidation of organic matter, or photocatalytic selective reduction of organic matter. The photocatalytic selective oxidation or reduction of organic matter may include the selective transformation of alcohols, aldehydes, amines, aromatic compounds, or other organic substrates.

[0043] Example 1 This embodiment discloses a method for preparing a Cu-Fe composite oxide photocatalyst containing multiple metal elements, including the following steps: 1) Using copper oxide (CuO) and ferric oxide (Fe2O3) as solid precursors, the raw material powders weighed according to the molar ratio of Cu:Fe = 1:2 were placed in a planetary ball mill jar, and zirconium oxide grinding balls were added. The ball-to-material ratio was 10:1. The mixture was ball-milled at a speed of 400 r / min for 6 h to obtain a uniformly mixed precursor powder.

[0044] 2) The precursor powder is transferred to a corundum crucible and placed in a tube furnace. Under an air atmosphere, the temperature is increased to 800 °C at a heating rate of 5 °C / min and held for 4 h to allow the components to diffuse, react, or reconstruct the crystal phase under solid-state conditions. Then, the furnace is cooled to room temperature.

[0045] 3) The product obtained in step 2) was ground, passed through a 200-mesh sieve, washed with deionized water and anhydrous ethanol, and then vacuum dried at 60 °C to obtain a Cu-Fe composite oxide photocatalyst containing multiple metal elements.

[0046] The prepared catalyst was applied to the photocatalytic water splitting to produce hydrogen: 10 mg of catalyst was weighed and uniformly dispersed in the reaction solution containing the sacrificial agent. The solution was placed in a photocatalytic reactor and a 300 W xenon lamp with an AM 1.5G filter was used as the light source to carry out the photocatalytic water splitting to produce hydrogen at room temperature and pressure.

[0047] Example 2 This embodiment discloses a method for preparing a Cu-Fe-Mo composite oxide photocatalyst containing multiple metal elements, including the following steps: 1) Using copper oxide (CuO), ferric oxide (Fe2O3), and molybdenum oxide (MoO3) as solid precursors, the raw material powders were weighed according to the molar ratio of Cu:Fe:Mo = 1:1:1, and ground and mixed in an agate mortar for 30 minutes to obtain a uniformly mixed precursor powder.

[0048] 2) The precursor powder is transferred to an alumina crucible and placed in a tube furnace. Under a nitrogen atmosphere, the temperature is increased to 700 °C at a heating rate of 5 °C / min and held for 6 h to allow the components to diffuse, react, or reconstruct the crystal phase under solid-state conditions, forming Cu-Fe-Mo composite oxide. After the treatment, the furnace is cooled to room temperature.

[0049] 3) The product obtained in step 2) was ground, passed through a 200-mesh sieve, washed with deionized water and anhydrous ethanol, and then vacuum dried at 60 °C to obtain a Cu-Fe-Mo composite oxide photocatalyst containing multiple metal elements.

[0050] The prepared catalyst was applied to the photocatalytic reduction of nitrogen to synthesize ammonia: 10 mg of catalyst was weighed and dispersed in 80 mL of deionized water or ethanol aqueous solution, placed in a photocatalytic reactor, and high-purity N2 was bubbled in for 30 min to remove air from the system and saturate it with N2; a 300 W xenon lamp was used as the light source, and the photocatalytic reduction of nitrogen was carried out at room temperature and pressure. The NH3 generated in the reaction solution was quantitatively analyzed by Nessler's reagent spectrophotometry or ion chromatography.

[0051] Example 3 This embodiment discloses a method for preparing a Bi-Mo-W composite oxide photocatalyst containing multiple metal elements, including the following steps: 1) Using bismuth trioxide (Bi2O3), tungsten trioxide (WO3), and molybdenum trioxide (MoO3) as solid precursors, the raw material powders were weighed according to the molar ratio of Bi:W:Mo = 2:0.9:0.1, placed in a planetary ball mill jar, and zirconia grinding balls were added. The ball-to-material ratio was 10:1. The mixture was ball-milled at 400 r / min for 8 h to obtain a uniformly mixed precursor powder.

[0052] 2) Transfer the precursor powder obtained in step 1) into a corundum crucible, place it in a muffle furnace, and heat it to 700 °C at a heating rate of 5 °C / min under an air atmosphere. Hold it at this temperature for 5 h to allow the components to diffuse, react, or undergo crystal phase reconstruction under solid-state conditions, forming Mo-doped Bi2WO6 composite oxide. After the treatment is completed, cool it to room temperature with the furnace.

[0053] 3) The product obtained in step 2) was ground, passed through a 200-mesh sieve, washed with deionized water and anhydrous ethanol, and then vacuum dried at 60°C to obtain a Bi-Mo-W composite oxide photocatalyst containing multiple metal elements.

[0054] The prepared catalyst was applied to the photocatalytic synthesis of urea: 10 mg of catalyst was weighed and dispersed in the reaction solution, placed in a closed photocatalytic reactor, and high-purity N2 and CO2 gases were introduced sequentially in a volume ratio of 1:1 to saturate the reaction solution; a 300 W xenon lamp was used as the light source, and the photocatalytic N2 and CO2 co-reduction CN coupling reaction was carried out at room temperature and pressure. The urea generated in the reaction solution was quantitatively analyzed by high performance liquid chromatography.

[0055] Example 4 This embodiment discloses a method for preparing a Ni-Ce composite oxide photocatalyst containing multiple metal elements, including the following steps: 1) Using nickel oxide (NiO) and cerium dioxide (CeO2) as solid precursors, the raw material powder was weighed according to the molar ratio of Ni:Ce = 1:4, placed in a planetary ball mill jar, and zirconium oxide grinding balls were added. The ball-to-material ratio was 10:1. The mixture was ball-milled at a speed of 400 r / min for 6 h to obtain a uniformly mixed precursor powder.

[0056] 2) The precursor powder is transferred to an alumina crucible and placed in a muffle furnace. The temperature is increased to 700 °C at a heating rate of 5 °C / min under an air atmosphere and held for 5 h to allow NiO and CeO2 to diffuse, react or reconstruct the interface under solid-state conditions to form a Ni-CeO2 composite catalyst. After the treatment is completed, the furnace is cooled to room temperature.

[0057] 3) The product obtained in step 2) is transferred into a reduction furnace and heated to 500 °C at a heating rate of 5 °C / min under a mixed atmosphere of H2 / Ar, wherein the H2 content is 5 vol%, and held for 3 h for reduction. After cooling, the product is ground and passed through a 200-mesh sieve to obtain a Ni-Ce composite oxide photocatalyst containing multiple metal elements.

[0058] The prepared catalyst was applied to the photocatalytic ammonia decomposition to produce hydrogen: 10 mg of catalyst was uniformly spread in a gas-solid phase photocatalytic reactor, NH3 / Ar mixed gas was introduced as the reaction gas, a 300 W xenon lamp was used as the light source, and the photocatalytic ammonia decomposition reaction was carried out under room temperature to medium temperature conditions. The H2 and N2 generated by the reaction were quantitatively analyzed by online gas chromatography.

[0059] Example 5 This embodiment uses an all-solid-state reaction preparation method to prepare a series of photocatalyst samples containing multiple metal elements, denoted as NiTiCaO. The crystal structure and light absorption characteristics of the obtained catalysts are characterized by X-ray diffraction and ultraviolet-visible-near-infrared diffuse reflectance absorption spectroscopy, including the following steps: 1) Using two or more metal-containing solid substances as precursors, weigh the raw material powders according to a predetermined molar ratio, and mechanically mix them to obtain a uniformly dispersed mixed precursor; by adjusting the type and ratio of the precursors, mixed precursors of NiTiCaO samples are prepared respectively.

[0060] 2) The mixed precursors were placed in a reaction vessel for solid-phase treatment, with the treatment temperature controlled within the range of 20–2000 °C. After the treatment was completed, the mixture was cooled to room temperature.

[0061] 3) The obtained product was ground, sieved, washed and dried to obtain a NiTiCaO photocatalyst sample.

[0062] Depend on Figure 1 The X-ray diffraction pattern shows that the NiTiCaO multi-component metal photocatalyst prepared in Example 5 exhibits a series of sharp diffraction peaks at approximately 18°, 27°, 33°, 35°, 44°, 47°, 54°, and 64° within the range of 2θ = 5°–85°. The obtained sample shows high peak intensity, sharp peak shape, and narrow half-maximum width, indicating that after treatment by the all-solid-state reaction preparation method, sufficient diffusion, reaction, and structural reconstruction have occurred between the precursors under solid-state conditions, forming a multi-metal composite phase with good crystallinity and a well-defined crystal phase structure. These results demonstrate that the all-solid-state reaction preparation method used in this invention can effectively promote the formation of photocatalysts containing multiple metal elements with stable crystal phase structures from different metal solid precursors under solid-state conditions.

[0063] Depend on Figure 2 The UV-Vis-NIR diffuse reflectance absorption spectrum shows that the NiTiCaO multi-component metal photocatalyst prepared in Example 5 exhibits continuous and high-intensity light absorption in the 200–2500 nm range, covering the UV, visible, and near-infrared bands. Specifically, the sample shows strong absorption in the 200–1000 nm UV-Vis region, with absorbance maintained between approximately 1.2–2.0, and shows absorption characteristics related to electronic transitions of various metal components near approximately 280, 460, and 730 nm, indicating that the prepared catalyst contains multiple photoresponsive active centers. In the 1100–1800 nm near-infrared region, the sample again exhibits a strong and broad absorption band, with absorbance reaching a maximum of approximately 1.95, showing that the catalyst has significant near-infrared light response capability. The above absorption characteristics indicate that by introducing multiple metal elements and preparing the photocatalyst through an all-solid-state reaction, the photoresponse range of the obtained photocatalyst extends from the UV to the near-infrared region, possessing strong potential for full-spectrum light energy utilization.

[0064] It should be noted that the metal-containing solid material includes one or more of the following: metal salts, metal oxides, elemental metals, metal hydroxides, metal carbonates, metal nitrates, metal chlorides, metal sulfates, organometallic salts, metal sulfides, metal nitrides, metal phosphides, and metal carbides; the precursor also contains non-metallic components, which are one or more of the following: sulfur source, nitrogen source, phosphorus source, carbon source, boron source, selenium source, tellurium source, or halogen source; the mechanical mixing method is one or a combination of two or more of the following: grinding, ball milling, stirring mixing, three-dimensional mixing, vibration mixing, rotary mixing, sand milling, and ultrasonic mixing; the solid-phase treatment temperature is 20–2000 ℃, and the treatment time is 0.1–100 minutes. h. By adjusting the processing temperature, processing time, heating rate, cooling rate, and processing atmosphere, the elemental distribution, crystal phase composition, particle morphology, defect structure, and catalytic performance of the obtained photocatalyst are controlled. The solid-phase treatment method is one or a combination of two or more of the following: muffle furnace treatment, tube furnace treatment, box furnace treatment, pit furnace treatment, rotary furnace treatment, fluidized bed treatment, hot pressing sintering, spark plasma sintering, microwave treatment, induction heating treatment, laser treatment, infrared treatment, and electric arc melting. The atmosphere of the solid-phase treatment is one or a combination of two or more of the following: air, oxygen, nitrogen, argon, helium, hydrogen, ammonia, carbon monoxide, carbon dioxide, methane, water vapor, or vacuum. Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0065] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0066] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A photocatalyst containing multiple metal elements, characterized in that, It contains two or more metallic elements, which exist in the form of elemental metals, alloys, intermetallic compounds, metal oxides, complex metal oxides, metal sulfides, metal nitrides, metal phosphides, metal carbides, or complexes thereof.

2. The photocatalyst containing multiple metal elements according to claim 1, characterized in that, The metal element is a transition metal element, a main group metal element, or a rare earth metal element.

3. A method for preparing a photocatalyst containing multiple metal elements as described in claim 1 or 2, characterized in that, Includes the following steps: 1) Using two or more metal-containing solid substances as precursors, mechanically mix them in a predetermined ratio to obtain precursor powder; 2) The precursor powder is placed in a reaction vessel for solid-state treatment, so that different components undergo diffusion, reaction, crystal phase transformation or structural reconstruction under solid-state conditions; 3) The product obtained in step 2) is post-processed to obtain a photocatalyst containing multiple metal elements.

4. The method for preparing a photocatalyst containing multiple metal elements according to claim 3, characterized in that, Solid substances containing metals include one or more of the following: metal salts, metal oxides, elemental metals, metal hydroxides, metal carbonates, metal nitrates, metal chlorides, metal sulfates, organometallic salts, metal sulfides, metal nitrides, metal phosphides, and metal carbides.

5. The method for preparing a photocatalyst containing multiple metal elements according to claim 3, characterized in that, The precursor further comprises a non-metallic component, which is one or more of a sulfur source, nitrogen source, phosphorus source, carbon source, boron source, selenium source, tellurium source or halogen source.

6. The method for preparing a photocatalyst containing multiple metal elements according to claim 3, characterized in that, The mechanical mixing method is one or a combination of two or more of the following: grinding, ball milling, stirring, three-dimensional mixing, vibration mixing, rotational mixing, sand milling, and ultrasonic mixing.

7. The method for preparing a photocatalyst containing multiple metal elements according to claim 3, characterized in that, The solid-phase treatment temperature is 20–2000 °C, and the treatment time is 0.1–100 h. By adjusting the treatment temperature, treatment time, heating rate, cooling rate, and treatment atmosphere, the elemental distribution, crystal phase composition, particle morphology, defect structure, and catalytic performance of the obtained photocatalyst can be controlled.

8. The method for preparing a photocatalyst containing multiple metal elements according to claim 7, characterized in that, The solid-state treatment method is one or a combination of two or more of the following: muffle furnace treatment, tube furnace treatment, box furnace treatment, pit furnace treatment, rotary furnace treatment, fluidized bed treatment, hot pressing sintering, spark plasma sintering, microwave treatment, induction heating treatment, laser treatment, infrared treatment, and electric arc melting.

9. The method for preparing a photocatalyst containing multiple metal elements according to claim 7, characterized in that, The atmosphere for the solid-phase treatment is one or a combination of two or more of the following: air, oxygen, nitrogen, argon, helium, hydrogen, ammonia, carbon monoxide, carbon dioxide, methane, water vapor, or vacuum.

10. The application of a photocatalyst containing multiple metal elements as described in claim 1 or 2 in photocatalytic reactions.

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