Application of tungsten oxide-based composite photoelectrocatalysis material growing on FTO (Fluorine-doped Tin Oxide) in photoelectrocatalysis

Abstract

The invention discloses application of a tungsten oxide-based composite photoelectrocatalysis material growing on FTO (Fluorine-doped Tin Oxide) in photoelectrocatalysis, and the composite photoelectrocatalysis material is applied to photoelectrocatalytic decomposition of water to produce hydrogen, photoelectrocatalytic degradation of organic pollutants, photoelectrocatalytic reduction of carbon dioxide, photoelectrocatalytic degradation of organic pollutants, photoelectrocatalytic degradation of organic pollutants and photoelectrocatalytic reduction of organic pollutants. The specific application method comprises the steps that the composite photoelectric catalytic material is applied to a photoelectric catalytic reaction, then the used composite photoelectric catalytic material is subjected to regeneration treatment, then the regenerated composite photoelectric catalytic material is applied to the photoelectric catalytic reaction again, and cyclic utilization of the composite photoelectric catalytic material in the photoelectric catalytic reaction is achieved. The tungsten oxide-based composite photoelectric catalytic material prepared by the invention is compounded with a second-phase semiconductor to form an II-type heterogeneous composite material with a three-dimensional hierarchical structure, so that the separation efficiency of electrons and holes is effectively improved, the compounding rate of photo-induced electrons and holes is reduced in a photocatalytic reaction, the preparation process is simple, the cost is low, and the method is suitable for industrial production. The method is suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectrocatalysis technology, and in particular to the application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis. Background Art

[0002] As energy crisis and environmental problems become increasingly serious, using sunlight for photocatalytic reactions has become one of the effective ways to solve these problems. As a common semiconductor photocatalyst, tungsten oxide (WO3) has a suitable band gap (2.5-2.8eV) and can capture nearly 12% of the solar spectrum. It is widely used in adsorption, catalysis, energy storage and sensitive devices.

[0003] However, tungsten oxide-based materials usually have poor conductivity and a fast recombination rate of photogenerated electrons and holes, which limits the improvement of their photoelectrocatalytic performance.

[0004] To this end, we propose the application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide an application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis. The composite photoelectrocatalytic material is used for photoelectrocatalytic decomposition of water to produce hydrogen, photoelectrocatalytic degradation of organic pollutants, and photoelectrocatalytic reduction of carbon dioxide. The specific application method is: applying the composite photoelectrocatalytic material to a photoelectrocatalytic reaction, then regenerating the used composite photoelectrocatalytic material, and then reapplying the regenerated composite photoelectrocatalytic material to the photoelectrocatalytic reaction, thereby realizing the recycling of the composite photoelectrocatalytic material in the photoelectrocatalytic reaction. The specific application steps are as follows:

[0008] S1. The composite photoelectrocatalytic material is sequentially fixed on the inner wall of the reactor containing the solution to be catalyzed, and is arranged around a circle so that the composite photoelectrocatalytic material is inserted into the reaction solution, and at the same time, some of the bulk of the composite photoelectrocatalytic material is scraped off and dispersed in the reaction solution, and a visible light source is set on the reactor to fully irradiate the composite photoelectrocatalytic material, and a photocatalytic reaction is carried out for 1 hour under visible light irradiation;

[0009] S2. After the reaction is completed, the composite photoelectrocatalytic material is separated from the reaction medium by filtering, centrifuging or the like, and the recovered composite photoelectrocatalytic material is cleaned and dried;

[0010] S3. Reapply the composite photoelectrocatalytic material regenerated in step S2 to the next photocatalytic reaction experiment.

[0011] In a further embodiment, the above-mentioned photocatalytic process is carried out at normal temperature and pressure.

[0012] In a further embodiment, the reactor in S1 is provided with a stirring device.

[0013] In a further embodiment, the visible light source in step S1 is a 300W xenon lamp that obtains visible light of ≧420nm through an ultraviolet filter.

[0014] In a further embodiment, a sacrificial agent such as methanol or ethanol may be added during the reaction in step S1.

[0015] In a further embodiment, the preparation method of the composite photoelectrocatalytic material is: first, using FTO conductive glass sheet as a substrate, preparing tungsten oxide by a solvothermal method, and then selecting a second phase semiconductor that matches the band gap of tungsten oxide, and using a solvothermal method to epitaxially grow on the surface of tungsten oxide to form a three-dimensional hierarchical structure of type II heterogeneous composite material.

[0016] In a further embodiment, the second phase semiconductor is any one of TiO2, ZnO, Sn3O4, SnO2, BiVO4, Bi2WO6, and Bi2MoO6.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The tungsten oxide-based composite photoelectrocatalytic material prepared by the present invention has good structure and morphology and exhibits excellent photoelectrocatalytic activity.

[0019] The tungsten oxide-based composite photoelectrocatalytic material prepared by the present invention is compounded with a second phase semiconductor to form a type II heterogeneous composite material with a three-dimensional hierarchical structure, which effectively improves the separation efficiency of electrons and holes and reduces the recombination rate of photogenerated electrons and holes.

[0020] The tungsten oxide-based composite photoelectrocatalytic material prepared by the present invention has a simple preparation process, low cost, and a universal synthesis method, and is suitable for large-scale production.

[0021] The tungsten oxide-based composite photoelectrocatalytic material prepared by the present invention has a good application prospect in photoelectrocatalytic water decomposition to produce hydrogen, and provides a new solution to solve the energy crisis and environmental problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a scanning electron microscope photo of WO3 of the present invention;

[0023] Figure 2 This is a scanning electron microscope photograph of the WO3 and ZnO composite photoelectrocatalytic material of the present invention. DETAILED DESCRIPTION

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1: Application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis. The composite photoelectrocatalytic material is applied to photoelectrocatalytic decomposition of water to produce hydrogen. The specific application method is: applying the composite photoelectrocatalytic material to the reaction of photoelectrocatalytic decomposition of water to produce hydrogen, then regenerating the used composite photoelectrocatalytic material, and then reapplying the regenerated composite photoelectrocatalytic material to the reaction of photoelectrocatalytic decomposition of water to produce hydrogen, thereby realizing the recycling of the composite photoelectrocatalytic material in the reaction of photoelectrocatalytic decomposition of water to produce hydrogen. The specific application steps are as follows:

[0028] S1. First, take FTO conductive glass sheet as substrate and use solvent thermal method to prepare tungsten oxide. Then select second phase semiconductor ZnO which matches the band gap of tungsten oxide and use solvent thermal method to epitaxially grow on the surface of tungsten oxide to form type II heterogeneous composite material with three-dimensional hierarchical structure. Fix the substrate where the composite photoelectric catalytic material is located on the inner wall of the reactor filled with aqueous solution in turn and surround it for a circle so that the composite photoelectric catalytic material is inserted into the aqueous solution. At the same time, scrape off some bulk materials of the composite photoelectric catalytic material and disperse it in the aqueous solution. The reactor is equipped with a stirring device. The stirring device stirs the aqueous solution and bulk materials in the dark for 20-30 minutes to make the composite photoelectric catalytic material The catalytic material is evenly distributed in the aqueous solution, and a visible light source is set on the reactor for irradiation. The visible light source is a 300W xenon lamp that obtains visible light of ≧420nm through an ultraviolet filter to fully irradiate the composite photoelectrocatalytic material. The entire reaction process is carried out at room temperature and pressure. Methanol, ethanol and other sacrificial agents can also be added to consume photogenerated holes or electrons to improve hydrogen production efficiency. The photocatalytic reaction is carried out for 1h. During the reaction, the photocatalytic material absorbs light energy to generate electron and hole pairs, and the electrons reduce water to hydrogen, and the holes oxidize water to oxygen. The generated hydrogen is collected by an appropriate gas collection device (such as an air bag, a gas chromatograph, etc.);

[0029] S2. After the reaction is completed, the composite photoelectrocatalytic material is separated from the aqueous solution by filtering, centrifuging, etc., and the recovered composite photoelectrocatalytic material is washed and dried;

[0030] S3. Reapplying the composite photoelectrocatalytic material regenerated in step S2 to the next photoelectrocatalytic water decomposition hydrogen production reaction experiment.

[0031] Example 2: Application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis. The composite photoelectrocatalytic material is applied to photoelectrocatalytic degradation of organic pollutants. The specific application method is: applying the composite photoelectrocatalytic material to the reaction of photoelectrocatalytic degradation of organic pollutants, then regenerating the used composite photoelectrocatalytic material, and then reapplying the regenerated composite photoelectrocatalytic material to the reaction of photoelectrocatalytic degradation of organic pollutants, thereby realizing the recycling of the composite photoelectrocatalytic material in the reaction of photoelectrocatalytic degradation of organic pollutants. The specific application steps are as follows:

[0032] S1. First, take FTO conductive glass sheet as substrate and use solvent thermal method to prepare tungsten oxide. Then select the second phase semiconductor ZnO that matches the band gap of tungsten oxide and use solvent thermal method to epitaxially grow on the surface of tungsten oxide to form a type II heterogeneous composite material with a three-dimensional hierarchical structure. The substrate where the composite photoelectric catalytic material is located is fixed on the inner wall of the reactor containing the organic pollutant solution in sequence and surrounds it for a circle so that the composite photoelectric catalytic material is inserted into the organic pollutant solution. At the same time, some of the bulk of the composite photoelectric catalytic material is scraped off and dispersed in the organic pollutant solution. The reactor is equipped with a stirring device, which stirs the organic pollutant solution and the bulk material in the dark for 20-30 minutes. n, so that the composite photoelectrocatalytic material is evenly distributed in the organic pollutant solution, and a visible light source is set on the reactor for irradiation. The visible light source is a 300W xenon lamp that obtains visible light of ≧420nm through an ultraviolet filter to fully irradiate the composite photoelectrocatalytic material. The entire reaction process is carried out at room temperature and pressure, and the photocatalytic reaction is carried out for 1h. During the reaction, the photocatalytic material absorbs light energy to generate electron-hole pairs, and these electrons and holes react with oxygen molecules, water molecules, etc. in the solution to generate free radicals (such as hydroxyl free radicals, superoxide free radicals, etc.), which in turn react with organic pollutants to degrade them into harmless substances (such as carbon dioxide, water, etc.);

[0033] S2. After the reaction is completed, the composite photoelectrocatalytic material is separated from the aqueous solution by filtering, centrifuging, etc., and the recovered composite photoelectrocatalytic material is washed and dried;

[0034] S3, reapplying the composite photoelectrocatalytic material regenerated in step S2 to the next photoelectrocatalytic water decomposition hydrogen production reaction experiment,

[0035] In addition, the degradation products are analyzed using instruments such as gas chromatographs and liquid chromatographs to determine their types and concentrations, and then the degradation efficiency is calculated by comparing the concentrations of organic pollutants before and after degradation.

[0036] Example 3: Application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis. The composite photoelectrocatalytic material is applied to the photoelectrocatalytic reduction of carbon dioxide. The specific application method is: applying the composite photoelectrocatalytic material to the reaction of photoelectrocatalytic reduction of carbon dioxide, then regenerating the used composite photoelectrocatalytic material, and then reapplying the regenerated composite photoelectrocatalytic material to the reaction of photoelectrocatalytic reduction of carbon dioxide, thereby realizing the recycling of the composite photoelectrocatalytic material in the reaction of photoelectrocatalytic reduction of carbon dioxide. The specific application steps are as follows:

[0037] S1. First, take FTO conductive glass sheet as substrate and use solvent thermal method to prepare tungsten oxide. Then select second phase semiconductor ZnO which matches the band gap of tungsten oxide and use solvent thermal method to epitaxially grow on the surface of tungsten oxide to form type II heterogeneous composite material with three-dimensional hierarchical structure. Fix the substrate where the composite photoelectrocatalytic material is located on the inner wall of the reactor containing the reaction medium containing carbon dioxide in sequence and surround it for a circle so that the composite photoelectrocatalytic material is inserted into the reaction medium containing carbon dioxide. At the same time, scrape off part of the bulk of the composite photoelectrocatalytic material and disperse it in the reaction medium containing carbon dioxide. The reactor is provided with a stirring device. The stirring device stirs the reaction medium containing carbon dioxide. The reaction medium containing carbon dioxide and the bulk material are stirred in the dark for 20-30 minutes, so that the composite photoelectrocatalytic material is evenly distributed in the reaction medium containing carbon dioxide, and a visible light source is set on the reactor for irradiation. The visible light source is a 300W xenon lamp that obtains visible light of ≧420nm through an ultraviolet filter to fully irradiate the composite photoelectrocatalytic material. The entire reaction process is carried out at room temperature and pressure, and the photocatalytic reaction is carried out for 1 hour. During the reaction process, the photocatalytic material absorbs light energy to generate electron-hole pairs, and these electrons and holes react with carbon dioxide molecules, water molecules, etc. to generate reduction products (such as carbon monoxide, methane, formic acid, methanol, etc.);

[0038] S2. After the reaction is completed, the composite photoelectrocatalytic material is separated from the aqueous solution by filtering, centrifuging, etc., and the recovered composite photoelectrocatalytic material is washed and dried;

[0039] S3, reapplying the composite photoelectrocatalytic material regenerated in step S2 to the next photoelectrocatalytic water decomposition hydrogen production reaction experiment,

[0040] In addition, the reduction product is separated from the reaction medium by distillation, extraction, chromatography, and the like.

[0041] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0042] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. Application of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO in photoelectrocatalysis, characterized in that: The composite photoelectrocatalytic material is used for photoelectrocatalytic decomposition of water to produce hydrogen, photoelectrocatalytic degradation of organic pollutants, and photoelectrocatalytic reduction of carbon dioxide. The specific application method is: applying the composite photoelectrocatalytic material to the photoelectrocatalytic reaction, then regenerating the used composite photoelectrocatalytic material, and then reapplying the regenerated composite photoelectrocatalytic material to the photoelectrocatalytic reaction, thereby realizing the recycling of the composite photoelectrocatalytic material in the photoelectrocatalytic reaction. The specific application steps are as follows: S1. The composite photoelectrocatalytic material is sequentially fixed on the inner wall of the reactor containing the solution to be catalyzed, and is arranged around a circle so that the composite photoelectrocatalytic material is inserted into the reaction solution, and at the same time, some of the bulk of the composite photoelectrocatalytic material is scraped off and dispersed in the reaction solution, and a visible light source is set on the reactor to fully irradiate the composite photoelectrocatalytic material, and a photocatalytic reaction is carried out for 1 hour under visible light irradiation; S2. After the reaction is completed, the composite photoelectrocatalytic material is separated from the reaction medium by filtering, centrifuging or the like, and the recovered composite photoelectrocatalytic material is cleaned and dried; S3. Reapply the composite photoelectrocatalytic material regenerated in step S2 to the next photocatalytic reaction experiment.

2. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 1 in photoelectrocatalysis, characterized in that: The above-mentioned photocatalytic process is carried out at normal temperature and pressure.

3. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 1 in photoelectrocatalysis, characterized in that: The reactor in S1 is provided with a stirring device.

4. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 1 in photoelectrocatalysis, characterized in that: The visible light source in step S1 is a 300W xenon lamp that passes through an ultraviolet filter to obtain visible light of ≥420nm.

5. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 1 in photoelectrocatalysis, characterized in that: During the reaction in step S1, a sacrificial agent such as methanol or ethanol may be added.

6. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 1 in photoelectrocatalysis, characterized in that: The preparation method of the composite photoelectrocatalytic material is as follows: first, a FTO conductive glass sheet is used as a substrate, tungsten oxide is prepared by a solvothermal method, and then a second phase semiconductor matching the band gap of tungsten oxide is selected, and epitaxial growth is performed on the surface of tungsten oxide by a solvothermal method to form a type II heterogeneous composite material with a three-dimensional hierarchical structure.

7. The use of a tungsten oxide-based composite photoelectrocatalytic material grown on FTO according to claim 6 in photoelectrocatalysis, characterized in that: The second phase semiconductor is any one of TiO2, ZnO, Sn3O4, SnO2, BiVO4, Bi2WO6, and Bi2MoO6.

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