Composite photoelectric catalyst as well as preparation method and application thereof
By forming a composite structure of samarium oxide and copper oxide on the conductive glass, the problem of low photocatalyst activity is solved, the photocatalytic efficiency is improved, and energy consumption is reduced, making it suitable for large-scale production.
Patent Information
- Application Number
- CN202510599276.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-10
- Publication Date
- 2025-08-12
AI Technical Summary
The catalytic activity of existing photoelectric catalysts is low, which hinders the improvement of photoelectric catalytic solar energy conversion efficiency and limits its large-scale application.
Samarium salt and copper salt are used as raw materials to generate a precursor solution through the excitation reaction of acetylacetone, spin-coated onto the conductive glass and calcined at low temperature to form a composite structure of samarium oxide and copper oxide, which promotes charge separation and light absorption, and improves photoelectrocatalytic efficiency.
It achieves the improvement of the photoresponse current, broadens the light absorption range, enhances the stability of copper oxide, simplifies the preparation process and reduces energy consumption, and is suitable for large-scale production.
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Figure CN120465047A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of photoelectrocatalysis technology, and in particular to a composite photoelectrocatalyst and a preparation method and application thereof. Background Art
[0002] Various clean energy sources, led by hydrogen, are emerging as highly efficient, energy-efficient, and promising. Ever since titanium dioxide was first used as a photoelectrocatalyst, photoelectrochemical (PEC) systems have been considered a promising energy conversion method. Despite years of development, a wide variety of photoelectrocatalysts and cell design strategies have emerged. However, overall, the efficiency of photoelectrocatalytic solar energy conversion remains low, hindering large-scale application. Therefore, improving the catalytic activity of photoelectrocatalysts has become a highly sought-after research topic in this field.
[0003] To date, a wide variety of materials have been designed as photoelectrocatalytic materials, including traditional TiO2, WO3, and BiVO4, as well as novel g-C3N4, MOFs, and COFs. Each material possesses unique physical and chemical properties, with its own strengths and weaknesses. Their rational combination is crucial for improving the overall performance of photoelectrocatalytic electrodes. Based on this, the present invention provides a novel composite photoelectrocatalyst, aiming to enhance the overall performance of photoelectrocatalytic electrodes and accelerate their application in the field of photoelectrocatalysis. Summary of the Invention
[0004] The first object of the present invention is to provide a method for preparing a composite photoelectrocatalyst, which is simple to operate, low-temperature and energy-saving, and can be produced on a large scale.
[0005] The second object of the present invention is to provide a composite photoelectrocatalyst having excellent photoelectrocatalytic effect.
[0006] The third purpose of the present invention is to provide an application of a composite photoelectrocatalyst with broad application prospects.
[0007] In order to achieve the above object, the technical solution adopted by the present invention is:
[0008] A method for preparing a composite photoelectrocatalyst comprises the following steps:
[0009] (1) adding samarium salt and copper salt to ethylene glycol methyl ether, then adding acetylacetone and stirring, then adding ammonia water and mixing evenly, and aging to obtain a precursor solution;
[0010] (2) coating the precursor solution of step (1) onto pretreated conductive glass, and calcining to obtain the composite photoelectrocatalyst.
[0011] The present invention utilizes a method of combining organic and inorganic raw materials to first configure a precursor solution in preparation for the next step. This configuration method enables the acetylacetone organic solution to be excited during the reaction process and provide a large amount of heat, so that the reaction can occur. No other energy needs to be provided artificially, thus saving the energy demand of the reaction process. The precursor solution is then spin-coated onto conductive glass, and a composite structure of samarium oxide and copper oxide is grown on the surface of the conductive glass through low-temperature calcination. The composite structure formed by samarium oxide Sm2O3 and copper oxide CuO can promote charge separation, thereby increasing the photoresponse current. Specifically, the copper oxide in the composite structure can effectively promote light absorption, charge separation and transfer, broaden the light absorption range, and improve the photoelectrocatalytic efficiency. Samarium oxide can increase the stability of copper oxide, slow down the deactivation process of the electrode, and enhance the photoelectrocatalytic performance.
[0012] Furthermore, the pretreated conductive glass is specifically prepared by immersing the conductive glass in a mixed solution, ultrasonically treating it for 10-20 minutes, and then drying it; the mixed solution is composed of ammonia water, hydrogen peroxide solution, and water in a mass ratio of 1:1:(5-6); the ammonia content in the ammonia water is 25-28%, and the concentration of the hydrogen peroxide solution is 20-30%.
[0013] The present invention can remove pollutants attached to the surface of the conductive glass by pre-treating the conductive glass, ensure the surface is smooth and clean, improve the hydrophilicity of the conductive side, and thus facilitate the uniform growth of two oxide complexes on the surface.
[0014] Furthermore, the usage ratio of the samarium salt, copper salt, acetylacetone and ammonia water in step (1) is 1 mmol: (0.5-2) mmol: (100-300) μL: (110-120) μL.
[0015] Furthermore, the usage ratio of the samarium salt, copper salt, acetylacetone and ammonia water is 1 mmol: 1 mmol: 200 μL: 114 μL.
[0016] Furthermore, the samarium salt is samarium nitrate, and the copper salt is copper nitrate.
[0017] Furthermore, the aging time in step (1) is 12-14 hours.
[0018] Furthermore, in step (2), the thickness of the precursor solution coated on the pretreated conductive glass is 200-300 nm; the calcination temperature is 450-550° C., and the calcination time is 2.5-3.5 h.
[0019] Furthermore, the calcination temperature is 500° C. and the calcination time is 3 hours.
[0020] The invention grows a composite structure of samarium oxide and copper oxide on the surface of conductive glass by a low-temperature combustion method.
[0021] Furthermore, the coating is spin coating; the conductive glass is made of FTO or ITO.
[0022] Furthermore, the spin coating parameters are as follows: rotation speed is 2900-3100 rpm, time is 15-25s, acceleration is 450-550 rpm 2 .
[0023] A composite photoelectric catalyst is prepared by using the above-mentioned preparation method of the composite photoelectric catalyst.
[0024] Application of the above composite photoelectrocatalyst in photoelectrocatalytic water splitting.
[0025] The beneficial technical effects of the present invention are:
[0026] 1. The present invention provides a method for preparing a composite photoelectrocatalyst. Specifically, a precursor solution containing a samarium salt and a copper salt is first prepared. The precursor solution is then spin-coated onto a conductive glass surface. After low-temperature calcination, a composite structure of samarium oxide and copper oxide is grown on the surface of the conductive glass. The composite structure promotes charge separation, thereby increasing the photoresponse current. Specifically, the copper oxide in the composite structure effectively promotes light absorption, charge separation, and transfer, broadens the light absorption range, and improves the photoelectrocatalytic efficiency. The samarium oxide increases the stability of the copper oxide, slows the deactivation process of the electrode, and enhances the photoelectrocatalytic performance.
[0027] 2. The preparation method of the composite photoelectrocatalyst of the present invention is simple to operate, low-temperature and energy-saving, and can be produced on a large scale.
[0028] 3. The composite photoelectrocatalyst of the present invention has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 This is a sample diagram of the precursor solution of Example 1;
[0030] Figure 2 : is an SEM image of the composite photoelectrocatalyst obtained in Example 1; wherein A is a microscopic morphology of the composite photoelectrocatalyst, B is a superimposed distribution diagram of the three elements contained in the composite photoelectrocatalyst, C is a distribution diagram of the oxygen element in the composite photoelectrocatalyst, D is a distribution diagram of the copper element in the composite photoelectrocatalyst, and E is a distribution diagram of the samarium element in the composite photoelectrocatalyst;
[0031] Figure 3 1-4 and 1-2 are XRD patterns of the photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2;
[0032] Figure 41-2 are the linear sweep voltammograms of the photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2. DETAILED DESCRIPTION
[0033] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, without departing from the inventive concept, several simple deductions or replacements can also be made, all of which should be considered to fall within the scope of protection of the present invention. The specific conditions not specified in the examples are carried out under conventional conditions. The reagents or instruments used, unless otherwise specified, are conventional products obtained through commercial channels.
[0034] The size of the FTO conductive glass of the present invention is 2×2 cm 2 , thickness is 2.0-2.2mm, transmittance is more than 80%, and square resistance is 6-7Ω.
[0035] The density of the ethylene glycol methyl ether of the invention is 1.18 g / mL, the density of acetylacetone at 20° C. is 0.98 g / mL, and the concentration of the hydrogen peroxide solution is 20-30%.
[0036] Example 1
[0037] Example 1 provides a method for preparing a composite photoelectrocatalyst. The specific preparation process is as follows:
[0038] (1) 1 mmol of Sm(NO3)3·6H2O and 1 mmol of Cu(NO3)3·3H2O were added to 5 mL of ethylene glycol methyl ether, and then 200 μL of acetylacetone was added and stirred until completely dissolved. Then, 114 μL of ammonia water with an ammonia content of 26 wt% was added and mixed evenly. After aging for 12 h, a precursor solution was obtained. The precursor solution sample is shown in FIG. Figure 1 ;
[0039] (2) The FTO conductive glass was immersed in a mixed solution consisting of ammonia water, hydrogen peroxide solution, and water in a mass ratio of 1:1:5 and ultrasonically treated for 15 minutes. The FTO conductive glass was then dried with high-purity nitrogen (N2, 99.999%) to obtain pretreated conductive glass. The parameters of the spin coater were set as follows: speed of 3000 rpm, time of 20 s, acceleration of 500 rpm. 2 , the precursor solution of step (1) is spin-coated onto the pretreated FTO conductive glass by a spin coater, and the thickness of the precursor solution spin-coated onto the pretreated conductive glass is 220 nm; after the spin coating is completed, the FTO conductive glass is placed on an alumina crucible cover, calcined in an air atmosphere at 500°C in a tube furnace for 2 hours, and naturally cooled to obtain the composite photoelectrocatalyst.
[0040] Example 1 also provides a composite photoelectrocatalyst, which is prepared using the above-mentioned preparation method of the composite photoelectrocatalyst.
[0041] Example 2
[0042] Example 2 provides a method for preparing a composite photoelectrocatalyst. The specific preparation process is as follows:
[0043] (1) 1 mmol of Sm(NO3)3·6H2O and 0.5 mmol of Cu(NO3)3·3H2O were added to 5 mL of ethylene glycol methyl ether, followed by the addition of 100 μL of acetylacetone, which was stirred until completely dissolved. 110 μL of aqueous ammonia with an ammonia content of 25 wt% was then added and mixed uniformly. The precursor solution was obtained after aging for 13 h.
[0044] (2) The FTO conductive glass was immersed in a mixed solution of ammonia water, hydrogen peroxide solution, and water in a mass ratio of 1:1:6 and ultrasonically treated for 10 minutes. The FTO conductive glass was then dried with high-purity nitrogen (N2, 99.999%) to obtain pretreated conductive glass. The parameters of the spin coater were set as follows: speed of 2900 rpm, time of 15 s, acceleration of 450 rpm. 2 , the precursor solution of step (1) is spin-coated onto the pretreated FTO conductive glass by a spin coater, and the thickness of the precursor solution spin-coated onto the pretreated conductive glass is 200 nm; after the spin coating is completed, the FTO conductive glass is placed on an alumina crucible cover, calcined in an air atmosphere at 450°C in a tube furnace for 2.5 hours, and naturally cooled to obtain the composite photoelectrocatalyst.
[0045] Example 2 also provides a composite photoelectrocatalyst, which is prepared using the above-mentioned preparation method of the composite photoelectrocatalyst.
[0046] Example 3
[0047] Example 3 provides a method for preparing a composite photoelectrocatalyst. The specific preparation process is as follows:
[0048] (1) 1 mmol of Sm(NO3)3·6H2O and 2 mmol of Cu(NO3)3·3H2O were added to 5 mL of ethylene glycol methyl ether, and then 300 μL of acetylacetone was added and stirred until completely dissolved. Then, 120 μL of ammonia water with an ammonia content of 28 wt% was added and mixed uniformly. After aging for 14 h, a precursor solution was obtained;
[0049] (2) The FTO conductive glass was immersed in a mixed solution of ammonia water, hydrogen peroxide solution, and water in a mass ratio of 1:1:5 and ultrasonically treated for 20 minutes. The ITO conductive glass was then dried with high-purity nitrogen (N2, 99.999%) to obtain pretreated conductive glass. The parameters of the spin coater were set as follows: speed of 3100 rpm, time of 25 s, acceleration of 550 rpm. 2 , the precursor solution of step (1) is spin-coated onto the pretreated FTO conductive glass by a spin coater, and the thickness of the precursor solution spin-coated onto the pretreated conductive glass is 300 nm; after the spin coating is completed, the FTO conductive glass is placed on an alumina crucible cover, calcined in an air atmosphere at 550°C in a tube furnace for 3.5 hours, and naturally cooled to obtain the composite photoelectrocatalyst.
[0050] Example 3 also provides a composite photoelectrocatalyst, which is prepared using the above-mentioned preparation method of the composite photoelectrocatalyst.
[0051] Example 4
[0052] The difference between Example 4 and Example 1 is that the molar ratio of Sm(NO3)3·6H2O and Cu(NO3)3·3H2O is 1.5:1, and the rest is the same as Example 1.
[0053] Comparative Example 1
[0054] The difference between Comparative Example 1 and Example 1 is that Cu(NO3)3·3H2O is omitted, and the rest is the same as Example 1.
[0055] Comparative Example 2
[0056] The difference between Comparative Example 2 and Example 1 is that Sm(NO3)3·6H2O is omitted, and the rest is the same as Example 1.
[0057] Test Example 1
[0058] The morphology of the composite photoelectrocatalyst obtained in Example 1 was observed using a scanning electron microscope. Figure 2 .
[0059] Figure 2 This is the SEM image of the composite photoelectrocatalyst obtained in Example 1, where A is the microscopic morphology of the catalyst, B is the superimposed distribution diagram of the three elements contained in the catalyst, C is the distribution diagram of the oxygen element in the catalyst, D is the distribution diagram of the copper element in the catalyst, and E is the distribution diagram of the samarium element in the catalyst. Figure 2 It can be seen that the composite photoelectrocatalyst obtained in Example 1 does not present a separate structure, but is aggregated into a solidified state with a porous network structure in the middle, and the pores are interconnected by fibrous tissue to form a three-dimensional through-hole system.
[0060] Test Example 2
[0061] The photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2 were tested by X-ray diffraction. Figure 3 .
[0062] Figure 3 The XRD patterns of the photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2 are shown in FIG. Figure 3 It can be seen that Comparative Examples 1-2 are two pure metal oxides, namely samarium oxide and copper oxide, which correspond to the standard card spectrum library; Example 1 was synthesized and compared with the copper oxide and samarium oxide cards in the standard card spectrum library, and it was determined that it was a composite containing two oxides. Example 2 was synthesized by comparison and found to be a samarium cuprate material with a spinel structure. Examples 3-4 were compared with the standard card spectrum library and found to be a composite of two metal oxides.
[0063] Test Example 3
[0064] The performance of the photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2 in photoelectrocatalytic water splitting was tested. The specific testing process is as follows:
[0065] (1) All photoelectrochemical measurements were performed using an electrochemical workstation in a three-electrode cell at room temperature, with the anode (catalysts obtained in Examples 1-4 and Comparative Examples 1-2) as the working electrode, Pt foil as the counter electrode, Ag / AgCl as the reference electrode, and the electrolyte being a KHCO solution with a pH of 8.3 and a concentration of 2 mol / L.
[0066] (2) The photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2 were respectively inserted into the electrolyte, with a test area of 1×2 cm 2 , the photocurrent was measured using linear sweep voltammetry (LSV), and the scan rate was kept at 0.01 V / s;
[0067] (3) According to the Nernst equation (E RHE =E Ag / AgCl +0.0591pH+E 0 Ag / Cl ), the measured potential of the Ag / AgCl electrode (saturated KCl solution) is converted into the potential of the reversible hydrogen electrode (V RHE ) potential, see Figure 4 .
[0068] Figure 4 The linear sweep voltammograms of the photoelectrocatalysts obtained in Examples 1-4 and Comparative Examples 1-2 are shown. Figure 4It can be seen that when the Sm / Cu ratio is less than 1, the crystal structure of the synthesized complex is spinel; when the Sm / Cu ratio is greater than 1, the crystal structure of the synthesized catalyst becomes a composite of two oxides (copper oxide and samarium oxide); when the Sm / Cu ratio is 1, its current density is the highest, and it can achieve the best photoelectrocatalytic performance, showing excellent PEC performance. According to the ratio of 1, this synthesis method can synthesize oxide complex catalysts with good morphology and performance.
[0069] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.
Claims
1. A method for preparing a composite photoelectrocatalyst, characterized in that: The steps include: (1) adding samarium salt and copper salt to ethylene glycol methyl ether, then adding acetylacetone and stirring, then adding ammonia water and mixing evenly, and aging to obtain a precursor solution; (2) coating the precursor solution of step (1) onto pretreated conductive glass, and calcining to obtain the composite photoelectrocatalyst.
2. The method for preparing the composite photoelectrocatalyst according to claim 1, characterized in that: The usage ratio of the samarium salt, copper salt, acetylacetone and ammonia water in step (1) is 1 mmol: (0.5-2) mmol: (100-300) μL: (110-120) μL; the ammonia content in the ammonia water is 25-28%.
3. The method for preparing the composite photoelectrocatalyst according to claim 2, characterized in that: The usage ratio of the samarium salt, copper salt, acetylacetone and ammonia water is 1 mmol: 1 mmol: 200 μL: 114 μL.
4. The method for preparing the composite photoelectrocatalyst according to claim 2 or 3, characterized in that: The samarium salt is samarium nitrate, and the copper salt is copper nitrate.
5. The method for preparing the composite photoelectrocatalyst according to claim 1, characterized in that: The aging time in step (1) is 12-14 hours.
6. The method for preparing the composite photoelectrocatalyst according to claim 1, characterized in that: In step (2), the thickness of the precursor solution coated on the pretreated conductive glass is 200-300 nm; the calcination temperature is 450-550° C., and the calcination time is 2.5-3.5 h.
7. The method for preparing the composite photoelectrocatalyst according to claim 6, characterized in that: The coating is spin coating; the conductive glass is made of FTO or ITO.
8. The method for preparing the composite photoelectrocatalyst according to claim 7, characterized in that: The spin coating parameters are as follows: rotation speed 2900-3100 rpm, time 15-25 s, acceleration 450-550 rpm 2 .
9. A composite photoelectrocatalyst, characterized in that The composite photoelectrocatalyst is prepared by the preparation method of any one of claims 1 to 8.
10. Use of the composite photoelectrocatalyst according to claim 9 in photoelectrocatalytic water splitting.