A method for oxidizing water to produce hydrogen peroxide in a non-carbonate system by using a tablet cupric subcarbonate anode and its application

Abstract

The present invention belongs to the technical field of water oxidation to produce hydrogen peroxide, and specifically relates to a method for producing hydrogen peroxide by oxidizing water in a non-carbonate system using a compressed basic copper carbonate anode and its application. In order to develop a method that can electrooxidize water into hydrogen peroxide in a non-alkaline and bicarbonate-free electrolyte, the present invention uses compressed basic copper carbonate as an anode and a Na2SO4 solution as an electrolyte to efficiently produce hydrogen peroxide in situ in a Na2SO4 electrolyte via a two-electron water oxidation pathway. The compressed basic copper carbonate has good stability, which is conducive to water oxidation to produce hydrogen peroxide, and the electrolyte solution of the non-carbonate system can effectively reduce the decomposition of hydrogen peroxide in the electrolyte solution, thereby achieving efficient water oxidation to produce hydrogen peroxide. The method of the present invention does not require pH adjustment and does not require the participation of carbonates, providing a new research idea for the electrooxidation of hydrogen peroxide in water bodies under neutral and acidic environments and the degradation of antibiotic pollutants.

Description

Technical Field

[0001] The invention belongs to the technical field of water oxidation to produce hydrogen peroxide, and particularly relates to a method for producing hydrogen peroxide by oxidizing water in a non-carbonate system through a pressed basic copper carbonate anode and an application thereof. Background Art

[0002] Hydrogen peroxide (H2O2) is a green energy source that has attracted widespread attention in fields such as chemical manufacturing, biological and medical engineering, energy technology, and environmental remediation. In recent years, developing efficient H2O2 synthesis pathways has become one of the most pressing issues. The earliest H2O2 synthesis methods involved direct synthesis from H2 and O2. However, this approach presents significant safety risks due to the unsafe range of H2 in the gas mixture (4-94 mol% H2). Currently, 95% of H2O2 is produced via the anthraquinone process (AQ). However, this method requires large-scale infrastructure and suffers from significant energy waste, making it suitable only for large-scale plant production. Furthermore, H2O2 purification and transportation remain challenges, and bulk transportation poses safety risks due to its instability. In recent years, in situ production of hydrogen peroxide has attracted increasing attention. Among these, electrocatalytic in situ synthesis of hydrogen peroxide has become a promising alternative due to its advantages such as safe operation, mild reaction conditions, on-demand production, and inexpensive raw materials.

[0003] The electrocatalytic synthesis of hydrogen peroxide can be achieved through two pathways: two-electron cathode oxygen reduction reaction (2e - ORR and two-electron anodic water oxidation reaction (2e - WOR). Among them, 2e - The ORR pathway has been widely studied, but this method requires oxygen as a raw material. Due to the low solubility of oxygen in water, a pumping device is inevitably required throughout the reaction process, resulting in excessive energy consumption and cost. In addition, the low oxygen utilization efficiency (<1%) also leads to energy waste. In contrast, 2e - WOR does not require oxygen and is not affected by oxygen solubility and diffusion. In addition, hydrogen (H2), a green energy source, can also be obtained simultaneously during the water electrolysis process (Equation (1)).

[0004] H2O→O2↑+H2↑ (1).

[0005] Currently, through 2e - The most commonly used electrolyte in WOR electrosynthesis of H2O2 is KHCO3 solution. In the KHCO3 electrolyte system, the yield of H2O2 is relatively high, reaching 4584 μmol·h -1 , while the highest yield in neutral electrolysis is only 2.2794 μmol h-1 Generally speaking, carbonates have both advantages and disadvantages. On the one hand, they are beneficial to the - WOR pathway synthesizes H2O2. For example, studies have found that in the process of producing hydrogen peroxide by oxidation of bicarbonate water, HCO3 - Oxidized to HCO4 at the anode - or C2O6 2- intermediates, which in turn oxidize water to hydrogen peroxide and back to HCO3 - Studies have also found that BiVO4 with different refractive index planes has different performance in water oxidation to produce hydrogen peroxide. This is because BiVO4 with high index planes is more conducive to HCO3 - On the other hand, bicarbonate electrolytes also have obvious disadvantages. First, bicarbonate can cause the decomposition of hydrogen peroxide molecules, resulting in low hydrogen peroxide generation efficiency. Because bicarbonate can react with ·OH to produce water and ·CO3 - Free radicals, and react with hydrogen peroxide to produce water and HCO4 - Moreover, carbonates and bicarbonates can react with hydroxyl radicals to generate CO3 - , while CO3 - It consumes hydrogen peroxide to generate bicarbonate and HO2·, which can react with CO3 - The reaction generates carbonates, that is, the presence of carbonates and bicarbonates will decompose the generated hydrogen peroxide. In addition, some applications of hydrogen peroxide in the environmental field require an acidic to neutral environment. For example, the pH value of tetracycline degradation by H2O2 is 6, and the hydrogen peroxide degradation process related to iron catalysts tends to be in a neutral pH environment. Therefore, the strong alkaline environmental characteristics of the bicarbonate system will greatly limit its application. Therefore, it is necessary to develop a method that can electrooxidize water to hydrogen peroxide in an acidic or neutral electrolyte that does not require bicarbonate. Summary of the Invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes a method for oxidizing water to produce hydrogen peroxide in a non-carbonate system using a compressed basic copper carbonate anode. In the process of catalyzing the oxidation of water to produce hydrogen peroxide in a Na2SO4 electrolyte solution using the compressed basic copper carbonate as an anode, there is no need to additionally adjust the pH of the electrolyte solution to a strong alkaline state, nor is there a need to use a bicarbonate electrolyte solution.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The invention provides a method for producing hydrogen peroxide by oxidizing water in a non-carbonate system, wherein compressed basic copper carbonate is used as an anode and a Na2SO4 solution is used as an electrolyte to electrocatalyze water oxidation to produce hydrogen peroxide.

[0009] Preferably, the preparation method of the tableted basic copper carbonate is: Cu2(OH)2CO3 and PTFE are mixed to form a slurry, which is then added into a mold after drying and tableted.

[0010] More preferably, the PTFE is a 60% PTFE solution, and the material-liquid ratio of Cu2(OH)2CO3 to PTFE solution is 0.05-2 mL / g.

[0011] The present invention proposes a method for producing hydrogen peroxide by water oxidation using a compressed basic copper carbonate anode in a neutral, non-carbonate electrolyte Na2SO4 solution. The compressed basic copper carbonate anode material is used to efficiently produce hydrogen peroxide in situ in a Na2SO4 electrolyte via a two-electron water oxidation pathway. Furthermore, the compressed basic copper carbonate anode exhibits better water oxidation performance and stability for producing hydrogen peroxide than a coated basic copper carbonate anode. This is because the problem of easy detachment from the carbon paper substrate is resolved, thereby facilitating water oxidation to produce hydrogen peroxide and successfully producing hydrogen peroxide in a neutral electrolyte solution. Furthermore, the non-carbonate electrolyte solution can effectively reduce the decomposition of hydrogen peroxide in the electrolyte solution, thereby achieving efficient water oxidation to produce hydrogen peroxide. Furthermore, the method of the present invention does not require pH adjustment or the presence of carbonates, providing a new research approach for the electrooxidation of hydrogen peroxide in aqueous solutions under neutral and acidic conditions.

[0012] More preferably, the material-liquid ratio of Cu2(OH)2CO3 and PTFE solution is 0.25 mL / g.

[0013] Preferably, the concentration of the Na2SO4 solution is 0.05-0.5M.

[0014] More preferably, the concentration of the Na2SO4 solution is 0.5 M. Among 0.05-0.5 M Na2SO4 electrolyte solutions, 0.5 M Na2SO4 electrolyte produces the highest amount of hydrogen peroxide.

[0015] Preferably, the voltage for electrocatalytic water oxidation to produce hydrogen peroxide is 1.8-3.6 V vs. RHE.

[0016] More preferably, the voltage of electrocatalytic water oxidation to produce hydrogen peroxide is 3.4 V vs. RHE.

[0017] When the applied voltage was 3.4 V vs. RHE, the yield of hydrogen peroxide could reach 79.35 μmol h -1, the Faradaic efficiency can reach 43.71% at 1.8V vs. RHE. This yield and Faradaic efficiency are the highest in existing non-bicarbonate electrolyte system research ( Figure 13 ), which are the highest Faradaic efficiency (18%) and the highest productivity (2.2794 μmol h -1 ) are 2.43 times and 34.81 times.

[0018] The present invention also provides the use of the above method for oxidizing water to produce hydrogen peroxide in a non-carbonate system in the degradation of antibiotic pollutants.

[0019] More preferably, the antibiotic contaminant includes norfloxacin. In principle, all antibiotics that can be degraded by hydrogen peroxide fall within the degradation scope of the present invention.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention discloses a method for producing hydrogen peroxide by oxidizing water in a non-carbonate system using a compressed basic copper carbonate anode. The method uses compressed basic copper carbonate as the anode and a Na2SO4 solution as the electrolyte, efficiently producing hydrogen peroxide in situ in the Na2SO4 electrolyte via a two-electron water oxidation pathway. The compressed basic copper carbonate has good stability, which facilitates the oxidation of water to produce hydrogen peroxide. Furthermore, the electrolyte solution of the non-carbonate system can effectively reduce the decomposition of hydrogen peroxide in the electrolyte solution, thereby achieving efficient water oxidation to produce hydrogen peroxide. The method of the present invention does not require pH adjustment or the presence of carbonates, providing a new research approach for the electrooxidation of hydrogen peroxide in water under neutral and acidic environments, and also provides a new approach for the degradation of antibiotic pollutants in the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The results are a comparison of the hydrogen peroxide production of a pressed basic copper carbonate anode, a smeared basic copper carbonate anode, and a graphite anode when catalyzing water oxidation to produce hydrogen peroxide in a Na2SO4 electrolyte solution for 120 minutes.

[0023] Figure 2 This is a comparison chart of the pressed basic copper carbonate anode and the smeared basic copper carbonate anode before and after use (use refers to the use of the pressed basic copper carbonate anode and the smeared basic copper carbonate anode to catalyze water oxidation to produce hydrogen peroxide in a Na2SO4 electrolyte solution);

[0024] Figure 3 The following are scanning electron microscope images of the compressed basic copper carbonate anode before and after use (use refers to the use of the compressed basic copper carbonate anode to catalyze water oxidation in a Na2SO4 electrolyte solution to produce hydrogen peroxide);

[0025] Figure 4The following are Fourier infrared absorption spectra of the compressed basic copper carbonate anode before and after use (use refers to the use of the compressed basic copper carbonate anode to catalyze water oxidation in a Na2SO4 electrolyte solution to produce hydrogen peroxide);

[0026] Figure 5 The X-ray diffraction patterns of the compressed basic copper carbonate anode before and after use (use refers to the use of the compressed basic copper carbonate anode to catalyze water oxidation in a Na2SO4 electrolyte solution to produce hydrogen peroxide);

[0027] Figure 6 This is the X-ray photoelectron absorption spectrum of the compressed basic copper carbonate anode before and after use (use refers to the use of the compressed basic copper carbonate anode to catalyze water oxidation in a Na2SO4 electrolyte solution to produce hydrogen peroxide);

[0028] Figure 7 The results are a comparison of the hydrogen peroxide production when compressed basic copper carbonate anode catalyzes water oxidation to produce hydrogen peroxide in Na2SO4 electrolyte solutions with different concentrations for 120 minutes.

[0029] Figure 8 The results are a comparison of the hydrogen peroxide production when the compressed basic copper carbonate anode catalyzes water oxidation in Na2SO4 electrolyte solution at different voltages for 120 minutes.

[0030] Figure 9 The results are the comparison of hydrogen peroxide production when compressed basic copper carbonate anode catalyzes water oxidation to produce hydrogen peroxide in Na2SO4 electrolyte solutions with different pH values for 120 minutes.

[0031] Figure 10 Comparison of AC impedance of compressed basic copper carbonate anode in Na2SO4 electrolyte solutions with different pH values;

[0032] Figure 11 The comparison results of the UV absorption peak of persulfate at 551nm under the DPD-POD detection system are shown in Figure 2.

[0033] Figure 12 The comparison of the removal of norfloxacin by in-situ generation of hydrogen peroxide using a pressed basic copper carbonate anode in Na2SO4 electrolyte solutions with different pH values was conducted.

[0034] Figure 13 The statistical results of the comparison of hydrogen peroxide production in different electrolyte systems are shown in Figure 2.

[0035] Figure 13 For other electrolyte systems, please refer to the following references:

[0036] 1.Xue,S.G.;Tang,L.;Tang,Y.K.;Li,C.X.;Li,M.L.;Zhou,J.J.;Chen,W.;Zhu,F.;Jiang,J.,Selective Electrocatalytic Water Oxidation to Produce H2O2Using aC,NCodoped TiO2Electrode in an Acidic Electrolyte.ACS Appl Mater Interfaces2020,12(4),4423-4431.

[0037] 2.Sebastian,A.;Remello,S.N.;Kuttassery,F.;Mathew,S.;Ohsaki,Y.;Tachibana,H.;Inoue,H.,Protolytic behavior of water-soluble zinc(II)porphyrinand the electrocatalytic two-electron water oxidation to form hydrogenperoxide.Journal of Photochemistry and Photobiology A:Chemistry 2020,400.

[0038] 3.Ohsaki,Y.;Thomas,A.;Kuttassery,F.;Mathew,S.;Remello,S.N.;Shimada,T.;Ishida,T.;Takagi,S.;Tachibana,H.;Inoue,H.,Two-electron oxidation of waterto form hydrogen peroxide initiated by one-electron oxidation of Tin(IV)-porphyrins.Journal of Photochemistry and Photobiology A:Chemistry 2020,401.

[0039] 4.Lai, Y.; Liu, DETAILED DESCRIPTION

[0040] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0041] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0042] Example 1 Preparation of Tableted Basic Copper Carbonate Block

[0043] (1) Cu2(OH)2CO3 powder and 60% by mass PTFE (polytetrafluoroethylene) aqueous solution were mixed and stirred at a ratio of 0.25 mL / g to form a slurry;

[0044] (2) transferring the slurry from step (1) to an oven at 70° C. and drying for 12 hours to obtain a PTFE-treated powder;

[0045] (3) Pour 2 g of the dry powder obtained in step (2) into a round cake-shaped mold and maintain it at a pressure of 10 kPa for 2 minutes to obtain a Cu2(OH)2CO3 cake-shaped block, i.e., a compressed basic copper carbonate block.

[0046] (4) As a comparison, the Cu2(OH)2CO3 powder of step (1) was not pretreated with PTFE and was directly introduced into a mold for tableting under the same conditions as step (3). However, it was found that it could not be pressed into a sheet-like block and remained in a powdery state.

[0047] (5) As a comparison, the PTFE adhesive in step (1) was replaced with PVDF, specifically: 0.1g PVDF + 1.5mL NMP + 1g Cu2(OH)2CO3 were mixed, and the resulting slurry was dried at 70°C for 12h and then pressed into sheets, but it was found that the directly formed blocks were not conductive.

[0048] (6) As a comparison, the ratio of Cu2(OH)2CO3 powder and PTFE solution in step (1) was adjusted to 0.05 mL / g, and step (2) was adjusted to drying at 70°C for 24 h, but it was found that the tablet-formed blocks were fragile.

[0049] (7) As a comparison, the ratio of Cu2(OH)2CO3 powder and PTFE solution in step (1) was adjusted to 2 mL / g, and step (2) was adjusted to drying at 70°C for 24 h, but it was found that the conductivity of the tablet-formed block was very poor.

[0050] (8) As a control, the slurry in step (1) was directly applied to a carbon paper substrate and allowed to stand at room temperature for more than 12 h to prepare a smeared basic copper carbonate block.

[0051] Example 2 Performance Verification of Compressed Basic Copper Carbonate Block Catalyzing Water Oxidation to Produce Hydrogen Peroxide

[0052] (1) Comparison of the electrocatalytic water oxidation performance of pressed block basic copper carbonate and smeared basic copper carbonate to produce hydrogen peroxide

[0053] The pressed basic copper carbonate block, the smeared basic copper carbonate block and graphite were placed as anodes in 50 mL of 0.5 M Na2SO4 electrolyte solution, and catalyzed water oxidation to produce hydrogen peroxide at a voltage of 3.4 V vs. RHE.

[0054] The results are as follows Figure 1 As shown in the figure, graphite cannot produce hydrogen peroxide in Na2SO4 electrolyte solution when used as anode. The hydrogen peroxide yield of coated basic copper carbonate in Na2SO4 electrolyte solution is far lower than that of pressed basic copper carbonate block anode. This is because a large amount of powder will fall off during the experiment (such as Figure 2 As shown), the hydrogen peroxide production did not increase in the later period.

[0055] At the same time, the scanning electron microscope, Fourier infrared absorption spectrum, X-ray diffraction and X-ray photoelectron absorption spectrum results of the compressed basic copper carbonate block prepared in Example 1 before and after catalyzing water oxidation to produce hydrogen peroxide are as follows: Figure 2 、 Figure 3 、 Figure 4 、 Figure 5As shown. Scanning electron microscopy results revealed that the compressed basic copper carbonate anode had a cohesive spherical structure, with no significant difference before and after the reaction. Fourier transform infrared absorption spectra of the electrode material showed no shift in the positions of the two spectral curves, and no new absorption waves appeared, indicating that the Cu2(OH)2CO3 anode did not generate new chemical bonds before and after use. X-ray diffraction patterns confirmed that the anode material's crystal structure was indeed basic copper carbonate Cu2(OH)2CO3 (PDF#41-1390) before and after the reaction. X-ray photoelectron absorption spectroscopy showed that the chemical environments of the O, C, and Cu elements in the electrode material remained essentially the same before and after use. These characterizations demonstrate that the surface electronic state and chemical elemental composition of the compressed basic copper carbonate anode material remain stable before and after electrocatalytic water oxidation to produce hydrogen peroxide.

[0056] (2) Comparison of the performance of compressed block basic copper carbonate in electrocatalytic water oxidation to produce hydrogen peroxide in Na2SO4 electrolyte solutions with different concentrations

[0057] The compressed basic copper carbonate block was placed as the anode in 0.05M, 0.1M and 0.5M Na2SO4 electrolyte solutions (50mL) respectively, and catalyzed water oxidation to produce hydrogen peroxide at a voltage of 3.4V vs. RHE. The results are shown in Figure 2. Figure 7 As shown, the most suitable electrolyte concentration is 0.5M.

[0058] (3) Comparison of the performance of compressed block basic copper carbonate electrocatalytic water oxidation to produce hydrogen peroxide at different voltages

[0059] The compressed basic copper carbonate block was placed as an independent anode in 50 mL of 0.5M Na2SO4 electrolyte solution and catalyzed water oxidation to produce hydrogen peroxide in the voltage range of 1.8-3.6 V vs. RHE. The results are shown in Figure 2. Figure 8 As shown, the hydrogen peroxide production rate is the highest when the voltage is 3.4 V vs. RHE.

[0060] (4) Comparison of the performance of compressed block basic copper carbonate anodes in electrocatalytic water oxidation to produce hydrogen peroxide in Na2SO4 electrolytes at different pH environments

[0061] The compressed basic copper carbonate block was used as the anode, and the pH of the Na2SO4 electrolyte solution was adjusted with H2SO4 and NaOH. The compressed basic copper carbonate block was then placed in 50mL of 0.5M Na2SO4 electrolyte solution with a pH of 4.17 and 50mL of 0.5M Na2SO4 electrolyte solution with a pH of 11.33, respectively. Water was oxidized to produce hydrogen peroxide at a voltage of 3.4V vs. RHE. 50mL of 0.5M Na2SO4 electrolyte solution without pH adjustment was used as a control. The results are shown in Figure 2. Figure 9As shown in Figure 2, as the pH increases, the production of hydrogen peroxide also increases. According to the AC impedance results of the basic copper carbonate pressed anode in acid and alkaline environments ( Figure 10 ) It can be seen that this is because in an alkaline electrolyte environment, the AC impedance of the anode in the system is smaller than that in an acidic environment.

[0062] Example 3 Comparison of Decomposition of Hydrogen Peroxide in Na2SO4 Solution and KHCO3 Solution

[0063] 10M H2O2 was diluted with water, 0.5M Na2SO4 solution, and 2M KHCO3 solution to produce 1mM hydrogen peroxide solutions in different solution systems, designated H2O2-H2O, H2O2-Na2SO4, and H2O2-KHCO3, respectively. The initial hydrogen peroxide concentration and the concentration after 24 hours at room temperature were then determined using the DPD-POD method. The results, shown in Table 1, demonstrate that the autolysis of hydrogen peroxide in Na2SO4 solution is significantly less than that in KHCO3 solution, demonstrating the superiority of Na2SO4 solution as an electrolyte for hydrogen peroxide production.

[0064] Table 1 Comparative results of decomposition of hydrogen peroxide in Na2SO4 solution and KHCO3 solution

[0065]

[0066] Example 4: Verification of the production of hydrogen peroxide by catalytic water oxidation using Na2SO4 electrolyte using pressed basic copper carbonate

[0067] Given the possibility of the coexistence of sodium sulfate and hydrogen peroxide in the process of producing hydrogen peroxide by catalyzing water oxidation with a pressed basic copper carbonate anode using a Na2SO4 electrolyte, it is necessary to prove that the product is hydrogen peroxide and not other products. The specific proof experimental process is as follows:

[0068] (1) K2S2O8-H2O: A series of K2S2O8 solutions with a concentration gradient (0, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 10, 100 mM) were prepared by dilution with water, and the UV absorbance of hydrogen peroxide was measured using the DPD-POD method;

[0069] (2) K2S2O8-0.8 mM H2O2 solution: A series of K2S2O8 solutions with a concentration gradient (0, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 10, 100 mM) were prepared by diluting the solution with 0.8 mM H2O2, and then the UV absorbance of hydrogen peroxide was measured by the DPD-POD method;

[0070] (3) KHSO5-H2O: A series of KHSO5 solutions with a concentration gradient (0, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 10, 100 mM) were prepared by dilution with water, and the UV absorbance of hydrogen peroxide was measured using the DPD-POD method;

[0071] (4) KHSO5-0.8mM H2O2: A series of KHSO5 solutions with a concentration gradient (0, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 10, 100mM) were prepared by diluting 0.8mM H2O2 solution, and then the UV absorbance of hydrogen peroxide was measured by the DPD-POD method;

[0072] The results are as follows Figure 11 As shown, in Figure 11 a reflects the absorbance of K2S2O8 in water at 551 nm. No peak is observed at 551 nm in the spectra of K2S2O8 concentrations of 0, 0.1, 0.2, 0.4, 0.6, 0.8, and 1 mM. Only when the concentration is increased to 10 mM does an observable peak appear at 551 nm. Because the hydrogen peroxide concentration in this experiment was limited (persulfate is formed by the reaction of hydrogen peroxide and sulfate, and the reactant concentration never exceeds 1 mM), persulfate production is unlikely to exceed 1 mM, as the hydrogen peroxide concentration in this experiment barely reached 1 mM. Furthermore, the absorbance of the samples measured at different time points during the experiment also increases normally.

[0073] Figure 11 b shows the peak of the ultraviolet absorption spectrum of K2S2O8 in the presence of hydrogen peroxide. It can be seen that the absorbance of K2S2O8 in the presence of hydrogen peroxide is more obvious than in water. Among them, 0mM is the absorbance of 0.8mM hydrogen peroxide. As the concentration of K2S2O8 increases, the increase in absorbance in the concentration range of 0-10mM is not obvious. When the concentration of K2S2O8 in water or hydrogen peroxide is 100mM, there is no peak at 551nm. Therefore, if K2S2O8 is produced in this experiment, the increase in absorbance with increasing concentration is very insignificant, but this experiment monitored a significant increase in the absorbance of the sample at 551nm at different time points ( Figure 11 e). Therefore, the main product is not K2S2O8.

[0074] Figure 11 Figure c reflects the absorbance of KHSO₅ in water at 551 nm, which is similar to the absorbance regulation of K₂S₂O₅. When the concentration of K₂S₂O₅ is below 1 mM, there is no distinct absorption peak at 551 nm, but the absorbance at 10 mM and 100 mM increases abruptly. However, the absorbance of K₂S₂O₅ at 10 mM and 100 mM is much lower than that of K₂S₂O₅ in water.

[0075] Figure 11 d reflects the absorbance of KHSO5 at 551nm at different concentrations in the presence of hydrogen peroxide. The absorbance of 0mM KHSO5, that is, pure 0.8mM hydrogen peroxide, has a UV absorption peak at 551nm. Interestingly, the absorbance of the curves of other concentrations at 551nm is lower than that of the 0mM curve, which shows that the presence of KHSO5 will affect the absorbance of hydrogen peroxide at 551nm. Therefore, if KHSO5 is formed in this experiment, it will cause a significant decrease in absorbance. However, the absorbance of the sample detected in this experiment is a normal increase ( Figure 11 e) Although KHSO₅ ...

[0076] In summary, the product of basic copper carbonate tablets in Na2SO4 electrolyte is indeed hydrogen peroxide rather than persulfate.

[0077] Example 5: In-situ generation of hydrogen peroxide by compressed block basic copper carbonate independent anode in Na2SO4 electrolyte solution at different pH environments to remove norfloxacin

[0078] A technology for producing hydrogen peroxide by oxidizing water in a neutral, non-carbonate electrolyte Na2SO4 solution using a compressed basic copper carbonate anode. The synthesis of the catalyst comprises the following steps:

[0079] (1) Cu2(OH)2CO3 powder and 60% PTFE solution were mixed and stirred at a ratio of 0.25 mL / g to form a slurry;

[0080] (2) Transfer the slurry from step (1) to an oven at 70°C and dry for 12 hours to obtain a PTFE-treated powder;

[0081] (3) Pour 2 g of the dry powder obtained in step (2) into a mold and maintain it at a pressure of 10 kPa for 2 min to obtain a Cu2(OH)2CO3 cake-shaped block;

[0082] The compressed basic copper carbonate block was used as the anode, and the pH of the Na2SO4 electrolyte solution was adjusted with H2SO4 and NaOH. The compressed basic copper carbonate block was then placed in 50 mL of 0.5 M Na2SO4 electrolyte solution with a pH of 4.17 and 50 mL of 0.5 M Na2SO4 electrolyte solution with a pH of 11.33, respectively, to catalyze water oxidation to produce hydrogen peroxide at a voltage of 3.4 V vs. RHE.

[0083] The compressed basic copper carbonate block was used as an independent anode, and the pH of the Na2SO4 electrolyte solution was adjusted with H2SO4 and NaOH. At the same time, norfloxacin with an initial concentration of 10 ppm was added to the electrolyte solution. The compressed basic copper carbonate block was then placed in 50 mL of 0.5 M Na2SO4 electrolyte solution with a pH of 4.17 and 50 mL of 0.5 M Na2SO4 electrolyte solution with a pH of 11.33, respectively. 50 mL of 0.5 M Na2SO4 electrolyte solution without pH adjustment was used as a control. Finally, the catalytic effect of in situ production of hydrogen peroxide from water to remove norfloxacin was observed at a voltage of 3.4 V vs. RHE.

[0084] The results are as follows Figure 12 As shown in the figures, the removal effect of norfloxacin in acidic (100%) and neutral (57.97%) environments is better than that in alkaline (26.42%) environments, which also shows the superiority of the compressed basic copper carbonate block of the present invention in environmental applications for in-situ generation of hydrogen peroxide under acidic or neutral conditions.

[0085] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system, characterized in that: Using compressed basic copper carbonate as the anode and Na2SO4 solution as the electrolyte, water is electrocatalyzed to produce hydrogen peroxide. The preparation method of the tableted basic copper carbonate comprises the following steps: mixing Cu2(OH)2CO3 and PTFE to form a slurry, drying the slurry, adding the slurry into a mold, and performing tableting to obtain the tableted copper carbonate.

2. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 1, characterized in that: The PTFE is a 60% PTFE solution, and the material-liquid ratio of Cu2(OH)2CO3 to PTFE solution is 0.05-2 mL / g.

3. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 2, characterized in that: The material-liquid ratio of Cu2(OH)2CO3 and PTFE solution is 0.25mL / g.

4. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 1, characterized in that: The concentration of Na2SO4 solution is 0.05-0.5 M.

5. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 4, characterized in that: The concentration of Na2SO4 solution is 0.5 M.

6. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 1, characterized in that: The voltage for electrocatalytic water oxidation to produce hydrogen peroxide is 1.8-3.6 V vs. RHE.

7. A method for producing hydrogen peroxide by oxidizing water in a non-carbonate system according to claim 6, characterized in that: The voltage of electrocatalytic water oxidation to produce hydrogen peroxide is 3.4 V vs. RHE.

8. Use of the method for oxidizing water to produce hydrogen peroxide in a non-carbonate system according to any one of claims 1 to 7 in degrading antibiotic pollutants.

9. The use according to claim 8, characterized in that The antibiotic contaminants include norfloxacin.

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