3D electro-catalytic pms coupling system and application thereof

Abstract

The application relates to a 3D electrocatalytic PMS coupling system and application thereof. The system comprises an anode, a cathode, an electrolyte, a persulfate and a Cu@CA catalyst; wherein the anode is Ti4O7, the Cu@CA catalyst is prepared by the following steps: uniformly mixing a glucose solution and a CuCl2 solution, degassing through a freeze-vacuum-thaw cycle, then carrying out hydrothermal synthesis on the mixed solution, the temperature is 170-200 DEG C, the time is 300-500 min, after the reaction is completed, the reaction liquid is cooled, centrifuged and filtered to obtain a precipitate; the precipitate is washed, then dried and ground to obtain a precursor powder; the precursor powder is annealed for 1-3 h to obtain the Cu@CA catalyst. The coupling system solves the problem that the Ti4O7 has poor degradation effect on PPCPS, and meanwhile, the research opens up a new way for rational regulation of metal active sites and oxygen and water adsorption reaction.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic degradation of pollutants technology, specifically relating to a 3D electrocatalytic PMS coupling system and its application. Background Technology

[0002] Pharmaceuticals and personal care products (PPCPs) are a representative class of emerging pollutants, widely used globally. They primarily include various pharmaceuticals such as antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), antiviral drugs, beta-blockers, lipid regulators, anticonvulsants, and X-ray contrast agents, as well as personal care products. PPCPs are prevalent in aquatic environments, potentially causing adverse effects on aquatic organisms and posing a potential threat to human health; the resulting environmental risks are receiving increasing attention.

[0003] Electrochemical water treatment technology is characterized by its short-range, green, efficient, and intelligent nature, and it holds great potential for the deep treatment of new pollutants in water, making it a current research hotspot in environmental engineering. Ti4O7 electrode materials are currently popular due to their low cost and reliability; however, the accumulation of pollutants or intermediate products on the electrode surface leads to decreased activity; its degradation effect on specific pollutants (such as PPCPs) is poor; and compared to some highly catalytically active materials (such as boron-doped diamond electrodes BDD, SnO2, RuO2, IrO2, etc.), Ti4O7 has limited ability to generate reactive oxygen species (ROS) such as hydroxyl radicals (·OH). Summary of the Invention

[0004] The primary objective of this invention is to provide a 3D electrocatalytic PMS (persulfate) coupling system composed of a three-dimensional metal particle electrode Cu@CA and a Ti4O7 electrode, which solves the problem of poor degradation effect of Ti4O7 on PPCPS. At the same time, this study opens up a new way for rationally regulating the adsorption reaction of metal active sites with oxygen and water, and provides guidance for the design of highly efficient electrocatalysts.

[0005] Another object of the present invention is to provide the application of the above-mentioned 3D electrocatalytic PMS coupling system.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A 3D electrocatalytic PMS coupling system includes an anode, a cathode, an electrolyte, a persulfate, and a Cu@CA catalyst; wherein the anode is Ti4O7, and the Cu@CA catalyst is prepared by the following steps:

[0008] S1. Mix glucose solution and copper salt solution evenly, degas by freezing-vacuuming-thawing cycle, and then perform hydrothermal synthesis on the mixed solution at a temperature of 170~200 ℃ for 300~500 min. After the reaction is completed, cool the reaction solution, centrifuge and filter to obtain black precipitate.

[0009] S2. Wash the precipitate, then dry and grind it to obtain precursor powder; anneal the precursor powder at 300~500℃ for 1-3 h to obtain Cu@CA catalyst.

[0010] Preferably, the concentration of the Cu@CA catalyst in the 3D electrocatalytic PMS coupling system is 0.1~0.3 g / L, more preferably 0.2 g / L.

[0011] Preferably, the cathode is pure titanium.

[0012] Preferably, the electrolyte is a Na2SO4 solution with a concentration of 50~100 mmol / L, more preferably 100 mmol / L.

[0013] Preferably, the concentration of persulfate in the system is 2 mmol / L.

[0014] Preferably, the operating conditions of the 3D electrocatalytic PMS coupling system are: current density 5-30 mA / cm². 2 pH value 5~9; more preferred operating conditions are: current density 20 mA / cm² 2 pH value 5.94.

[0015] Preferably, in S1, the conditions for the freezing-vacuuming-thawing cycle degassing are: a temperature of -10 °C and a time of 24 h.

[0016] Preferably, in S1, the copper salt is CuCl2, and the mass ratio of glucose to CuCl2 is 5.55:8.

[0017] Preferably, in step S1, the hydrothermal synthesis temperature is 180 °C and the time is 300 min.

[0018] Preferably, in step S2, the annealing temperature is 400 °C and the annealing time is 1 h.

[0019] Preferably, in step S2, the annealing environment is an air atmosphere or an inert gas atmosphere.

[0020] The 3D electrocatalytic PMS coupling system described in this invention can be used to degrade propranolol.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0022] 1. This invention prepares a 3D electrocatalytic PMS coupling system composed of three-dimensional metal particle electrode material Cu@CA and Ti4O7 electrode using a low-cost and reliable method, thereby achieving efficient degradation of target pollutants.

[0023] 2. In the 3D electrocatalytic PMS coupling system of the present invention, the three-dimensional metal particle electrode material Cu@CA can be reused and the stability of the system is improved. Attached Figure Description

[0024] Figure 1 Images (a), (b), and (c) are SEM images of the Cu@CA catalyst prepared by annealing at 300 °C, 400 °C, and 500 °C in Example 1, respectively. Figure 1 (d) in the figure is the TEM and EDS image of the Cu@CA catalyst prepared by annealing at 400 °C in Example 1;

[0025] Figure 2 The above are XPS spectra of the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, where (a) is the total XPS spectrum, (b) is the XPS spectrum of C, (c) is the XPS spectrum of O, (d) is the XPS spectrum of Cl, and (e) is the XPS spectrum of Cu.

[0026] Figure 3 This figure shows the degradation effect of Cu@CA catalyst prepared by annealing at 400 °C in different reaction systems on propranolol. In the figure, PMS represents the persulfate degradation system alone, Cu@CA represents the Cu@CA catalyst degradation system alone, PMS / Cu@CA represents the co-degradation system of persulfate and Cu@CA catalyst, ECO represents the Ti4O7 anode electrocatalytic degradation system alone, ECO / Cu@CA represents the Ti4O7 anode and Cu@CA catalyst co-degradation system, and ECO / PMS / Cu@CA represents the Ti4O7 anode, persulfate and Cu@CA catalyst co-degradation system (i.e., 3D electrocatalytic PMS coupling system).

[0027] Figure 4 The effects of the 3D electrocatalytic PMS coupling system (a) constructed with Cu@CA catalyst prepared by annealing at 400 °C in Example 1 and the 3D electrocatalytic PMS coupling system (b) constructed with Cu@CA catalyst prepared in Example 2 on the degradation of propranolol are shown.

[0028] Figure 5 The effects of the 3D electrocatalytic PMS coupling system (a) constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 and the coupling system (b) constructed from the catalyst prepared in Comparative Example 1 on the degradation of propranolol are shown.

[0029] Figure 6 The effect of the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, the Fe@CA catalyst prepared in Comparative Example 2, and the Co@CA catalyst prepared in Comparative Example 3 on the degradation of propranolol by a 3D electrocatalytic PMS coupling system.

[0030] Figure 7 This describes the effect of the 3D electrocatalytic PMS coupling system constructed from Cu@CA catalysts prepared at different annealing temperatures in Example 1 on the degradation of propranolol;

[0031] Figure 8 The effects of 3D electrocatalytic PMS coupling systems constructed with Cu@CA catalysts prepared with different copper salts on the degradation of propranolol are shown. CuCl2 represents the 3D electrocatalytic PMS coupling system constructed with Cu@CA catalyst prepared by annealing at 400 °C in Example 1, Cu(NO3)2 represents the 3D electrocatalytic PMS coupling system constructed with Cu@CA-N catalyst prepared in Comparative Example 4, and CuAC2 represents the 3D electrocatalytic PMS coupling system constructed with Cu@CA catalyst-AC prepared in Comparative Example 5.

[0032] Figure 9 This describes the effect of the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 on the degradation of propranolol at different pH values ​​in a 3D electrocatalytic PMS coupling system.

[0033] Figure 10 This is an example of the effect of different current densities on the degradation of propranolol on a 3D electrocatalytic PMS coupling system constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1.

[0034] Figure 11 The effect of different amounts of Cu@CA catalyst prepared by annealing at 400 °C in Example 1 on the degradation of propranolol is shown in the 3D electrocatalytic PMS coupling system constructed by the Cu@CA catalyst in Example 1 with different amounts of catalyst on the degradation of propranolol.

[0035] Figure 12 These are ESR data of the 3D electrocatalytic PMS coupling system constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 at different degradation times;

[0036] Figure 13 The figures show the quenching experiment (a) and the corresponding quenching reaction rate (b) of the 3D electrocatalytic PMS coupling system constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1; blank and control are blank control groups; TBA is the quenching experiment with tert-butanol as the quencher; MeOH is the quenching experiment with methanol as the quencher.

[0037] Figure 14This is a probe experiment of the 3D electrocatalytic PMS coupling system (ECO / PMS / Cu@CA) constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, and the oxidation probe of the Ti4O7 anodic electrocatalytic degradation system (ECO).

[0038] Figure 15 The values ​​represent the generation and exposure of hydroxyl and sulfate groups in the 3D electrocatalytic PMS coupling system (ECO / PMS / Cu@CA) constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, and in the simple Ti4O7 anodic electrocatalytic degradation system (ECO).

[0039] Figure 16 The steady-state concentrations of hydroxyl and sulfate ions are found in the 3D electrocatalytic PMS coupling system (ECO / PMS / Cu@CA) constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, and in the simple Ti4O7 anodic electrocatalytic degradation system (ECO).

[0040] Figure 17 This is the free radical contribution of the 3D electrocatalytic PMS coupling system constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 under quenching and probe experiments.

[0041] Figure 18 The 3D electrocatalytic PMS coupled system constructed from the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 underwent five degradation cycles. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.

[0043] Example 1:

[0044] S1. Dissolve 5.55 g of glucose and 8 g of CuCl2 in deionized water (20 mL and 30 mL respectively) under magnetic stirring to obtain solutions A and B respectively.

[0045] S2. Add solution A to solution B, sonicate to mix them completely, degas by freezing-vacuuming-thawing cycle (minus 10 °C, 24 h), and then transfer the mixed solution to a hydrothermal reactor.

[0046] S3. The mixed solution is subjected to hydrothermal synthesis (180 °C, 400 min) to generate a black precipitate.

[0047] S4. After cooling, the precipitate is centrifuged, filtered, washed, and then dried. The precipitate is ground using a mortar and pestle, and the ground powder is mixed by shaking to obtain precursor powder. Three groups of precursor powders are taken and annealed in an air atmosphere in a tube furnace at 300, 400, and 500°C for 1 h (heating rate of 1 °C / min) to synthesize Cu@CA catalysts annealed at different temperatures.

[0048] The SEM image of the Cu@CA catalyst prepared above is shown below. Figure 1 As shown, Figure 1 As shown in (a), (b), and (c), different annealing temperatures do not significantly affect the morphology of Cu@CA, and their overall morphology is spherical. Figure 1 (d) in the figure shows the TEM and EDS of the Cu@CA catalyst prepared by annealing at 400 °C. The figure shows the internal hollowing of Cu@CA.

[0049] XPS spectra of Cu@CA prepared by annealing at 400 °C in Example 1 are as follows: Figure 2 As shown. Figure 2 As shown in (a), there were no significant changes in all the characteristic diffraction peaks of Cu@CA before and after the reaction, indicating that Cu@CA was relatively stable before and after the reaction. Figure 2 (b) and (d) in the figure indicate that C and Cl elements are relatively stable before and after the reaction. Figure 2 (c) in the text indicates that O VAC The content increased from 45.27% before the reaction to 67.51%, which may provide evidence for the increase in oxygen vacancy concentration. Figure 2 (e) in the figure indicates that Cu after the reaction 2+ The content has been significantly increased.

[0050] Example 2:

[0051] S1~S3 are the same as steps S1~S3 in Example 1;

[0052] S4. After cooling, the precipitate is centrifuged, filtered, washed, and then dried. The precipitate is ground using a mortar and pestle, and the ground powder is mixed by shaking to obtain precursor powder. The precursor powder is annealed in a tube furnace under a nitrogen atmosphere at 400 °C for 1 h (heating rate 1 °C / min) to obtain Cu@CA catalyst.

[0053] Comparative Example 1:

[0054] S1. Dissolve 5.55 g of glucose and 8 g of CuCl2 in deionized water (20 mL and 30 mL respectively) under magnetic stirring to obtain solutions A and B respectively.

[0055] S2. Add solution A to solution B, sonicate to mix them completely and evenly, and then transfer the mixed solution to a hydrothermal reactor.

[0056] S3. The mixed solution is subjected to hydrothermal synthesis (180 °C, 400 min) to generate a precipitate.

[0057] S4. After cooling, the precipitate is centrifuged, filtered, washed, and then dried. The precipitate is ground using a mortar and pestle, and the ground powder is mixed by shaking to obtain precursor powder. The precursor powder is annealed in a tube furnace under a nitrogen atmosphere at 400 °C for 1 h (heating rate 1 °C / min) to obtain the catalyst.

[0058] Comparative Example 2:

[0059] S1. Dissolve 5.55 g of glucose and 8 g of FeCl2 in deionized water (20 mL and 30 mL respectively) under magnetic stirring to obtain solutions A and B respectively.

[0060] S2. Add solution A to solution B, sonicate to mix them completely, degas by freezing-vacuuming-thawing cycle (minus 10 °C, 24 h), and then transfer the mixed solution to a hydrothermal reactor.

[0061] S3. The mixed solution is subjected to hydrothermal synthesis (180 °C, 400 min) to generate a precipitate.

[0062] S4. After cooling, the precipitate was centrifuged, filtered, washed, and then dried. The precipitate was ground in a mortar and pestle, and the ground powder was mixed by shaking to obtain precursor powder. The precursor powder was annealed in an air atmosphere in a tube furnace at 400 °C for 1 h (heating rate 1 °C / min) to synthesize Fe@CA catalyst.

[0063] Comparative Example 3:

[0064] S1. Dissolve 5.55 g of glucose and 8 g of CoCl2 in deionized water (20 mL and 30 mL respectively) under magnetic stirring to obtain solutions A and B respectively.

[0065] S2. Add solution A to solution B, sonicate to mix them completely, degas by freezing-vacuuming-thawing cycle (minus 10 °C, 24 h), and then transfer the mixed solution to a hydrothermal reactor.

[0066] S3. The mixed solution is subjected to hydrothermal synthesis (180 °C, 400 min) to generate a precipitate.

[0067] S4. After cooling, the precipitate was centrifuged, filtered, washed, and then dried. The precipitate was ground in a mortar and pestle, and the ground powder was mixed by shaking to obtain precursor powder. The precursor powder was annealed in an air atmosphere in a tube furnace at 400 °C for 1 h (heating rate 1 °C / min) to synthesize the Co@CA catalyst.

[0068] Comparative Example 4

[0069] Following the method of Example 1, except that CuCl2 was replaced with Cu(NO3)2 and the annealing temperature was fixed at 400 °C, the other conditions remained unchanged to prepare Cu@CA catalyst-N.

[0070] Comparative Example 5

[0071] Following the method of Example 1, except that CuCl2 was replaced with CuAC2 and the annealing temperature was fixed at 400 °C, the other conditions remained unchanged to prepare Cu@CA catalyst-AC.

[0072] Degradation experiment:

[0073] 1. Constructing different degradation systems to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell. A pure titanium mesh with a surface polished with 400cc sandpaper was used as the cathode. A two-electrode system with a constant current density of 20 mA / cm² was employed. 2 The magnetic stirring speed was 750 r / min, and the oxidation was carried out at room temperature for 30 min at pH 5.94. Other conditions were as follows:

[0074] 1) Persulfate degradation system alone (PMS), without an anode, only persulfate as catalyst 2 mM; 2) Cu@CA catalyst degradation system alone (Cu@CA), without an anode, with Cu@CA catalyst (0.2 g / L) prepared by annealing at 400 °C in Example 1 added, without persulfate; 3) Persulfate and Cu@CA catalyst co-degradation system (PMS / Cu@CA), without an anode, with Cu@CA catalyst (0.2 g / L) prepared by annealing at 400 °C in Example 1 added and persulfate (2 mM); 4) Ti4O7 anode electrocatalytic degradation system alone (ECO), Ti4O7 as anode, no catalyst added; 5) Ti4O7 anode and Cu@CA catalyst co-degradation system (ECO / Cu@CA), Ti4O7 as anode, with Cu@CA catalyst (0.2 g / L) prepared by annealing at 400 °C in Example 1 added (0.2 g / L). 6) Ti4O7 anode, persulfate and Cu@CA catalyst co-degradation system (ECO / PMS / Cu@CA), with Ti4O7 as the anode, and Cu@CA catalyst (0.2 g / L) prepared by annealing at 400 °C in Example 1 and persulfate (2 mM) added. The results are as follows: Figure 3 As shown in the figure, it can be seen that the degradation capacity of the 3D electrocatalytic PMS coupling system provided by the present invention is superior when compared with different processes.

[0075] 2. Coupled systems were constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, the Cu@CA catalyst prepared in Example 2, and the catalysts prepared in Comparative Examples 1-3, respectively, to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size with a surface polished with 400 cc sandpaper as the cathode. 0.2 g / L of catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a dual-electrode system. 2 The magnetic stirring speed was 750 r / min, and the oxidation was carried out at room temperature for 30 min at pH 5.94.

[0076] Figure 4 The effects of the 3D electrocatalytic PMS coupling system constructed with the Cu@CA catalyst prepared in Example 1 by annealing at 400 °C (a) and the 3D electrocatalytic PMS coupling system constructed with the Cu@CA catalyst prepared in Example 2 (b) on the degradation of propranolol are shown. Figure 4 This indicates that the gaseous atmosphere has no direct impact on the material properties.

[0077] Figure 5The effects of the 3D electrocatalytic PMS coupling system (b) constructed from the Cu@CA catalyst prepared in Example 1 by annealing at 400 °C and the coupling system (a) constructed from the catalyst prepared in Comparative Example 1 on the degradation of propranolol are shown. Figure 5 This indicates that vacuum freezing is a necessary factor.

[0078] Figure 6 The effect of the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, the Fe@CA catalyst prepared in Comparative Example 2, and the Co@CA catalyst prepared in Comparative Example 3 on the degradation of propranolol by a 3D electrocatalytic PMS coupling system. Figure 6 This indicates that the system with Cu@CA catalyst exhibits superior degradation performance of propranolol.

[0079] 3. Coupled systems were constructed using the Cu@CA catalysts prepared in Example 1 at different annealing temperatures to degrade propranolol. The experimental conditions were the same as in degradation experiment 2, and the results are as follows: Figure 7 As shown. From Figure 7 As can be seen, under the same conditions, the Cu@CA catalyst prepared by annealing at 400 °C has the best effect on the degradation of propranolol.

[0080] 4. Coupled systems were constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1, and the catalysts prepared in Comparative Examples 4 and 5, respectively, to degrade propranolol. The experimental conditions were the same as in degradation experiment 2, and the results are as follows: Figure 8 As shown. From Figure 8 As can be seen, under the same conditions, the Cu@CA catalyst prepared by CuCl2 has the best effect on the degradation of propranolol.

[0081] 5. A 3D electrocatalytic PMS coupling system was constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size with a surface polished with 400cc sandpaper as the cathode. 0.2 g / L of Cu@CA catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a dual-electrode system. 2 The magnetic stirring speed was 750 r / min, and oxidation was carried out at room temperature for 30 min. Four experimental groups were set up with pH values ​​of 2.76, 5.94, 9.03, and 11. The results are as follows: Figure 9 As shown.

[0082] 6. A 3D electrocatalytic PMS coupling system was constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size with a surface polished with 400cc sandpaper as the cathode. 0.2 g / L of Cu@CA catalyst and persulfate (2 mM) were added. A two-electrode system was used with a constant current density and a magnetic stirring rate of 750 r / min. Oxidation was carried out at room temperature for 30 min at pH 5.94. Four sets of experiments were set up with current densities of 5, 10, 20, and 30 mA / cm². 2 The result is as follows Figure 10 As shown.

[0083] 7. A 3D electrocatalytic PMS coupling system was constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size with a surface polished with 400cc sandpaper as the cathode. Cu@CA catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a dual-electrode system. 2 The magnetic stirring speed was 750 r / min, and oxidation was carried out at room temperature for 30 min at pH 5.94. Four experimental groups were set up, with Cu@CA catalyst addition amounts of 0, 0.1, 0.2, and 0.3 g / L, respectively. The results are as follows: Figure 11 As shown.

[0084] 8. A coupled system was constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1 to degrade propranolol. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size with a surface polished with 400cc sandpaper as the cathode. 0.2 g / L of catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a dual-electrode system. 2 The magnetic stirring speed was 750 r / min, and oxidation was carried out at room temperature for 30 min at pH 5.94. ESR data were measured at degradation times of 0, 10, 20, and 30 min, and the results are as follows: Figure 12 As shown. From Figure 12 It can be seen that the 3D electrocatalytic PMS coupling system has obvious hydroxyl and sulfate signals.

[0085] 9. Figure 13 The images show the quenching experiment (a) and the corresponding quenching reaction rate (b) of the 3D electrocatalytic PMS coupling system constructed using the Cu@CA catalyst prepared by annealing at 400 °C in Example 1. Quenching experiment conditions: 100 mL of 10 mg / L propranolol aqueous solution was added, along with 500 mM tert-butanol or methanol, and 1.4204 g of Na2SO4 electrolyte. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size, polished with 400cc sandpaper, as the cathode. 0.2 g / L of catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a dual-electrode system. 2 The magnetic stirring speed was 750 r / min, and oxidation was carried out at room temperature for 30 min at pH 5.94. A blank control group without tert-butanol or methanol was also included. Figure 13 The quenching experiment can preliminarily verify that the hydroxyl radical is the main free radical in the reaction.

[0086] 10. To avoid the limitations of quenching, oxalic acid (OA), nitrobenzene (NB), and atrazine (ATZ) were used as free radical probes for probe experiments. Experimental conditions: Three groups of 100 mL ultrapure water were measured, and OA, NB, and ATZ probes were added respectively (probe concentrations: OA = 1 mM, ATZ = 10 µM, NB = 10 µM). 1.4204 g of Na2SO4 electrolyte was added. The probes were mixed with sodium sulfate and poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size, polished with 400cc sandpaper, as the cathode. 0.2 g / L Cu@CA catalyst and persulfate (2 mM) were added. A two-electrode system with a constant current density of 20 mA / cm² was used. 2 The magnetic stirring speed was 750 r / min, and oxidation was carried out at room temperature for 30 min at pH 5.94. A simple Ti4O7 anodic electrocatalytic degradation system (ECO) was also set up as a control group. The results are as follows: Figure 14-17 As shown.

[0087] according to Figure 14 The first-order dynamic constants in the equation are used for calculation. Figure 15 The steady-state concentrations of hydroxyl radicals and sulfate radicals in the 3D electrocatalytic PMS coupling system composed of a three-dimensional metal particle electrode Cu@CA and a Ti4O7 electrode were found to be 1.18E-12M and 5.96E-13M, respectively, which are much higher than those in the Ti4O7 system alone. Figure 16 ).

[0088] Figure 17 The data from the quenching experiment and the probe experiment were combined, ultimately confirming the dominant position of hydroxyl radicals.

[0089] 11. Cyclic degradation experiment. Experimental conditions: 100 mL of 10 mg / L propranolol aqueous solution was measured, and 1.4204 g of Na2SO4 electrolyte was added. After mixing, the mixture was poured into an electrolytic cell with Ti4O7 as the anode and a pure titanium mesh of the same size, polished with 400 cc sandpaper, as the cathode. 0.2 g / L of catalyst and persulfate (2 mM) were added. A constant current density of 20 mA / cm² was used in a two-electrode system. 2 The magnetic stirring speed was 750 r / min, and the oxidation was carried out at room temperature for 30 min at pH 5.94.

[0090] Figure 18 This refers to five degradation cycles of a 3D electrocatalytic PMS coupled system constructed from the Cu@CA catalyst prepared in Example 1 by annealing at 400 °C. Figure 18 As shown, the degradation rate of the 3D electrocatalytic PMS coupling system did not change significantly after five consecutive degradation cycles.

[0091] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A 3D electrocatalytic PMS coupling system, characterized in that, It includes an anode, cathode, electrolyte, persulfate, and Cu@CA catalyst; The anode is Ti4O7, and the Cu@CA catalyst is prepared by the following steps: S1. Mix glucose solution and copper salt solution evenly, degas by freezing-vacuuming-thawing cycle, and then perform hydrothermal synthesis of the mixed solution at a temperature of 170~200 ℃ for 300~500 min. After the reaction is completed, cool the reaction solution, centrifuge and filter to obtain the precipitate. S2. Wash the precipitate, then dry and grind it to obtain precursor powder; anneal the precursor powder at 300~500 ℃ for 1-3 h to obtain Cu@CA catalyst.

2. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, The concentration of the Cu@CA catalyst in the 3D electrocatalytic PMS coupling system is 0.1~0.3 g / L.

3. The 3D electrocatalytic PMS coupling system according to claim 2, characterized in that, The concentration of the Cu@CA catalyst in the 3D electrocatalytic PMS coupling system is 0.2 g / L.

4. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, The electrolyte is a Na2SO4 solution with a concentration of 50~100 mmol / L; The concentration of persulfate in the system is 2 mmol / L; The operating conditions of the 3D electrocatalytic PMS coupling system are: current density 5-30 mA / cm². 2 pH value 5~9.

5. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, In S1, the conditions for the freezing-vacuuming-thawing cycle degassing are: a temperature of -10 °C and a time of 24 h.

6. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, In S1, the copper salt is CuCl2, and the mass ratio of glucose to CuCl2 is 5.55:

8.

7. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, In S1, the hydrothermal synthesis temperature is 180 ℃ and the time is 300 min.

8. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, In step S2, the annealing temperature is 400 °C and the annealing time is 1 h.

9. The 3D electrocatalytic PMS coupling system according to claim 1, characterized in that, In step S2, the annealing environment is an air atmosphere or an inert gas atmosphere.

10. The application of the 3D electrocatalytic PMS coupling system according to any one of claims 1 to 9 in the degradation of propranolol.

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