A non-metallic doped titanium-based metal monatomic electrode for decomplexing heavy metals in complex state and a preparation method and application thereof

Abstract

The application belongs to the field of heavy metal complex wastewater treatment, and particularly relates to a non-metal doped titanium-based metal monatomic electrode for dissociating complex heavy metals, a preparation method and application thereof, which comprises a titanium substrate, and non-metal atoms and metal monatomic atoms respectively loaded on the surface of the titanium substrate; the non-metal atoms are selected from one or more of phosphorus, boron and sulfur; and the metal monatomic atoms are selected from one or both of iron and cobalt. Compared with the prior art, the application solves the problems of poor activity and insufficient stability of the electrochemical anode material in breaking the complex heavy metals in the prior art. The strong bonding interaction between the inherent oxidation layer on the surface of the titanium-based material and the metal monatomic sites is utilized to fix the metal monatomic atoms on the material surface, and the non-metal is introduced to control the electronic structure of the metal, so as to improve the stability and breaking performance of the metal sites.

Description

Technical Field

[0001] This invention belongs to the field of heavy metal complex wastewater treatment, specifically relating to a non-metallic doped titanium-based single-atom electrode for dissolving complexed heavy metals, its preparation method, and its application. Background Technology

[0002] Industries such as metal smelting, electrolysis, electroplating, and chemical cleaning discharge millions of tons of heavy metal wastewater annually. Heavy metals in this wastewater typically exist in stable complexed forms (e.g., Ni(II)-EDTA), making deep removal difficult with traditional precipitation and adsorption water treatment technologies. In the context of sustainable development, and considering that complexed heavy metals represent valuable metal resources, there is an urgent need to develop effective treatment methods for breaking down complexed heavy metals and recovering these metal resources.

[0003] Electrochemical breaking of complexed heavy metals, using electrons and water as green reaction reagents, is mild and controllable, and has attracted increasing attention. The active species generated by electrochemical anodic oxidation can selectively destroy complex ligands, releasing heavy metal ions, which can then be reduced and recovered at the cathode. However, the anode is susceptible to competition from oxygen evolution side reactions during the complex-breaking process, inhibiting its performance; simultaneously, the active metal sites are easily peroxidized, leading to metal dissolution and decreased electrode stability.

[0004] In the prior art, CN114162907A discloses a single-atom electrode and its preparation method and application. The electrode includes a metal substrate and a primary oxide layer on its surface. The primary oxide layer is rich in defects, and metal single atoms are anchored at the defects. The preparation method includes the following steps: (1) treating the metal with the primary oxide layer on its surface at high temperature in a reducing atmosphere to form a defect-rich metal substrate; (2) dripping a metal precursor solution onto the surface of the defect-rich substrate, drying it, and then treating it at high temperature in a reducing atmosphere to obtain a single-atom electrode, which can be used for catalytic treatment of wastewater. CN115925056A discloses the preparation of a phosphorus-doped suboxide / foam titanium electrode and its method for treating heavy metal wastewater. The preparation method is as follows: After cleaning, the titanium suboxide / titanium foam electrode is placed in a tube furnace with sodium hypophosphite and the titanium suboxide / titanium foam electrode arranged in the order of inert gas flow. Inert gas is introduced and heat-treated at 300-350℃. During the heat treatment, the inert gas first passes through the sodium hypophosphite, then through the titanium suboxide / titanium foam electrode and is discharged from the tube furnace. Finally, the tube furnace is naturally cooled to room temperature and post-treated to obtain the phosphorus-doped titanium suboxide / titanium foam electrode.

[0005] However, CN114162907A emphasizes the use of a reducing atmosphere to treat the surface of a titanium substrate to obtain a defect-rich oxide layer, followed by anchoring metal single atoms, resulting in a two-step synthesis of a single-atom electrode. This synthesis process is complex and requires high precision. CN115925056A prepared a phosphorus-doped suboxide / foam titanium electrode using a pyrolytic phosphorus precursor. This patent did not find that metal single atoms could be simultaneously loaded during non-metal doping; nor did it investigate whether other non-metal doping methods could improve the electrochemical complex-breaking performance of suboxide.

[0006] Therefore, developing a high-performance anode is crucial for the deep treatment of complexed heavy metal industrial wastewater and the recovery and resource utilization of heavy metals. Summary of the Invention

[0007] The purpose of this invention is to solve at least one of the above-mentioned problems by providing a non-metal-doped titanium-based metal single-atom electrode for breaking complexed heavy metals, its preparation method, and its application. This addresses the problems of poor activity and insufficient stability of electrochemical anode materials for breaking complexed heavy metals in the prior art. This solution utilizes the strong bonding interaction between the inherent oxide layer on the surface of the titanium-based material and the metal single-atom sites to fix the metal single atoms on the material surface. At the same time, non-metals are introduced to regulate the electronic structure of the metal, thereby improving the stability of the metal sites and the complex-breaking performance.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] The first aspect of this invention discloses a non-metal-doped titanium-based metal single-atom electrode for disintegrating complexed heavy metals, comprising a titanium substrate and non-metal atoms and metal single atoms respectively loaded on the surface of the titanium substrate;

[0010] The non-metallic atoms are selected from one or more of phosphorus, boron, and sulfur;

[0011] The metal single atom is selected from one or both of iron and cobalt.

[0012] Preferably, the titanium substrate includes titanium mesh, titanium felt, and titanium foam; the doping amount of the non-metallic atoms is 0.02 to 0.5 wt% of the total electrode mass; and the doping amount of the metal single atom is 0.02 to 0.5 wt% of the total electrode mass.

[0013] Preferably, the area of ​​the titanium substrate is 0.01 to 1 m². 2 .

[0014] The second aspect of this invention discloses a method for preparing a non-metallic doped titanium-based single-atom electrode for disintegrating complexed heavy metals, as described above.

[0015] If the nonmetallic atoms are phosphorus and / or sulfur, the preparation method includes the following steps:

[0016] A non-metallic precursor solution is placed at the inlet of a tube furnace; a metallic precursor solution is uniformly drop-coated onto the surface of a titanium substrate, dried, and then placed at the outlet of a tube furnace; pyrolysis is performed under a protective atmosphere to obtain the electrode.

[0017] If the non-metallic atom is boron, the preparation method includes the following steps:

[0018] A metal precursor solution is uniformly drop-coated onto the surface of a titanium substrate, followed by a non-metallic precursor solution. The substrate is then heated and pyrolyzed under a protective atmosphere to obtain the electrode.

[0019] Preferably, the metal precursor solution is a metal chloride, nitrate, or acetate, and the concentration of the metal precursor solution is 0.5–10 mg / mL.

[0020] More preferably, the concentration of the metal precursor solution is 1 mg / mL.

[0021] Preferably, the non-metallic precursor solution is as follows: if the non-metallic atom is phosphorus, the non-metallic precursor is phosphite; if the non-metallic atom is sulfur, the non-metallic precursor is at least one of thiourea, sodium sulfide, and sulfur powder; if the non-metallic atom is boron, the non-metallic precursor is boric acid or boron oxide; the concentration of the non-metallic precursor solution is 3-30 mg / mL.

[0022] Preferably, if the non-metallic atom is phosphorus and / or sulfur, the mass ratio of the non-metallic precursor to the metallic precursor is 2 to 12:1; if the non-metallic atom is boron, the mass ratio of the non-metallic precursor to the metallic precursor is 1 to 6:1.

[0023] More preferably, if the nonmetallic atom is phosphorus and / or sulfur, the mass ratio of the nonmetallic precursor to the metallic precursor is 4:1; if the nonmetallic atom is boron, the mass ratio of the nonmetallic precursor to the metallic precursor is 1:1.

[0024] Preferably, the protective atmosphere is an argon atmosphere and / or a nitrogen atmosphere.

[0025] Preferably, the pyrolysis temperature is 200–500°C and the time is 2–5 hours.

[0026] More preferably, the pyrolysis temperature is 300°C and the time is 3 hours.

[0027] The third aspect of the present invention discloses the application of a non-metallic doped titanium-based metal single-atom electrode for disintegrating complexed heavy metals as described above in the treatment of heavy metal complex wastewater.

[0028] Preferably, the heavy metal complex includes, but is not limited to, one or more of nickel ethylenediaminetetraacetate, copper ethylenediaminetetraacetate, and chromium ethylenediaminetetraacetate, and the concentration of the heavy metal complex in the wastewater is 10-100 mg / L.

[0029] Preferably, a three-electrode system is used for electrochemical complex disruption;

[0030] In the aforementioned three-electrode system:

[0031] The working electrode is the electrode as described above; the reference electrode is selected from a silver-silver chloride electrode; the counter electrode is selected from one of carbon felt, carbon cloth, graphite sheet and titanium mesh; the electrolyte is sodium sulfate solution (0.01-0.5 mol / L);

[0032] In the aforementioned electrochemical complex breaking process:

[0033] The applied voltage is 0.8–3.0V, and the reaction time is 1–3h.

[0034] The working principle of this invention is as follows:

[0035] Under energized conditions, the metal single atoms on the anode are oxidized from a lower valence state to a higher valence state, transforming into species with high oxidizing activity. These active species can attack and break the coordination bonds of the complexes formed between heavy metal ions and EDTA, thereby decomposing the complexes. Subsequently, the heavy metal ions dissociated from EDTA are reduced to the corresponding elemental metals at the cathode. During this process, the doping of non-metallic atoms can effectively modulate the electronic structure of the anode metal atoms, enhancing their stability on the anode substrate, thus exhibiting sustained complex decomposition efficiency.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1) The preparation method of the non-metal-doped titanium-based metal single-atom electrode disclosed in this invention is simple. By pyrolyzing the non-metal precursor and reacting it with the oxide layer on the surface of the titanium substrate, the non-metal-doped metal single-atom electrode is synthesized from non-metal and metal single atoms in one step. The process is simple, efficient, easy to scale up industrially, and has the feasibility of large-scale preparation.

[0038] 2) The non-metallic doped titanium-based single-atom electrode material of this invention exhibits excellent complex-breaking activity against various complexed heavy metals and good stability. Therefore, this electrode material shows great application potential in the advanced treatment of complex industrial complexed wastewater.

[0039] 3) Non-metallic doped titanium-based metal single-atom electrodes are composed of inexpensive elements, resulting in low prices and low production costs. Attached Figure Description

[0040] Figure 1The images show the XRD patterns of the phosphorus-doped titanium-based cobalt single-atom electrode (P-Co1-Ti) prepared in Example 1 of the present invention, as well as Comparative Examples 1, 2 and 3.

[0041] Figure 2 The X-ray energy dispersive spectroscopy (EDS mapping) of the P-Co1-Ti electrode prepared in Example 1 of the present invention is shown.

[0042] Figure 3 The figures show (a) the total nickel removal curve of the P-Co1-Ti electrode electrochemically breaking Ni(II)-EDTA in Test Example 1 of the present invention, and (b) the comparison of the breaking rate and total nickel removal performance between different electrodes.

[0043] Figure 4 This is a cycle stability test of the P-Co1-Ti electrode electrochemically breaking down Ni(II)-EDTA in Test Example 1 of the present invention.

[0044] Figure 5 The XRD patterns of the carbon felt cathode used for Ni reduction and recovery are shown before and after the reaction in the P-Co1-Ti electrode electrochemical complexation Ni(II)-EDTA system used for Ni reduction and recovery in Test Example 1 of the present invention.

[0045] Figure 6 The activity curves of the P-Co1-Ti electrode electrochemically breaking Cu(II)-EDTA and Cr(III)-EDTA in Example 2 of the present invention are shown.

[0046] Figure 7 The total nickel removal curves of Ni(II)-EDTA electrochemically broken down by the electrodes (a) B-Co1-Ti and (b) S-Co1-Ti in Examples 2 and 3 of the present invention are shown.

[0047] Figure 8 The XRD patterns are those of the boron-doped titanium-based cobalt single-atom electrode (P-Fe1-Ti) prepared in Example 4 of the present invention, as well as those of Comparative Examples 4, 5 and 6.

[0048] Figure 9 The X-ray energy dispersive spectroscopy (EDS mapping) of the P-Fe1-Ti electrode prepared in Example 4 of the present invention is shown.

[0049] Figure 10 The figures show (a) the total nickel removal curve of the P-Fe1-Ti electrode electrochemically breaking down Ni(II)-EDTA in Test Example 3 of the present invention, and (b) a comparison of the breakdown rate and total nickel removal performance between different electrodes.

[0050] Figure 11This is a cycle stability test of the P-Fe1-Ti electrode electrochemically breaking down Ni(II)-EDTA in Test Example 3 of the present invention.

[0051] Figure 12 The activity curves of the P-Fe1-Ti electrode electrochemically breaking Cu(II)-EDTA and Cr(III)-EDTA in Example 4 of the present invention are shown.

[0052] Figure 13 The total nickel removal curves of Ni(II)-EDTA electrochemically broken down by the electrodes (a) B-Fe1-Ti and (b) S-Fe1-Ti in Examples 5 and 6 of the present invention are shown. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0054] Unless otherwise specified, the reagents used in the following description are commercially available products, and the methods used are those known in the art.

[0055] Example 1

[0056] A method for preparing a phosphorus-doped titanium-based cobalt single-atom electrode includes the following steps:

[0057] First, cut the titanium mesh into 2*2cm pieces. 2 The titanium mesh was first acid-washed in a 0.1 mol / L oxalic acid solution at 80°C for 30 minutes, then washed three times with ethanol and water respectively, and dried in an oven at 60°C. A 3 mg / mL cobalt nitrate ethanol solution and a 3 mg / mL sodium hypophosphite aqueous solution were prepared. 100 μL of cobalt nitrate solution was uniformly drop-coated onto a titanium mesh and dried under an infrared lamp. A corundum boat containing 200 μL of sodium hypophosphite solution was placed near the inlet of a tube furnace, and the cobalt nitrate-coated titanium mesh was placed near the outlet. The mixture was treated at 300°C for 3 hours under an argon and / or nitrogen atmosphere to prepare a phosphorus-doped titanium-based cobalt single-atom electrode (P-Co1-Ti).

[0058] Characterization of the physical properties of phosphorus-doped titanium-based cobalt single-atom electrodes:

[0059] The phosphorus-doped titanium-based cobalt single-atom electrode synthesized in Example 1 was characterized by X-ray diffraction and X-ray electron spectroscopy mapping imaging techniques. Figure 1 The XRD pattern only shows diffraction peaks on the titanium substrate, indicating that there may be no cobalt or phosphorus nanoparticles on the electrode surface, which is consistent with... Figure 2 The mapping results show that the P and Co are uniformly distributed on the material surface, proving the successful fabrication of a phosphorus-doped cobalt single-atom electrode.

[0060] Compare with Example 1

[0061] Based on Example 1, sodium hypophosphite was omitted to obtain a titanium-based cobalt single-atom electrode (Co1-Ti).

[0062] Compare with Example 2

[0063] Based on Example 1, the cobalt nitrate ethanol solution was omitted to obtain a phosphorus-doped titanium-based electrode (P-Ti).

[0064] Compare with Example 3

[0065] Based on Example 1, sodium hypophosphite and cobalt nitrate ethanol solution were omitted to obtain a titanium-based electrode (Ti).

[0066] Test Example 1

[0067] Testing of the electrochemical breaking performance of phosphorus-doped titanium-based cobalt single-atom electrodes in a single-cell (single-compartment electrolytic cell) on complexed heavy metals:

[0068] A phosphorus-doped titanium-based cobalt single-atom electrode (P-Co1-Ti) was used as the anode, carbon felt as the cathode, and a mercury-mercurous sulfate electrode as the reference electrode. The reaction electrolyte was a 0.05 mol / L sodium sulfate solution; the reaction potential was 1.1 V, and the reaction time was 3 h. In the wastewater, the heavy metal complex was nickel ethylenediaminetetraacetate (Ni(II)-EDTA) at a concentration of 10 mg / L.

[0069] pass Figure 3 It was found that P-Co1-Ti exhibited the best performance in Ni(II)-EDTA complex disruption and total Ni removal. Within 3 hours, the complex disruption rate approached 100%, and the total Ni removal rate was as high as 95.4%.

[0070] Figure 4 Cyclic stability test data show that P-Co1-Ti has a total nickel removal performance of over 90% in 5 cycles, indicating good stability.

[0071] Figure 5 The XRD patterns of the carbon felt cathode before and after the reaction show that the Ni removed by electrochemical complex breaking was reduced and fixed onto the cathode carbon felt, realizing the deep treatment and resource recovery of complexed heavy metal Ni(II)-EDTA.

[0072] Test Example 2

[0073] This embodiment provides a method and application for electrochemically breaking down other complexed heavy metals using a phosphorus-doped titanium-based cobalt single-atom electrode (P-Co1-Ti electrode) prepared in Example 1:

[0074] P-Co1-Ti was used as the anode, carbon felt as the cathode, and a mercury-mercurous sulfate electrode as the reference electrode. The reaction electrolyte was a 0.05 mol / L sodium sulfate solution; the reaction potential was 1.05 V, and the reaction time was 3 h. In the wastewater, the heavy metal complexes were copper ethylenediaminetetraacetate (Cu(II)-EDTA) and chromium ethylenediaminetetraacetate (Cr(III)-EDTA), each with a concentration of 10 mg / L.

[0075] pass Figure 6 It was found that P-Co1-Ti exhibited excellent Cu(II)-EDTA complex-breaking and total Cu removal performance; within 3 hours, the complex-breaking rates of Cu(II)-EDTA and Cr(II)-EDTA were close to 100%.

[0076] Example 2

[0077] The specific steps for preparing boron-doped titanium-based cobalt single-atom electrodes are as follows:

[0078] Based on Example 1, sodium hypophosphite was omitted, and a 3 mg / mL aqueous solution of boric acid was used as the boron source to replace the phosphorus source.

[0079] The specific preparation steps are as follows: 100 μL of cobalt nitrate solution was uniformly drop-coated onto a titanium mesh, and then 100 μL of boric acid solution was drop-coated onto the titanium mesh. The mesh was then dried under an infrared lamp until no obvious liquid remained. Afterward, it was placed in a ceramic boat and then placed in a tube furnace. Under an atmosphere of argon and / or nitrogen, it was treated at 300°C for 3 hours to prepare a boron-doped titanium-based cobalt single-atom electrode (B-Co1-Ti).

[0080] The B-Co1-Ti electrode prepared in this embodiment can also be used for electrochemically breaking down complexed heavy metals (Ni(II)-EDTA, with the same testing steps as in Test Example 1). Figure 7 a).

[0081] Example 3

[0082] The specific steps for preparing a sulfur-doped titanium-based cobalt single-atom electrode are as follows:

[0083] Based on Example 1, sodium hypophosphite was omitted, and a 3 mg / mL thiourea ethanol solution was used as the sulfur source to replace the phosphorus source.

[0084] The specific preparation steps are as follows: 100 μL of cobalt nitrate solution was uniformly drop-coated onto a titanium mesh and dried under an infrared lamp until no obvious liquid remained. 200 μL of thiourea solution was drop-coated into an alumina magnetic boat and placed near the inlet of a tube furnace. The titanium mesh coated with cobalt nitrate was placed in the magnetic boat near the outlet. Under an atmosphere of argon and / or nitrogen, the mixture was treated at 300 °C for 3 h to prepare a sulfur-doped titanium-based cobalt single-atom electrode (S-Co1-Ti).

[0085] The S-Co1-Ti electrode prepared in this embodiment can also be used for electrochemically breaking down complexed heavy metals (Ni(II)-EDTA, with the same testing steps as in Test Example 1). Figure 7 b).

[0086] Example 4

[0087] The specific steps for preparing a phosphorus-doped titanium-based iron single-atom electrode are as follows:

[0088] Based on Example 1, a 3 mg / mL ferric chloride hexahydrate ethanol solution was used as the iron source to replace the cobalt nitrate ethanol solution as the cobalt source.

[0089] The specific preparation steps are as follows: 100 μL of ferric chloride hexahydrate ethanol solution was uniformly drop-coated onto a titanium mesh and dried under an infrared lamp until no obvious liquid remained. 200 μL of sodium hypophosphite was dropped into an alumina magnetic boat and placed near the inlet of a tube furnace. The titanium mesh coated with ferric chloride was placed in the magnetic boat near the outlet. Under an atmosphere of argon and / or nitrogen, the mixture was treated at 300 °C for 3 h to prepare a phosphorus-doped titanium-based single-atom iron electrode (P-Fe1-Ti).

[0090] The phosphorus-doped titanium-based single-atom iron electrode synthesized in Example 4 was characterized by X-ray diffraction and X-ray electron spectroscopy mapping imaging techniques. Figure 8 The XRD pattern only shows diffraction peaks on the titanium substrate, indicating that there may be no iron or phosphorus nanoparticles on the electrode surface, which is consistent with... Figure 9 The mapping results show that the P and Fe on the material surface are uniformly distributed, proving that the phosphorus-doped iron single-atom electrode has been successfully prepared.

[0091] Compare with Example 4

[0092] Based on Example 4, the sodium hypophosphite solution was omitted to obtain a titanium-based iron single-atom electrode (Fe1-Ti).

[0093] Compare with Example 5

[0094] Based on Example 4, the ferric chloride solution was omitted, resulting in a phosphorus-doped titanium-based electrode (P-Ti).

[0095] Compare with Example 6

[0096] Based on Example 4, the ferric chloride and sodium hypophosphite solution were omitted to obtain a titanium-based electrode (Ti).

[0097] Test Example 3

[0098] Application of phosphorus-doped titanium-based iron single-atom electrodes in the electrochemical breaking of complexed heavy metals in a single cell:

[0099] A phosphorus-doped titanium-based iron single-atom electrode (P-Fe1-Ti) was used as the anode, a carbon felt as the cathode, and a silver-silver chloride electrode as the reference electrode. The reaction electrolyte was a 0.05 mol / L sodium sulfate solution; the reaction potential was 1.8 V, and the reaction time was 3 h. The concentration of nickel ethylenediaminetetraacetate (Ni(II)-EDTA) in the wastewater was 10 mg / L.

[0100] pass Figure 10 It was found that P-Fe1-Ti exhibited the best performance in Ni(II)-EDTA complex disruption and total Ni removal. Within 3 hours, the complex disruption rate approached 100%, and the total Ni removal rate was as high as 95.7%.

[0101] Figure 11 Cyclic stability test data show that P-Fe1-Ti has a total nickel removal performance of over 93% in 5 cycles, indicating good stability.

[0102] Test Example 4

[0103] This embodiment provides a method and application for electrochemically breaking down other complexed heavy metals using a phosphorus-doped titanium-based iron single-atom electrode (P-Fe1-Ti electrode) prepared in Example 4.

[0104] P-Fe1-Ti was used as the anode, carbon felt as the cathode, and a silver-silver chloride electrode as the reference electrode. The reaction electrolyte was a 0.05 mol / L sodium sulfate solution; the reaction potential was 1.8 V, and the reaction time was 3 h. The heavy metal complexes were copper ethylenediaminetetraacetate (Cu(II)-EDTA) and chromium ethylenediaminetetraacetate (Cr(III)-EDTA), each with a concentration of 10 mg / L.

[0105] pass Figure 12 It was found that P-Fe1-Ti exhibited the best Cu(II)-EDTA complex disruption and total Cu removal performance. Within 3 hours, the complex disruption rates of both Cu(II)-EDTA and Cr(II)-EDTA were close to 100%.

[0106] Example 5

[0107] The specific steps for preparing boron-doped titanium-based iron single-atom electrodes are as follows:

[0108] Based on Example 4, sodium hypophosphite was omitted, and a 3 mg / mL aqueous solution of boric acid was used as the boron source to replace the phosphorus source.

[0109] The specific preparation steps are as follows: 100 μL of ferric chloride hexahydrate solution was uniformly drop-coated onto a titanium mesh. After drying, 200 μL of boric acid solution was added, and the mesh was dried under an infrared lamp until no obvious liquid remained. Then, the mesh was placed in a ceramic boat and placed in a tube furnace. Under an atmosphere of argon and / or nitrogen, the mesh was treated at 300°C for 3 hours to prepare a boron-doped titanium-based single-atom iron electrode (B-Fe1-Ti).

[0110] The B-Fe1-Ti electrode prepared in this embodiment can also be used for electrochemically breaking down complexed heavy metals (Ni(II)-EDTA, with the same testing steps as in Test Example 3). Figure 13 a).

[0111] Example 6

[0112] The specific steps for preparing a sulfur-doped titanium-based iron single-atom electrode are as follows:

[0113] Based on Example 4, sodium hypophosphite was omitted, and a 3 mg / mL thiourea ethanol solution was used as the sulfur source to replace the phosphorus source.

[0114] The specific preparation steps are as follows: 100 μL of ferric chloride hexahydrate solution was uniformly drop-coated onto a titanium mesh and dried under an infrared lamp until no obvious liquid remained. 200 μL of thiourea was drop-coated into a corundum magnetic boat and placed near the gas inlet of a tube furnace. The titanium mesh coated with ferric nitrate was placed in a magnetic boat near the gas outlet. Under an atmosphere of argon and / or nitrogen, the mixture was treated at 300 °C for 3 h to prepare a sulfur-doped titanium-based iron single-atom electrode (S-Fe1-Ti).

[0115] The S-Fe1-Ti electrode prepared in this embodiment can also be used for electrochemically breaking down complexed heavy metals (Ni(II)-EDTA, with the same testing steps as in Test Example 3). Figure 13 b).

[0116] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals, characterized in that, This includes a titanium substrate, and non-metallic atoms and metallic single atoms respectively loaded on the surface of the titanium substrate; The non-metallic atoms are selected from one or more of phosphorus, boron, and sulfur; the doping amount of the non-metallic atoms is 0.02~0.5wt% of the total electrode mass. The metal single atom is selected from one or both of iron and cobalt; the doping amount of the metal single atom is 0.02~0.5wt% of the total electrode mass; The non-metal-doped titanium-based metal single-atom electrode utilizes the strong bonding interaction between the inherent oxide layer on the titanium substrate surface and the metal single-atom sites to fix the metal single atoms on the material surface. At the same time, non-metal atoms are introduced to regulate the electronic structure of the metal single atoms, thereby improving the stability and complex breaking performance of the metal single-atom sites. and, If the nonmetallic atoms are phosphorus and / or sulfur, the preparation method includes the following steps: A non-metallic precursor solution is placed at the inlet of a tube furnace; a metallic precursor solution is uniformly drop-coated onto the surface of a titanium substrate, dried, and then placed at the outlet of a tube furnace; pyrolysis is performed under a protective atmosphere to obtain the electrode. If the non-metallic atom is boron, the preparation method includes the following steps: A metal precursor solution is uniformly drop-coated onto the surface of a titanium substrate, followed by a non-metallic precursor solution. The substrate is then heated and pyrolyzed under a protective atmosphere to obtain the electrode.

2. The non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, The titanium substrate includes titanium mesh, titanium felt, and titanium foam.

3. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, The metal precursor solution is a metal chloride, nitrate, or acetate, and the concentration of the metal precursor solution is 0.5~10 mg / mL.

4. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, The non-metallic precursor solution is as follows: if the non-metallic atom is phosphorus, the non-metallic precursor is phosphite; if the non-metallic atom is sulfur, the non-metallic precursor is at least one of thiourea, sodium sulfide, and sulfur powder; if the non-metallic atom is boron, the non-metallic precursor is boric acid or boron oxide; the concentration of the non-metallic precursor solution is 3~30 mg / mL.

5. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, If the nonmetallic atom is phosphorus and / or sulfur, the mass ratio of the nonmetallic precursor to the metallic precursor is 2~12:1; if the nonmetallic atom is boron, the mass ratio of the nonmetallic precursor to the metallic precursor is 1~6:

1.

6. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, The protective atmosphere is an argon atmosphere and / or a nitrogen atmosphere.

7. A non-metallic doped titanium-based single-atom electrode for disentangled heavy metals according to claim 1, characterized in that, The pyrolysis temperature is 200~500℃ and the time is 2~5h.

8. The application of a non-metallic doped titanium-based single-atom electrode for disintegrating complexed heavy metals as described in any one of claims 1 to 7 in the treatment of heavy metal complex wastewater.

9. The application according to claim 8, characterized in that, Electrochemical complex disruption was performed using a three-electrode system. In the aforementioned three-electrode system: The working electrode is the electrode as described in any one of claims 1 to 7; the reference electrode is selected from a silver-silver chloride electrode; the counter electrode is selected from one of carbon felt, carbon cloth, graphite sheet and titanium mesh; the electrolyte is a sodium sulfate solution. In the aforementioned electrochemical complex breaking process: The applied voltage is 0.8~3.0V, and the reaction time is 1~3h.

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