A full-spectrum response photoelectrode material and a preparation method thereof

Abstract

This invention relates to the field of materials preparation technology, and in particular to a full-spectrum responsive photoelectrode material and its preparation method. The preparation method includes the following steps: adding a Cu source and CO(NH2)2 to water and mixing to obtain a mixed solution; placing a conductive substrate in the mixed solution for a hydrothermal reaction; washing and drying the product obtained from the hydrothermal reaction to obtain the photoelectrode material. The preparation method of this invention is mild, simple to operate, and exhibits significant photoelectrocatalytic degradation of pollutants, good stability, and low cost, making it suitable for industrial production and application. The sample prepared by this invention has a wider spectral response range, improving the light utilization rate of the photoelectrode and the performance of photoelectrocatalytic degradation of pollutants, thereby enhancing photoelectrocatalytic activity and effectively degrading imidacloprid within 120 minutes.

Description

Technical Field

[0001] This invention relates to the field of materials preparation technology, and in particular to a full-spectrum responsive photoelectrode material and its preparation method. Background Technology

[0002] Currently, conventional organic wastewater treatment technologies in China are mainly divided into biological, physical, and chemical methods. Among them, photocatalysis technology has received considerable attention in the wastewater treatment field in recent years due to its advantages such as simple operation, high treatment efficiency, good stability, and high product mineralization. However, traditional photocatalytic materials suffer from a narrow light absorption wavelength range, primarily utilizing the ultraviolet (5%) and visible light (46%) of sunlight, while making limited use of the infrared (49%). Current research on infrared photocatalysts mainly focuses on rare earth and noble metal elements such as CaF2:yb. 3+ / Er 3+ NaYF4:yb 3+ / Er 3+ AgS2, Tm 3+ / TiO2, infrared-responsive rare earth and noble metal catalysts solve the problem of narrow light absorption wavelength range of traditional photocatalysts, but their high cost hinders large-scale production. CN119702023 discloses a copper-based full-spectrum responsive photocatalyst, but the leaching of phosphorus in Cu2(OH)PO4 catalyst may lead to excessive phosphorus levels in the treated wastewater, causing eutrophication. Cu3(OH)4SO4, which uses sulfate instead of phosphate, has a similar octahedral structure to Cu2(OH)PO4 (Chemistry A European J 13583-13587 2015-09-21) and is also responsive to infrared light, but powdered catalysts suffer from difficulties in recovery and easy recombination of photogenerated carriers. Photoelectrocatalysis (PEC) combines electrochemistry and photocatalysis, using photocatalysts as photoelectrodes to facilitate catalyst recovery. By applying an external voltage, photogenerated electrons and holes are rapidly and completely separated, significantly improving the photocatalytic reaction rate. Currently used TiO2 photoelectrodes have the problem of a narrow light response range, concentrated in the ultraviolet and visible light range, resulting in insufficient utilization of sunlight.

[0003] In general, the current photoelectrode fabrication process suffers from problems such as high cost, unstable performance, and low light energy utilization. Therefore, it is of great significance to develop a novel, efficient, and low-cost photoelectrode with full-spectrum response capability using Cu3(OH)4SO4 and its fabrication method. Summary of the Invention

[0004] The purpose of this invention is to provide a full-spectrum responsive photoelectrode material, its preparation method, and its application. The full-spectrum responsive photoelectrode is synthesized by a hydrothermal method, which improves the utilization rate of the light source, expands the spectral response range of the material, enhances the photoelectrocatalytic activity, and improves the photoelectrocatalytic degradation ability of pollutants.

[0005] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of this invention is a method for preparing a full-spectrum responsive photoelectrode material, comprising the following steps: Cu source and CO(NH2)2 are added to water and mixed well to obtain a mixed solution; The conductive substrate is placed in the mixture for a hydrothermal reaction. The product obtained from the hydrothermal reaction is washed and dried to obtain the photoelectrode material.

[0006] The second technical solution of the present invention is a photoelectrode material prepared by the above-mentioned preparation method.

[0007] The third technical solution of the present invention is the application of the above-mentioned photoelectrode material in the degradation of organic pollutants in wastewater.

[0008] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention prepares a photoelectrode by mixing Cu source (CuSO4·5H2O), CO(NH2)2 and water and adding them to a conductive substrate (nickel foam). The conditions are mild, the operation is simple, the photoelectrocatalytic degradation of pollutants is significant, the stability is good and the cost is low, making it suitable for industrial production and application. (2) The sample prepared by the present invention has a larger spectral response range, which improves the light utilization rate of the photoelectrode and the performance of photoelectrocatalytic degradation of pollutants, thereby improving the photoelectrocatalytic activity. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 The XRD diffraction pattern of the photoelectrode material in Example 1 is shown below. Figure 2 SEM image of the photoelectrode material in Example 2; Figure 3 The image shows the full-spectral diffuse reflectance of the photoelectrode material in Example 2. Figure 4 The graph shows the light conversion efficiency of the photoelectrode material in Example 2. Figure 5 The graph shows the degradation effect of the photoelectrode material in Example 3 on imidacloprid in wastewater under different light conditions. Figure 6 The graph shows the degradation effect of the photoelectrode material in Example 3 on imidacloprid in wastewater, whether or not it is energized. Detailed Implementation

[0011] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0012] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0013] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0014] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0015] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0016] The first aspect of this invention provides a method for preparing a full-spectrum responsive photoelectrode material, comprising the following steps: Cu source and CO(NH2)2 are added to water and mixed well to obtain a mixed solution; The conductive substrate is placed in the mixture for a hydrothermal reaction. The product obtained from the hydrothermal reaction is washed and dried to obtain the photoelectrode material.

[0017] In a preferred embodiment of the present invention, the Cu source is CuSO4·5H2O.

[0018] In a preferred embodiment of the present invention, the molar ratio of the Cu source to the CO(NH2)2 is (0.5~3):1. Optionally, the molar ratio of the Cu source to the CO(NH2)2 is 0.5:1, 1:1, 2:1, 3:1 or any value between the two aforementioned ratios.

[0019] In this invention, if the ratio of Cu source to CO(NH2)2 exceeds the parameter range described above, it will result in insufficient material loading on the nickel foam surface. Therefore, this invention preferably limits the molar ratio of Cu source to CO(NH2)2 to (0.5~3):1, and more preferably to (0.5~2):1.

[0020] In a preferred embodiment of the present invention, the concentration of Cu source in the mixture is 0.09~0.13 mol / L. Optionally, the concentration of Cu source in the mixture is 0.09, 0.10, 0.11, 0.12, 0.13 mol / L or any value between the two aforementioned values.

[0021] In a preferred embodiment of the present invention, the conditions for the hydrothermal reaction are set as follows: reaction at 120~140℃ for 8~10 hours. Optionally, the temperature of the hydrothermal reaction is 120, 130, 140℃ or any value between the two aforementioned values, and the time of the hydrothermal reaction is 8, 9, 10 or any value between the two aforementioned values. In this invention, if the temperature of the hydrothermal reaction is too high or the time is too long, the plasticity of the nickel foam will decrease; if the temperature of the hydrothermal reaction is too low or the time is too short, the material loaded on the surface of the nickel foam will be too little.

[0022] In a preferred embodiment of the present invention, the drying conditions are set as follows: drying at 50~80℃ for 6~12 hours.

[0023] In a preferred embodiment of the present invention, the conductive substrate is nickel foam; the pore size of the nickel foam is 0.1 mm to 5 mm (5 to 10 ppi), and the porosity is 60% to 90%.

[0024] A second aspect of the present invention provides a photoelectrode material prepared using the above-described preparation method.

[0025] A third aspect of the present invention provides the application of the above-mentioned photoelectrode material in the degradation of organic pollutants in wastewater.

[0026] In a preferred embodiment of the present invention, the organic pollutant is imidacloprid; the concentration of the organic pollutant in the wastewater is 10~20 mg / L.

[0027] In a preferred embodiment of the present invention, the degradation conditions are set as follows: a heterogeneous photoelectrocatalytic system is constructed, using a photoelectrode material as the working electrode, a platinum electrode as the counter electrode, a xenon lamp light source system to simulate sunlight or sunlight as the light source, and Na2SO4 and H2O2 are added to the wastewater to achieve the degradation of organic pollutants; The concentration of Na2SO4 in the wastewater was 50 mM, and the concentration of H2O2 was 10 mM; the current density was 30 mA / cm². 2 pH=5.

[0028] The preparation method of this invention is mild and simple to operate, with significant effect on photoelectrocatalytic degradation of pollutants, good stability and low cost, making it suitable for industrial production and application. The sample prepared by this invention has a wider spectral response range, improves the light utilization rate of the photoelectrode and the performance of photoelectrocatalytic degradation of pollutants, thereby improving the photoelectrocatalytic activity, and can effectively degrade imidacloprid within 120 min.

[0029] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0030] The nickel foam used in this embodiment of the invention was purchased from Kunshan Ansu Electronic Materials, and its size is 2×1cm. 2 Thickness 1mm, pore size 0.1mm~5mm (5~10ppi), porosity 60%~90%.

[0031] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0032] Example 1 Mix 8 mmol CuSO4·5H2O and 4 mmol CO(NH2)2 with 65 mL of water at a molar ratio of 2:1, and stir at 600 rpm for 20 min until the solution becomes a homogenate. Then add 2 × 1 cm⁻¹ water. 2 Three pieces of nickel foam were placed in a homogeneous reactor and hydrothermally reacted at 120°C for 10 hours to obtain a sheet-like material. The product was then washed three times with distilled water to remove impurities and placed in a vacuum drying oven to dry at 60°C for 6 hours to obtain the Cu3(OH)4SO4 / NF photoelectrode.

[0033] Example 2 Mix 8 mmol CuSO4·5H2O and 6 mmol CO(NH2)2 in a molar ratio of 4:3 with 65 mL of water, and stir at 800 rpm for 25 min until the solution becomes a homogenate. Then add 2 × 1 cm⁻¹ water. 2Two pieces of nickel foam were placed in a homogeneous reactor and hydrothermally reacted at 140°C for 8 hours to obtain a sheet-like material. The product was then washed three times with distilled water to remove impurities and placed in a vacuum drying oven to dry at 60°C for 6 hours to obtain the Cu3(OH)4SO4 / NF photoelectrode.

[0034] Example 3 Mix 6 mmol CuSO4·5H2O and 12 mmol CO(NH2)2 in a molar ratio of 1:2 with 65 mL of water, and stir at 800 rpm for 25 min until the solution becomes a homogenate. Then add 2 × 1 cm⁻¹ water. 2 Two pieces of nickel foam were placed in a homogeneous reactor and hydrothermally reacted at 120°C for 10 hours to obtain a sheet. The product was then washed three times with distilled water to remove impurities and placed in a vacuum drying oven to dry at 60°C for 6 hours to obtain the Cu3(OH)4SO4 / NF photoelectrode.

[0035] Example 4 Mix 6 mmol CuSO4·5H2O and 6 mmol CO(NH2)2 in a molar ratio of 1:1 with 65 mL of water, and stir at 800 rpm for 25 min until the solution becomes a homogenate. Then add 2 × 1 cm⁻¹ water. 2 Two pieces of nickel foam were placed in a homogeneous reactor and hydrothermally reacted at 140°C for 8 hours to obtain a sheet-like material. The product was then washed three times with distilled water to remove impurities and placed in a vacuum drying oven to dry at 60°C for 6 hours to obtain the Cu3(OH)4SO4 / NF photoelectrode material.

[0036] Effect test: The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 1 was examined by X-ray diffraction. Figure 1 As shown.

[0037] from Figure 1 As can be seen from the data, the diffraction peaks of the Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 1 of this application have a good correspondence with the typical Cu3(OH)4SO4 material phase.

[0038] The diffraction peaks of the Cu3(OH)4SO4 / NF photoelectrode materials prepared in Examples 2-4 show a good correspondence with the typical Cu3(OH)4SO4 material phase, indicating that the Cu3(OH)4SO4 / NF photoelectrode material was successfully prepared under the reaction conditions of the present invention.

[0039] The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 2 was observed using a scanning electron microscope, as shown... Figure 2 As shown.

[0040] from Figure 2 As can be seen from Example 2 of this application, the Cu3(OH)4SO4 / NF photoelectrode material is uniformly distributed on the surface of nickel foam, which can provide more active sites.

[0041] The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 2 was subjected to total diffuse reflection. The absorbance of the material is as follows: Figure 3 As shown. From Figure 3 As can be seen from the data, the absorption peaks of the Cu3(OH)4SO4 / NF photoelectrode material are present in the entire spectrum, indicating that the material has a full-spectrum response energy.

[0042] The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 2 was subjected to linear voltammetry curves under illumination (test conditions: voltage range of 0-1.7 V, power density of 100 mW / cm²). -2 (Measured under sunlight), the light conversion efficiency of the material is as follows: Figure 4 As shown. From Figure 4 As can be seen, the photoconversion efficiency of Cu3(OH)4SO4 / NF photoelectrode material reaches its maximum of 0.0211% at 1.234 V vs. Ag / AgCl, indicating that the photoelectrode material has good photogenerated carrier performance.

[0043] The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 3 was used to degrade imidacloprid in wastewater under different light conditions. The test method is as follows: A heterogeneous photoelectrocatalytic system was constructed, using the photoelectrode as the working electrode and a platinum electrode as the counter electrode. The degradation experiment was carried out in a quartz electrolytic cell containing 100 ml of wastewater, which contained 15 mg / L imidacloprid, 50 mM Na2SO4, and 10 mM H2O2. A xenon lamp light source system was used to simulate sunlight for the experiment, and different light source types were tested using filters. The current density was 30 mA / cm². 2 pH 5. Degradation effect as follows Figure 5 As shown.

[0044] from Figure 5As can be seen, after 120 min of degradation, the degradation efficiency of Cu3(OH)4SO4 / NF photoelectrode for imidacloprid in wastewater was 68% under no light conditions, 74% under infrared light conditions, 80% under visible light conditions, and 99% under sunlight conditions. This demonstrates that the Cu3(OH)4SO4 / NF photoelectrode prepared in this application exhibits excellent photoelectrocatalytic degradation performance.

[0045] The Cu3(OH)4SO4 / NF photoelectrodes prepared in Examples 1, 2, and 4 were subjected to the same tests as in Example 3. The results showed that there was no significant difference in degradation efficiency among Examples 1, 2, 3, and 4 after 120 min of degradation.

[0046] The Cu3(OH)4SO4 / NF photoelectrode material prepared in Example 3 was used to test the degradation of imidacloprid in wastewater under different working electrodes. The test method is as follows: A heterogeneous photoelectrocatalytic system was constructed using different working electrodes. The photoelectrode (PER) or nickel foam (NF) was used as the working electrode, and a platinum electrode was used as the counter electrode. The degradation experiment was carried out in a quartz electrolytic cell containing 100 ml of wastewater, which contained 15 mg / L imidacloprid, 50 mM Na2SO4, and 10 mM H2O2. A xenon lamp light source system was used to simulate sunlight for the experiment, with a current density of 30 mA / cm². 2 pH 5. Degradation effect as follows Figure 6 As shown. From Figure 6 As can be seen, at a degradation time of 120 min, the degradation efficiency of Cu3(OH)4SO4 / NF photoelectrode (PER) for imidacloprid in wastewater under photoelectrocatalytic conditions was 99%, while the degradation efficiency of nickel foam electrode (NF) for imidacloprid in wastewater was only 71%. This shows that the use of photoelectrode can improve the degradation efficiency of imidacloprid in wastewater.

[0047] The Cu3(OH)4SO4 / NF photoelectrodes prepared in Examples 1, 2, and 4 were subjected to the same tests as in Example 3. The results showed that, after 120 min of degradation, under light-only conditions, there was no significant difference in degradation efficiency among Examples 1, 2, 3, and 4.

[0048] As can be seen from the above embodiments, the present invention provides a method for preparing a photoelectrode material with full-spectrum response capability and its application, comprising the following steps: mixing CuSO4·5H2O, CO(NH2)2 and water, adding washed nickel foam, and placing it in a homogeneous reactor for hydrothermal reaction to obtain a sheet-like material; drying the sheet-like material yields the photoelectrode material. The present invention uses a hydrothermal method to prepare Cu3(OH)4SO4 / NF photoelectrode by mixing CuSO4·5H2O, CO(NH2)2 solution and water, adding washed nickel foam, and then using the hydrothermal method. This method is mild, simple to operate, and exhibits significant photoelectrocatalytic degradation of pollutants, good stability, and low cost. It does not require the introduction of rare earth metals and is suitable for industrial production and application. The sample prepared by the present invention has a larger absorbable wavelength, improving the light energy utilization rate of the photoelectrode and the performance of photoelectrocatalytic degradation of pollutants, thereby enhancing photocatalytic activity.

[0049] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method of preparing a photoelectrode material with a full spectral response, characterized in that, Includes the following steps: Cu source and CO(NH2)2 are added to water and mixed well to obtain a mixed solution; The conductive substrate is placed in the mixture for a hydrothermal reaction. The product obtained from the hydrothermal reaction is washed and dried to obtain the photoelectrode material.

2. The production method according to claim 1, characterized by, The Cu source is CuSO4·5H2O.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the Cu source to the CO(NH2)2 is (0.5~3):

1.

4. The preparation method according to claim 1, characterized in that, The concentration of Cu source in the mixture is 0.09~0.13 mol / L.

5. The preparation method according to claim 1, characterized in that, The hydrothermal reaction conditions are set as follows: 120~140℃ for 8~10 hours.

6. The preparation method according to claim 1, characterized in that, The conductive substrate is nickel foam; the pore size of the nickel foam is 0.1 mm to 5 mm, and the porosity is 60% to 90%.

7. A photoelectrode material prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the photoelectrode material as described in claim 7 in the degradation of organic pollutants in wastewater.

9. The application according to claim 8, characterized in that, The organic pollutant is imidacloprid; the concentration of the organic pollutant in the wastewater is 10~20 mg / L.

10. The application according to claim 8, characterized in that, The degradation conditions are set as follows: a heterogeneous photoelectrocatalytic system is constructed, using a photoelectrode material as the working electrode, a platinum electrode as the counter electrode, and a xenon lamp light source system to simulate sunlight or use sunlight as the light source. Na2SO4 and H2O2 are added to the wastewater to achieve the degradation of organic pollutants. The concentration of Na2SO4 in the wastewater is 50 mM, and the concentration of H2O2 is 10 mM.

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