A copper bismuthate-based composite thin film electrode material, a preparation method and application thereof
By constructing a pn heterojunction structure on a copper bismuthate thin film and introducing an electrocatalytically active material layer, the problem of insufficient photoelectrocatalytic performance of copper bismuthate thin films was solved, and efficient degradation of organic pollutants was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EAST CHINA UNIV OF SCI & TECH
- Filing Date
- 2026-03-17
- Publication Date
- 2026-06-05
AI Technical Summary
Copper bismuthate films suffer from high recombination rates of photogenerated carriers and insufficient interfacial charge transport efficiency during photoelectrocatalysis, which hinders the improvement of their photoelectrocatalytic performance.
A pn heterojunction structure was constructed on a copper bismuthate thin film. By sequentially forming a copper bismuthate thin film layer, a cadmium sulfide layer, and an electrocatalytic active material layer on a conductive substrate, a built-in electric field was formed to promote the separation of photogenerated electrons and holes. An electrocatalytic active material layer was introduced at the interface to enhance the charge transport process.
It improves carrier migration efficiency and interfacial charge transport capacity, enhances photoelectrocatalytic performance, and achieves efficient degradation of organic pollutants.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor photocatalytic functional materials technology, specifically relating to a copper bismuthate-based composite thin film electrode material, its preparation method, and its application in photocatalytic degradation of organic pollutants. Background Technology
[0002] With the acceleration of industrialization and urbanization, recalcitrant organic pollutants such as antibiotics, surfactants, dyes, and pesticides are accumulating in aquatic environments, posing a potential threat to ecosystem stability and water safety. Therefore, developing efficient, stable, and sustainable organic pollutant removal technologies has become an important research direction in the field of environmental governance.
[0003] Currently, adsorption and advanced oxidation methods are commonly used technologies for treating organic pollutants. While advanced oxidation processes such as Fenton oxidation and ozone oxidation possess high oxidation capabilities, they suffer from drawbacks including difficulties in oxidant storage, low utilization efficiency, and high operating costs. Photoelectrocatalysis, by coupling photocatalysis and electrocatalysis, utilizes an external bias voltage to promote the separation of photogenerated carriers and reduce the probability of electron-hole recombination, thereby improving the efficiency of reactive oxygen species generation. Compared to traditional water treatment technologies, photoelectrocatalysis offers advantages such as easy catalyst recovery, no need for continuous oxidant addition, and low energy consumption.
[0004] Copper bismuthate (CuBi₂O₄) is a p-type semiconductor material with a narrow bandgap and suitable band structure, exhibiting excellent visible light response and showing high application potential in photocatalysis and photoelectrocatalysis. However, CuBi₂O₄ films still face key challenges in practical applications, such as high photogenerated carrier recombination rates and insufficient interfacial charge transport efficiency, which severely restrict further improvements in their photoelectrocatalytic performance. Summary of the Invention
[0005] To address the issue of poor photoelectrocatalytic performance of copper bismuthate p-type semiconductor materials, this invention aims to provide a copper bismuthate-based composite thin-film electrode material and its preparation method. The method involves sequentially constructing a copper bismuthate thin film layer, a cadmium sulfide layer, and an electrocatalytically active material layer on a conductive substrate. The copper bismuthate thin film layer and the cadmium sulfide layer form a pn heterojunction structure, generating a built-in electric field at the interface. This promotes spatial separation of photogenerated electrons and holes and improves carrier migration efficiency. Furthermore, the electrocatalytically active material layer is introduced onto the surface of the pn heterojunction to enhance the interfacial charge transport process and improve surface reaction kinetics. Therefore, the copper bismuthate-based composite thin-film electrode material prepared by this invention exhibits high photoelectrocatalytic activity and stability, thereby achieving efficient degradation of organic pollutants.
[0006] Based on the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a copper bismuthate-based composite thin film electrode material, comprising a conductive substrate, and a copper bismuthate thin film layer, a cadmium sulfide layer, and an electrocatalytic active material layer formed sequentially on the conductive substrate. Among them, the copper bismuthate thin film layer and the cadmium sulfide layer form a pn heterojunction structure; The electrocatalytic active material layer is dispersed and loaded on the cadmium sulfide layer in the form of nanoparticles or nanoclusters; the chemical composition of the electrocatalytic active material layer is a noble metal or its metal oxide.
[0007] This invention employs a cadmium sulfide layer, an n-type semiconductor, to be constructed on the surface of a copper bismuthate thin film, forming a pn heterojunction structure. This improves the carrier separation efficiency of CuBi₂O₄ and generates a built-in electric field at the interface, thereby promoting the spatial separation of photogenerated electrons and holes and improving carrier migration efficiency. Simultaneously, an electrocatalytically active material layer is further introduced onto the pn heterojunction surface to construct a photoelectrocatalytic electrode material with high catalytic activity and stability. This helps enhance the interfacial charge transport process and improve surface reaction kinetics, further improving the photoelectrocatalytic performance of the copper bismuthate-based composite thin film electrode material, thus achieving efficient degradation of organic pollutants.
[0008] Furthermore, the thickness of the copper bismuthate thin film layer is 460–480 nm; the thickness of the cadmium sulfide layer is 20–40 nm.
[0009] Furthermore, the precious metal is at least one of ruthenium, iridium, and platinum.
[0010] Furthermore, the conductive substrate is at least one of fluorine-doped tin oxide conductive glass, indium tin oxide conductive glass, carbon cloth, or carbon paper.
[0011] Secondly, the present invention provides a method for preparing the above-mentioned copper bismuthate-based composite thin film electrode material, comprising the following steps: S1: A copper bismuthate precursor solution is spin-coated onto a conductive substrate, and then cured and calcined to obtain a copper bismuthate thin film electrode. S2: The copper bismuthate thin film electrode is immersed in the cadmium sulfide precursor solution for chemical bath deposition reaction, and cadmium sulfide is deposited on the surface of the copper bismuthate thin film electrode. After heating and curing, the copper bismuthate / cadmium sulfide composite thin film electrode is obtained. S3: The copper bismuthate / cadmium sulfide composite thin film electrode is immersed in a noble metal precursor solution, and then dried and calcined to obtain the copper bismuthate-based composite thin film electrode material.
[0012] Preferably, the copper bismuthate precursor solution in step S1 is obtained by dissolving bismuth salt and copper salt in an organic solvent, wherein the organic solvent is composed of ethylene glycol, acetic acid and ethanol in a volume ratio of (0.5-2):(0.5-2):(0.5-2); and the concentration of bismuth salt and copper salt in the copper bismuthate precursor solution is 0.5-2.0 M. Preferably, the copper bismuthate precursor solution also contains 0.2 to 0.8 g / mL of P123, with a preferred concentration of 0.33 g / mL. P123 is a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, which increases the viscosity of the copper bismuthate precursor solution and forms a porous structure in the prepared CuBi2O4 photocathode, increasing the surface roughness of the film after cadmium sulfide deposition, which is beneficial for the loading of noble metals or their oxides on the surface.
[0013] In step S1, the amount of copper bismuthate precursor solution spin-coated onto the conductive substrate is 25–75 μL / cm. 2 The spin coating process consists of two steps: low-speed and high-speed spin coating. The first step, low-speed spin coating, has a rotation speed of 1000–2000 rpm and a time of 10–30 s. The second step, spin coating, has a rotation speed of 2500–4000 rpm and a time of 20–60 s.
[0014] In step S1, the curing parameters are 120–200 °C and the treatment time is 5–30 min; the calcination parameters are: heating to 400–550 °C at a heating rate of 2–10 °C / min and holding at that temperature for 0.5–2 h.
[0015] Preferably, the cadmium sulfide precursor solution contains 5-30 mM of cadmium salt, 0.5-2.0 M of sulfur source, and 20 wt%-35 wt% of ammonia water; the cadmium sulfide precursor solution also contains 0.2-2.0 g / L of lithium fluoride.
[0016] Preferably, the temperature of the chemical bath deposition reaction in step S2 is 50–80 °C, and the reaction time is 10–40 min; the temperature of the heating curing is 70–120 °C, and the time is 2–10 h.
[0017] Preferably, the calcination parameters in step S3 are: heating to 250-350 ℃ at a heating rate of 2-10 ℃ / min under an inert atmosphere and holding at that temperature for 1-4 h.
[0018] Preferably, the noble metal precursor is selected from at least one of ruthenium acetylacetonate, iridium acetylacetonate, or platinum acetylacetonate; the concentration of the noble metal precursor solution is 1–10 mM, and the immersion time of the copper bismuthate / cadmium sulfide composite thin film electrode in the noble metal precursor solution is 5–60 min.
[0019] Thirdly, this invention seeks to protect the application of the above-mentioned copper bismuthate-based composite thin film electrode material in the photocatalytic degradation of organic pollutants, including antibiotics, dyes, and pesticides.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention aims to improve the carrier separation efficiency of CuBi₂O₄ by constructing an n-type semiconductor layer on its surface to form a pn heterojunction structure. This generates a built-in electric field at the interface, thereby promoting the spatial separation of photogenerated electrons and holes and improving carrier migration efficiency. Simultaneously, an electrocatalytic layer is further introduced onto the pn heterojunction surface, which helps enhance the interfacial charge transport process and improve surface reaction kinetics, positively impacting photoelectrocatalytic performance. Through multilayer composite structure design and interface modulation strategies, the light absorption performance and carrier utilization efficiency of CuBi₂O₄-based materials are optimized to construct photoelectrocatalytic electrode materials with high catalytic activity and stability, thus achieving efficient degradation of organic pollutants.
[0021] This invention employs a spin-coating-annealing-calcination process to prepare a copper bismuthate thin-film electrode. Furthermore, cadmium sulfide and ruthenium are loaded onto the copper bismuthate thin-film electrode via chemical bath deposition and impregnation-calcination. Under photoelectrocatalytic conditions, the copper bismuthate-based composite thin-film electrode promotes the generation of active species, thereby achieving efficient removal of organic pollutants at relatively low bias voltages. The preparation process of this copper bismuthate-based composite thin-film electrode material is relatively simple, with low catalyst loading, high electron transfer efficiency, and good cycle stability, demonstrating promising application prospects. Attached Figure Description
[0022] Figure 1 The transient photocurrent response curves of the copper bismuthate-based composite thin film electrode materials prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 2 X-ray diffraction (XRD) and Raman spectra of the samples prepared in Example 1 and Comparative Examples 1-2; Figure 3 The X-ray photoelectron spectroscopy (XPS) spectra of C 1s and Ru 3d energy levels in the samples prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 4 The surface morphology and cross-sectional scanning electron microscope (SEM) images of the samples prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 5 The UV-Vis diffuse reflectance (UV-Vis DRS) spectra and (αhν) of the samples prepared in Example 1 and Comparative Examples 1-2 are shown. 1 / 2 -hν band structure analysis diagram; Figure 6 The graph shows the test results of charge separation efficiency and surface charge injection efficiency of the samples prepared in Example 1 and Comparative Examples 1-2; Figure 7 Electrochemical impedance phase angle test diagrams of the samples prepared in Example 1 and Comparative Examples 1-2 under applied bias conditions; Figure 8This is a comparison chart showing the performance of the samples prepared in Example 1 and Comparative Examples 1-2 in degrading the antibiotic norfloxacin under different photoelectrocatalytic conditions; Figure 9 The graph shows the total organic carbon removal rate of the samples prepared in Example 1 and Comparative Examples 1-2 after 1 hour of photoelectrocatalytic degradation of the antibiotic norfloxacin. Figure 10 The graph shows the cycle stability test results of the samples prepared in Example 1 and Comparative Examples 1-2 during the photoelectrocatalytic degradation of norfloxacin. Figure 11 The curves showing the effect of different LiF addition amounts on the photocatalytic degradation performance of NOR in the composite film; Figure 12 The effect curves of different metal elements deposited on the surface of CuBi2O4 / CdS composite thin film electrode material on the photocatalytic degradation performance of NOR are shown. Detailed Implementation
[0023] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Example
[0024] This embodiment provides a method for preparing a copper bismuthate-based composite thin-film electrode material, including the following steps: (1) 2.16 mmol of bismuth nitrate pentahydrate was dissolved in a mixed solvent of 1.0 mL acetic acid and 1.0 mL ethylene glycol and sonicated for 20 min. Then, 1.0 mL of 1.08 M copper nitrate trihydrate ethanol solution was added and sonicated for another 20 min. After that, 1.0 g of P123 was added and stirred at room temperature for 30 min to obtain the precursor solution. P123 is a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. The role of P123 is to increase the viscosity of the precursor solution and to make the prepared CuBi2O4 photocathode form a porous structure.
[0025] (2) 200 μL of the precursor solution was spin-coated onto a 2 cm × 2 cm area on the surface of FTO conductive glass. The spin-coating process consisted of two consecutive steps: the first spin-coating speed was 1500 rpm for 15 s; the second spin-coating speed was 3500 rpm for 40 s. After spin-coating, the sample was dried and cured at 150 °C for 10 min, and the spin-coating and drying / curing steps were repeated twice. The sample was then placed in a muffle furnace and heated to 450 °C at a heating rate of 5 °C / min and held at that temperature for 1 h. After natural cooling to room temperature, copper bismuthate thin film electrode material (CuBi2O4) was obtained.
[0026] (3) The copper bismuthate thin film electrode was immersed in a mixed solution containing 10 mL of cadmium nitrate tetrahydrate (15 mM), 60 mg of lithium fluoride, 13 mL of ammonia (28-30%), 6.4 mL of thiourea (1.5 M), and 70 mL of ultrapure water, and reacted in a water bath at 66 °C for 16.5 min. After the reaction, the sample was washed with deionized water and dried with nitrogen, and then cured by heating at 90 °C for 6 h. After cooling to room temperature, the copper bismuthate / cadmium sulfide composite thin film electrode material (CuBi2O4 / CdS) was obtained.
[0027] (4) The above copper bismuthate / cadmium sulfide composite thin film electrode was immersed in 10 mL of 5 mM ruthenium acetylacetone ethanol solution for 10 min. After drying at room temperature, it was placed in a tube furnace and heated to 300 °C at a heating rate of 5 °C / min under a nitrogen atmosphere and held for 2 h. After cooling to room temperature, the copper bismuthate / cadmium sulfide / ruthenium composite thin film electrode material was obtained, denoted as CuBi2O4 / CdS / Ru.
[0028] The difference between this comparative example and Example 1 is that no cadmium sulfide layer and ruthenium active component were deposited, and the prepared sample is denoted as CuBi2O4.
[0029] Its preparation method is the same as the preparation steps of the copper bismuthate thin film electrode in Example 1.
[0030] The difference between this comparative example and Example 1 is that no ruthenium active component was deposited, and the prepared sample is denoted as CuBi2O4 / CdS.
[0031] The preparation method is the same as the preparation steps of the copper bismuthate / cadmium sulfide composite thin film electrode in Example 1.
[0032] The transient photocurrent response results of the samples prepared in Example 1 and Comparative Examples 1 and 2 are as follows: Figure 1 As shown in the figure. The results show that the photocurrent density of the composite thin-film electrode material is significantly improved after depositing the cadmium sulfide layer and the ruthenium active component. In a 0.5 M Na₂SO₄ electrolyte solution with a light intensity of 100 mW / cm², the photocurrent density is significantly increased. 2Under an applied bias voltage of -0.2 V vs. SHE, the composite thin-film electrode can generate approximately 0.075 mA / cm². 2 The photocurrent density.
[0033] The XRD and Raman spectra of the samples prepared in Example 1 and Comparative Examples 1-2 are as follows: Figure 2 As shown. The results indicate that characteristic diffraction peaks of the tetragonal phase of copper bismuthate can be observed in the sample, along with diffraction peaks belonging to the hexagonal cadmium sulfide (100) crystal plane, indicating that the cadmium sulfide layer was successfully formed on the surface of the copper bismuthate film.
[0034] XPS results of the samples prepared in Example 1 and Comparative Examples 1-2 are as follows: Figure 3 As shown. The results indicate that the sample contains substances belonging to Ru. 0 and Ru 4+ The characteristic peaks indicate that the ruthenium active component was successfully loaded onto the surface of the composite film.
[0035] The SEM results of the samples prepared in Example 1 and Comparative Examples 1-2 are as follows: Figure 4 As shown, where, Figure 4 (a) and (d) are surface and cross-sectional morphology diagrams of CuBi2O4; Figure 4 (b) and (e) are surface and cross-sectional morphology diagrams of CuBi2O4 / CdS; Figure 4 (c) and (f) are surface and cross-sectional morphology diagrams of CuBi2O4 / CdS / Ru; Figure 4 Surface morphology shows that the copper bismuthate film prepared by spin-coating and calcination has a porous structure. The surface roughness of the film increases after cadmium sulfide deposition, and the film density is improved after further loading with ruthenium active components. Cross-sectional SEM results show that the thickness of the copper bismuthate film in this embodiment is approximately 470±10 nm, and the total thickness after cadmium sulfide deposition is approximately 500±10 nm.
[0036] Figure 5 The UV-Vis diffuse reflectance spectra and band structure analysis results of the samples prepared in Example 1 and Comparative Examples 1-2 are shown. The results indicate that, compared with CuBi2O4 and CuBi2O4 / CdS, the CuBi2O4 / CdS / Ru composite thin film electrode material prepared in Example 1 has a more suitable band structure, which is beneficial for promoting the participation of photogenerated electrons in the reduction reaction.
[0037] Figure 6 The results show the charge separation efficiency and surface charge injection efficiency of the composite thin-film electrode material. The results indicate that the cadmium sulfide layer helps improve the bulk charge separation efficiency, while further loading of electrocatalytically active components can improve the surface reaction efficiency.
[0038] Figure 7The results show the electrochemical impedance phase angle measurements under different bias conditions. The results indicate that the CuBi₂O₄ / CdS / Ru composite thin film electrode material exhibits superior interfacial charge transport behavior.
[0039] This embodiment is used to evaluate the photoelectrocatalytic degradation performance of the copper bismuthate-based composite thin film electrode material prepared in Example 1 on organic pollutants.
[0040] A mixed solution containing 5 mg / L norfloxacin (NOR) and 0.5 M Na₂SO₄ electrolyte was added to a rectangular quartz reactor, and a degradation experiment was conducted under simulated sunlight conditions to evaluate the photoelectrocatalytic performance of the CuBi₂O₄ / CdS / Ru composite thin-film electrode as a photocathode in Example 1. A 300 W xenon lamp equipped with an AM1.5G filter was used as the light source, with an applied bias voltage of -0.2 V vs. SHE, and the distance between the light source and the photocathode was 10 cm.
[0041] The photoelectrocatalytic degradation reaction was initiated by simultaneously turning on the light source and the external power supply. During the reaction, samples were taken periodically using a syringe, filtered through a 0.22 μm filter membrane, and the changes in NOR concentration in the solution were determined by high-performance liquid chromatography.
[0042] The degradation performance of NOR in Examples 1 and Comparative Examples 1-2 under photocatalytic (PC), electrocatalytic (EC), and photoelectrocatalytic (PEC) conditions is compared as follows: Figure 8 As shown in (a), (b), and (c) of the figure. The results show that after constructing the cadmium sulfide layer, the CuBi2O4 / CdS composite thin film electrode material exhibits improved performance in photocatalytic degradation of NOR; the composite electrode can achieve a photocatalytic degradation rate of 70% for NOR within 1 hour, which is about 10% higher than that of a single CuBi2O4 photocathode, while the improvement in the efficiency of electrocatalytic degradation of NOR is relatively small; further introducing the electrocatalytically active component Ru onto the surface of the CuBi2O4 / CdS composite thin film electrode material does not significantly improve the photocatalytic degradation efficiency of NOR, while the efficiency of electrocatalytic degradation of NOR increases from about 50% to 60% within 1 hour. Compared with Comparative Examples 1 and 2, the CuBi2O4 / CdS / Ru composite thin film electrode material prepared in Example 1 exhibits relatively high degradation efficiency for NOR under photoelectrocatalytic conditions, achieving a removal rate of over 90% within 1 hour.
[0043] The total organic carbon (TOC) removal rates of Examples 1 and Comparative Examples 1-2 after 1 h of photoelectrocatalytic degradation of NOR are as follows: Figure 9As shown, CBO is an abbreviation for CuBi2O4. The TOC removal rates after 1 h of photoelectrocatalytic NOR reaction of CBO, CBO / CdS, and CBO / CdS / Ru were 7.6%, 15.4%, and 23.7%, respectively. The results indicate that the composite thin-film electrode material of Example 1 can achieve high mineralization efficiency of organic pollutants, suggesting that constructing a composite structure is beneficial to improving the deep oxidation capability of the electrode material.
[0044] The stability test results of the samples prepared in Example 1 and Comparative Examples 1-2 during 5 photoelectrocatalytic degradation NOR cycles are as follows: Figure 10 As shown in the figure. The results show that the composite thin film electrode material prepared in Example 1 can still maintain high catalytic activity during repeated recycling, indicating that the composite structure has good cycling stability and structural stability. Example
[0045] During the deposition of CdS on the surface of copper bismuthate thin films, the addition of LiF to the CdS reaction precursor solution can improve the deposition uniformity of CdS on the surface of copper bismuthate thin films, prevent excessive aggregation of CdS on the surface of copper bismuthate thin films, and improve the photoelectrocatalytic performance of the final composite thin film electrode material.
[0046] Compared to Example 1, this example only adjusts the amount of lithium fluoride added in the reaction system of step (3) from 60 mg to 0 mg, 30 mg, and 90 mg in sequence, where 0 mg indicates that no LiF was added to the reaction system. The rest of the preparation methods are the same as in Example 1.
[0047] Referring to the photocatalytic degradation experiment of norfloxacin (NOR) in Example 2, the photocatalytic degradation performance of CuBi2O4 / CdS / Ru composite thin film electrode materials prepared with different amounts of LiF in this example on NOR was analyzed. The results are as follows: Figure 11 As shown, both excessively low and excessively high levels of LiF in the CdS precursor solution are detrimental to the photocatalytic degradation of NOR by the final product CuBi2O4 / CdS / Ru composite thin film electrode material. However, the CuBi2O4 / CdS / Ru composite thin film electrode material exhibits superior NOR photoelectrocatalytic degradation efficiency only when the amount of LiF added in the CdS precursor solution is 60 mg (approximately 0.375 g / L). Example
[0048] The purpose of this embodiment is to analyze the effect of different metal elements deposited on the surface of copper bismuthate / cadmium sulfide composite thin film electrode material on the electrocatalytic performance of the thin film.
[0049] Compared to Example 1, in step (4) of this example, "ruthenium acetylacetonate" is replaced with manganese acetylacetonate, iron acetylacetonate, cobalt acetylacetonate, and nickel acetylacetonate in sequence to construct CuBi2O4 / CdS / Mn, CuBi2O4 / CdS / Fe, CuBi2O4 / CdS / Co, and CuBi2O4 / CdS / Ni composite thin film electrode materials respectively.
[0050] Referring to the photocatalytic degradation experiment of norfloxacin (NOR) in Example 2, the photoelectrocatalytic degradation effect of different metal elements deposited on the CuBi2O4 / CdS composite film surface in this example on NOR was analyzed. Figure 12 As shown, compared with deposited metal elements Mn, Fe, Co, and Ni, CuBi2O4 / CdS / Ru composite film electrode materials with noble metal Ru deposited on the surface of CuBi2O4 / CdS composite film have relatively better NOR degradation efficiency under photoelectrocatalytic conditions.
[0051] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0052] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. A copper bismuthate-based composite thin-film electrode material, characterized in that, The copper bismuthate-based composite thin film electrode material includes a conductive substrate, and a copper bismuthate thin film layer, a cadmium sulfide layer, and an electrocatalytic active material layer formed sequentially on the conductive substrate. The copper bismuthate thin film layer and the cadmium sulfide layer form a pn heterojunction structure; The electrocatalytic active material layer is dispersed and loaded on the cadmium sulfide layer in the form of nanoparticles or nanoclusters; the chemical composition of the electrocatalytic active material layer is a noble metal or its metal oxide.
2. The copper bismuthate-based composite thin film electrode material according to claim 1, characterized in that, The thickness of the copper bismuthate thin film layer is 460–480 nm; the thickness of the cadmium sulfide layer is 20–40 nm.
3. The copper bismuthate-based composite thin-film electrode material according to claim 1, characterized in that, The precious metal is at least one of ruthenium, iridium, and platinum.
4. The copper bismuthate-based composite thin-film electrode material according to claim 1, characterized in that, The conductive substrate is at least one of fluorine-doped tin oxide conductive glass, indium tin oxide conductive glass, carbon cloth, or carbon paper.
5. A method for preparing the copper bismuthate-based composite thin-film electrode material according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1: A copper bismuthate precursor solution is spin-coated onto a conductive substrate, and then cured and calcined to obtain a copper bismuthate thin film electrode. S2: The copper bismuthate thin film electrode is immersed in a cadmium sulfide precursor solution for chemical bath deposition reaction, and cadmium sulfide is deposited on the surface of the copper bismuthate thin film electrode. After heating and curing, a copper bismuthate / cadmium sulfide composite thin film electrode is obtained. S3: The copper bismuthate / cadmium sulfide composite thin film electrode is immersed in a solution containing a noble metal precursor, and then dried and calcined to obtain a copper bismuthate-based composite thin film electrode material.
6. The method for preparing copper bismuthate-based composite thin film electrode material according to claim 5, characterized in that, The copper bismuthate precursor solution in step S1 is obtained by dissolving bismuth salt and copper salt in an organic solvent, wherein the organic solvent is composed of ethylene glycol, acetic acid and ethanol in a volume ratio of (0.5-2):(0.5-2):(0.5-2); the concentration of bismuth salt and copper salt in the copper bismuthate precursor solution is 0.5-2.0 M. The copper bismuthate precursor solution also contains 0.2–0.8 g / mL of P123; The curing parameters in step S1 are 120–200 °C and the treatment time is 5–30 min; the calcination parameters are: heating to 400–550 °C at a heating rate of 2–10 °C / min and holding at that temperature for 0.5–2 h.
7. The method for preparing copper bismuthate-based composite thin film electrode material according to claim 5, characterized in that, The cadmium sulfide precursor solution in step S2 contains 5-30 mM cadmium salt, 0.5-2.0 M sulfur source, and 20 wt%-35 wt% ammonia water; the cadmium sulfide precursor solution also contains 0.2-2.0 g / L lithium fluoride.
8. The method for preparing copper bismuthate-based composite thin film electrode material according to claim 5, characterized in that, The temperature of the chemical bath deposition reaction in step S2 is 50–80 °C, and the reaction time is 10–40 min; the temperature of the heating curing is 70–120 °C, and the time is 2–10 h.
9. The method for preparing copper bismuthate-based composite thin film electrode material according to claim 5, characterized in that, The noble metal precursor in step S3 is selected from at least one of ruthenium acetylacetonate, iridium acetylacetonate, or platinum acetylacetonate; the concentration of the noble metal precursor solution is 1-10 mM, and the immersion time is 5-60 min. The calcination parameters in step S3 are: heating to 250-350 ℃ at a heating rate of 2-10 ℃ / min under an inert atmosphere and holding at that temperature for 1-4 h.
10. The application of the copper bismuthate-based composite thin film electrode material according to any one of claims 1 to 4 in the photocatalytic degradation of organic pollutants, wherein the organic pollutants include antibiotics, dyes, and pesticides.