Ni-doped SbO2-SnO2 electrode based on citric acid system electrodeposition as well as preparation and application of Ni-doped SbO2-SnO2 electrode

Abstract

The invention discloses a Ni-doped SbO2-SnO2 electrode based on electrolytic deposition of a citric acid system as well as preparation and application of the Ni-doped SbO2-SnO2 electrode. Carrying out polishing, alkali treatment and acid treatment on the titanium sheet substrate; tin salt, antimony salt, nickel salt and citric acid are dissolved in water and subjected to ultrasonic treatment, standing is conducted till complete dissolution is achieved, and electro-deposition liquid is obtained; a certain amount of electro-deposition liquid is taken and added into an electro-deposition device, a counter electrode, a reference electrode and the treated titanium sheet substrate are selected as working electrodes, constant current is applied for electro-deposition, and after electro-deposition is completed, the working electrodes are taken out and dried; and putting the dried electrode into a ceramic boat, and calcining in an air atmosphere to obtain the Ni-doped SbO2-SnO2 electrode. The Ni-doped SbO2-SnO2 provided by the invention can be directly used for electro-catalytic synthesis of ozone, and an electro-catalytic test result shows that in 0.5 M of KNO3 electrolyte, 26.98% of Faraday efficiency and corresponding 1258 mg h <-1 > g <-1 > of ozone yield are realized under 2.7 V vs.Ag / AgCl constant voltage. And after a stability test of 100 mA cm to 272 h, the Faraday efficiency can still be kept basically unchanged, and the industrial application potential is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical catalysis, and in particular to a Ni-doped SbO2-SnO2 electrode electrode deposited based on a citric acid system, and the preparation and application thereof. Background Art

[0002] Ozone (O3) is composed of three oxygen atoms. It is a pungent gas at normal temperature and pressure. It is unstable and easily decomposes into oxygen.

[0003] The O3 molecule has a V-shaped structure, which leads to asymmetric electron distribution, making the O3 molecule highly reactive, easy to react with electron donors, and exhibiting strong oxidizing properties.

[0004] Due to its strong oxidizing ability, clean and pollution-free nature and broad-spectrum bactericidal ability, O3 is widely used in industrial wastewater treatment, paper bleaching, aquaculture disinfection and food industry.

[0005] Currently, the main methods for synthesizing O₃ include corona discharge, ultraviolet irradiation, and electrocatalytic synthesis. Corona discharge is one of the most commonly used ozone production technologies in industry. Its operating principle is based on the phenomenon of gas discharge, where a high-voltage electric field causes oxygen molecules to dissociate and recombine into O₃. Corona discharge is currently the most mature ozone production technology, offering high efficiency and stability. Ozone concentration and output can be precisely controlled by adjusting the voltage, frequency, and gas flow rate. It is suitable for both small-scale laboratory research and large-scale industrial production. However, this method has certain limitations in practical application due to its high energy consumption, complex and expensive equipment, and the production of nitrogen oxides as byproducts, which can affect O₃ purity and pollute the environment. However, due to its high and stable O₃ yield, this method remains the most mainstream method for O₃ production in industry.

[0006] Electrocatalytic ozone synthesis is considered a highly promising method for producing O₃ due to its advantages of simple equipment, high selectivity, and cleanliness. Its reaction principle is to form ozone on the electrode surface through electrochemical anodic water oxidation. However, the theoretical potential of the electrocatalytic O₃ synthesis reaction is higher than that of the oxygen evolution reaction, and the theoretical potential of H₂O₂ generation is very close to that of the electrocatalytic ozone synthesis reaction. The existence of these competing reactions greatly limits the selectivity of the electrocatalytic O₃ synthesis reaction. Furthermore, the theoretical potential of the electrocatalytic synthesis reaction is relatively high, and reactions at high potentials may cause corrosion, shedding, and deactivation of the anode catalyst.

[0007] Therefore, the current research focus of electrocatalytic O3 synthesis reaction is mainly on improving the selectivity and stability of catalysts for O3 synthesis. Summary of the Invention

[0008] The purpose of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned prior art and to provide a Ni-doped SbO2-SnO2 electrode based on citric acid system electrodeposition that is easy to prepare, has excellent stability and high selectivity, and its preparation and application.

[0009] Citric acid forms a complex sol with components in the electrodeposition solution. This complex sol transforms into a gel layer during the electrode drying process, effectively filling microcracks on the electrode surface, resulting in a uniform and stable coating. This gives the Ni-doped SbO2-SnO2 electrode material excellent electrochemical stability. The nickel-containing sol layer formed on the surface synergizes with the electrodeposition process, promoting Ni enrichment on the electrode surface and inducing the formation of oxygen vacancy defects, thereby enhancing the electrocatalytic ozone synthesis performance. This strategy allows for the effective synthesis of efficient and stable electrocatalytic ozone synthesis catalysts, providing a simple and efficient catalyst preparation method for electrochemical ozone production.

[0010] The present invention is achieved through the following technical solutions:

[0011] A method for preparing a Ni-doped SbO2-SnO2 electrode by electroplating in a citric acid system comprises the following steps:

[0012] 1) polishing, alkali treatment and acid treatment of the titanium sheet substrate;

[0013] 2) dissolving tin salt, antimony salt, nickel salt and citric acid in water, ultrasonicating and allowing to stand until completely dissolved to obtain an electrodeposition solution;

[0014] 3) adding the electrodeposition solution obtained in step 2) to an electrodeposition apparatus, selecting a counter electrode and a reference electrode, using the treated titanium substrate as a working electrode, applying a constant current for electrodeposition, and removing and drying the working electrode after electrodeposition is complete;

[0015] 4) The dried electrode is placed in a ceramic boat and calcined in an air atmosphere to obtain a Ni-doped SbO2-SnO2 electrode.

[0016] In step 1), the polishing refers to removing surface oxides by polishing, and polishing is performed using 400, 800, and 1200 mesh sandpaper in sequence, and each side of the titanium sheet is polished with each sandpaper for 10 to 30 minutes.

[0017] In step 1), the alkali used in the alkali treatment is any one of sodium hydroxide and potassium hydroxide; the titanium sheet is placed in a 1-2M alkali solution, the temperature of the alkali solution is maintained at 80-90° C., and the treatment is performed for 1 hour to remove oil stains on the surface of the titanium sheet;

[0018] In step 1), the acid treatment involves placing the titanium sheet in a 1.5-3M oxalic acid solution maintained at 85-95°C for 2 hours to etch the titanium sheet. After the treatment is complete, the titanium sheet is removed, cleaned, and stored in anhydrous ethanol.

[0019] In step 2), the tin salt is any one of tin tetrachloride and tin dichloride; the antimony salt is antimony chloride; the nickel salt is any one of nickel chloride and nickel sulfate; and the water used is ultrapure water;

[0020] In step 2), the concentrations of tin salt, antimony salt and citric acid are 0.02M, 0.02M and 0.3M respectively; the concentration of nickel salt is changed from 0 to 0.03M to obtain electrode materials with different nickel doping amounts;

[0021] In step 2), the ultrasonic treatment is to ultrasonicate the mixed solution for 0.5 to 1 hour.

[0022] In step 3), 20 to 50 mL of the electrodeposition solution is added to the electrodeposition device;

[0023] In step 3), the electrodeposition temperature is maintained at 90° C. during the electrodeposition process;

[0024] In step 3), the counter electrode is a carbon rod or the titanium sheet treated in step 1), and the reference electrode is an Ag / AgCl electrode.

[0025] In step 3), the titanium sheet substrate used has an area of 1 to 4 cm 2 , the electrodeposition current is -20 mA cm -2 , the electrodeposition time is 10 to 30 minutes;

[0026] In step 3), the working electrode is taken out and placed in a forced air drying oven at 60-80° C. for 12 h.

[0027] In step 4), the calcination is carried out in a tube furnace or a muffle furnace.

[0028] In step 4), the calcination conditions are to raise the temperature to 600° C. over 170 minutes and keep the temperature at 600° C. for 2 to 3 hours.

[0029] The Ni-doped SbO2-SnO2 electrode obtained by the above method; the application of the Ni-doped SbO2-SnO2 electrode in electrocatalytic synthesis of ozone; the application refers to: electrocatalytic synthesis of ozone using a three-electrode system, specifically comprising the following steps:

[0030] Ni-doped SbO2-SnO2 electrode was used as the working electrode, carbon rod and Ag / AgCl electrode were used as the counter electrode and reference electrode, respectively;

[0031] Ozone is produced by electrolysis in an electrolytic cell using potassium nitrate solution or potassium perchlorate solution as the electrolyte.

[0032] Compared with the prior art, the present invention has the following advantages and effects:

[0033] The preparation process of the present invention is green, simple and efficient, and the Ni-doped SbO2-SnO2 electrode is synthesized by a simple method of electrodeposition followed by calcination.

[0034] The catalyst of the present invention can be directly used as a working electrode for electrocatalytic production of ozone without subsequent treatment.

[0035] The citric acid in the electrodeposition solution system of the present invention can form a complex sol with the components in the electrodeposition solution. The complex sol can be transformed into a gel layer during the electrode drying process, effectively filling the microcracks on the electrode surface, thereby obtaining a uniform and stable coating, greatly improving the electrochemical stability of the electrode. -2 The battery can be operated continuously for 72 hours at a current density of 100 nm without significant voltage changes.

[0036] The Ni-doped SbO2-SnO2 electrode of the present invention exhibits excellent catalytic activity in the electrocatalytic synthesis of ozone, achieving a Faradaic efficiency of 26.98% and a corresponding 1258 mg h -1 g -1 ozone production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 SEM images of the SbO2-SnO2 (SS) and SbO2-SnO2 (NSS) electrodes with different Ni doping amounts prepared in Examples 1 to 4;

[0038] Figure 2 This is the EDS spectrum of the 2-Ni-SbO2-SnO2 (2-NSS) electrode prepared in Example 3;

[0039] Figure 3 TEM image and EDS spectrum of the 2-Ni-SbO2-SnO2 (2-NSS) electrode prepared in Example 3;

[0040] Figure 4 Performance test diagram of electrocatalytic synthesis of O3 of SbO2-SnO2(SS) and SbO2-SnO2(NSS) electrodes with different Ni doping amounts prepared in Examples 1 to 4;

[0041] Figure 5 The stability performance test diagram of the 2-NSS electrode prepared in Example 3 and the XRD comparison diagram before and after the stability test;

[0042] Figure 6This is a graph showing the standard curve of the detection method for the electrocatalytic synthesis of O3 using the SS prepared in Examples 1 to 4 and NSS with different Ni doping amounts. DETAILED DESCRIPTION

[0043] The present invention will be described in further detail below with reference to specific examples. The experimental methods used in the examples of the present invention are conventional methods unless otherwise specified, and the materials and reagents used are all commercially available unless otherwise specified.

[0044] Example 1:

[0045] A method for preparing a SbO2-SnO2 electrode using a citric acid electrodeposition system, the preparation method comprising the following steps:

[0046] (1) First, take a large piece of titanium sheet and grind it with 400, 800, and 1200 grit sandpaper in sequence. Grind both sides of the titanium sheet with each sandpaper for 30 minutes, and then cut the large piece of titanium sheet into small pieces of 1x2 cm.

[0047] (2) The titanium sheet was then placed in a 1.5M sodium hydroxide solution at 85°C for 1 hour to remove oil stains from the surface. The titanium sheet was then removed, rinsed with deionized water, and then immersed in a 1.5M oxalic acid solution at 80°C for 2 hours for etching. Finally, the titanium sheet was stored in an ethanol solution to isolate oxygen and prevent oxidation.

[0048] (3) Prepare the electroplating solution: The composition of the electroplating solution is 0.3M citric acid, 0.02M SnCl2 and 0.02M SbCl3. Ultrasonicate the mixed solution for 1 hour and then let it stand until the substances in the solution are completely dissolved. Add 20mL of the electroplating solution to a 50mL single cell and place it on a heating table at a constant temperature of 90℃ for use.

[0049] (4) Remove the two titanium sheets from the ethanol solution, rinse with deionized water, and dry them. Use two clamped electrodes to serve as the anode and cathode, respectively, and use an Ag / AgCl electrode as the reference electrode. The anode titanium sheet serves as the sacrificial electrode, and the cathode titanium sheet serves as the working electrode. Immerse the two titanium sheets 1 cm into the electrodeposition solution and keep them parallel and approximately 1 cm apart. Electrodeposit for 30 min at a current of -20 mA.

[0050] (5) After the electrodeposition is completed, the cathode sample is taken out and dried in a forced air drying oven at 60°C for 12 h, and then placed in a ceramic boat and transferred to a tube furnace for calcination.

[0051] (6) The specific calcination parameters are heating for 170 min, keeping at 600 °C for 2 h, and calcining in air atmosphere to obtain SnO2-SbO2 samples, which are marked as SS.

[0052] Example 2:

[0053] A method for preparing a Ni-doped SbO2-SnO2 electrode using a citric acid electrodeposition system, wherein the steps are the same as those in Example 1 except for the following steps:

[0054] Nickel chloride was added to the electrodeposition solution in step (3) to make the nickel chloride concentration of the final electrodeposition solution 0.01 M. The Ni-doped SbO2-SnO2 electrode obtained in Example 2 was labeled 1-NSS.

[0055] Example 3:

[0056] A method for preparing a Ni-doped SbO2-SnO2 electrode using a citric acid electrodeposition system, wherein the steps are the same as those in Example 1 except for the following steps:

[0057] Nickel chloride was added to the electrodeposition solution in step (3) to make the nickel chloride concentration of the final electrodeposition solution 0.02 M. The Ni-doped SbO2-SnO2 electrode obtained in Example 3 was labeled 2-NSS.

[0058] Example 4:

[0059] A method for preparing a Ni-doped SbO2-SnO2 electrode using a citric acid electrodeposition system, wherein the steps are the same as those in Example 1 except for the following steps:

[0060] Nickel chloride was added to the electrodeposition solution in step (3) to make the nickel chloride concentration of the final electrodeposition solution 0.03 M. The Ni-doped SbO2-SnO2 electrode obtained in Example 3 was labeled 3-NSS.

[0061] The scanning electron microscope images of the SbO2-SnO2 (SS) obtained in Example 1 and the Ni-doped SbO2-SnO2 (NSS) prepared in Examples 2 to 4 are as follows: Figure 1 The surface of the SS material is a large block structure, while the surface of the NSS materials with different Ni doping amounts are all rough and uniform pine-tree-like dendrite structures, indicating that Ni doping can effectively regulate the growth process of tin-antimony metal particles during electrodeposition, thereby forming a flocculent dendrite structure with a larger specific surface area.

[0062] The EDS spectrum and transmission electron microscopy images of 2-NSS obtained in Example 3 are as follows: Figure 2 、 Figure 3As shown in the EDS spectrum, it can be seen that Sn, Sb, and Ni elements are present and evenly distributed on the NSS surface. The transmission electron microscopy image clearly shows the lattice fringes and interface distribution of SnO2 and SbO2. The lattice fringes are 0.333nm, 0.261nm, and 0.175nm, corresponding to the (110), (101), and (211) crystal planes of SnO2, respectively. The spacing is 0.303nm and 0.289nm, corresponding to the (112) and (004) crystal planes of SbO2, respectively.

[0063] Figure 4 The electrocatalytic ozone synthesis performance test diagram of SS prepared in Examples 1 to 4 and NSS with different Ni doping amounts is shown in Figure 2. Figure 4 It can be seen that the O3 production of 2-NSS increases with the increase of potential. At a potential of 3.5 V vs. Ag / AgCl, the O3 production is 2956.6 mg h -1 g -1 The Faradaic efficiency of 2-NSS first increases and then decreases with increasing potential, reaching a maximum of 26.98% at 2.7 V vs. Ag / AgCl. SS exhibits poor electrocatalytic O3 synthesis performance, with a FE of only 2.7% at 2.5 V vs. Ag / AgCl. Ni doping significantly improves the EOP performance of NSS. The FEs of 1-NSS, 2-NSS, and 3-NSS are 15.2%, 23.4%, and 20.2%, respectively. 2-NSS exhibits the highest electrocatalytic O3 synthesis performance, demonstrating excellent potential for practical applications.

[0064] The stability performance test of the 2-NSS electrode prepared in Example 3 is as follows Figure 5 As shown, at 100mA cm -2 A 72-hour electrochemical stability test under 40°C (100°F) showed no significant change in the test voltage of the 2-NSS material. A comparison of the XRD diffraction patterns before and after the test revealed that the XRD peaks of the 2-NSS remained essentially unchanged, demonstrating the excellent structural stability of the 2-NSS prepared using the citric acid system. After the test, the electrode surface maintained a flocculent structure of stacked sheets, with no significant changes in its morphology, demonstrating the excellent structural stability of the 2-NSS material prepared using the citric acid system.

[0065] Figure 6Determination of the standard curve of the detection method for the electrocatalytic synthesis of O3 by SS and NSS with different Ni doping amounts prepared in Examples 1 to 4. The ozone production performance test is a three-electrode system with Ag / AgCl as the reference electrode and a carbon rod as the counter electrode. The reaction is carried out in an H-type electrolytic cell. 94mL KNO3 and 6mL 1mM indigo solution are added to the anode chamber, and 100mL KNO3 is added to the cathode chamber. Magnetic stirring is added during the reaction at a speed of 200rpm to ensure that ozone and indigo react completely. The test is carried out using an electrochemical workstation, and the solutions before and after the reaction are taken to determine their absorbance. According to the difference in absorbance and the above-mentioned standard curve, the relationship between the difference in absorbance and the concentration of the solution is obtained:

[0066] C = 5.59 × ΔABS (Formula 1)

[0067] The unit of C is ppm, and ΔABS is the absorbance difference between the blank and the electrolyte after reaction at 610 nm.

[0068] As described above, the present invention can be implemented better.

[0069] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing Ni-doped SbO2-SnO2 electrodes by electrodeposition in a citric acid system, characterized in that: The following steps are involved: 1) polishing, alkali treatment and acid treatment of the titanium sheet substrate; 2) dissolving tin salt, antimony salt, nickel salt and citric acid in water, ultrasonicating and allowing to stand until completely dissolved to obtain an electrodeposition solution; 3) adding the electrodeposition solution obtained in step 2) to an electrodeposition apparatus, selecting a counter electrode and a reference electrode, using the treated titanium substrate as a working electrode, applying a constant current for electrodeposition, and removing and drying the working electrode after electrodeposition is complete; 4) The dried electrode is placed in a ceramic boat and calcined in an air atmosphere to obtain a Ni-doped SbO2-SnO2 electrode.

2. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: The polishing in step 1) refers to removing surface oxides by polishing, and polishing is performed with 400, 800, and 1200 mesh sandpaper in sequence, and each side of the titanium sheet is polished with each sandpaper for 10 to 30 minutes. The alkali used in the alkali treatment in step 1) is one of sodium hydroxide and potassium hydroxide; the titanium sheet is placed in a 1-2M alkali solution, the temperature of the alkali solution is maintained at 80-90° C., and the treatment is performed for 1 hour to remove oil stains on the surface of the titanium sheet; The acid treatment in step 1) is to place the titanium sheet in a 1.5-3M oxalic acid solution, with the temperature of the oxalic acid solution maintained at 85-95° C., for 2 hours to etch the titanium sheet. After the treatment is completed, the titanium sheet is taken out, cleaned and stored in anhydrous ethanol.

3. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: In step 2), the tin salt is one of tin tetrachloride and tin dichloride; the antimony salt is antimony chloride; the nickel salt is one of nickel chloride and nickel sulfate; and the water used is ultrapure water; In step 2), the concentrations of tin salt, antimony salt, and citric acid are 0.02M, 0.02M, and 0.3M, respectively; the concentration of nickel salt is varied from 0 to 0.03M to obtain electrode materials with different nickel doping amounts; The ultrasonic treatment in step 2) is to ultrasonicate the mixed solution for 0.5 to 1 hour.

4. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: In step 3), 20 to 50 mL of the electrodeposition solution is added to the electrodeposition device; In step 3), the electrodeposition temperature is maintained at 90° C. during the electrodeposition process; In step 3), the counter electrode is a carbon rod or the titanium sheet treated in step 1), and the reference electrode is an Ag / AgCl electrode.

5. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: In step 3), the titanium sheet substrate used has an area of 1 to 4 cm 2 , the electrodeposition current is -20 mA cm -2 , the electrodeposition time is 10 to 30 minutes; In step 3), the working electrode is taken out and placed in a forced air drying oven at 60-80° C. for 12 h.

6. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: In step 4), the calcination is carried out in a tube furnace or a muffle furnace.

7. The method for preparing Ni-doped SbO2-SnO2 electrodes by citric acid system electrodeposition according to claim 1, characterized in that: In step 4), the calcination conditions are to raise the temperature to 600° C. over 170 minutes and keep the temperature at 600° C. for 2 to 3 hours.

8. A Ni-doped SbO2-SnO2 electrode obtained by the method according to any one of claims 1 to 7.

9. Use of the Ni-doped SbO2-SnO2 electrode according to claim 8 in electrocatalytic synthesis of ozone.

10. Use of the Ni-doped SbO2-SnO2 electrode according to claim 9 in electrocatalytic ozone synthesis; the application refers to: electrocatalytic ozone synthesis using a three-electrode system, specifically comprising the following steps: Ni-doped SbO2-SnO2 electrode was used as the working electrode, carbon rod and Ag / AgCl electrode were used as the counter electrode and reference electrode, respectively; Ozone is produced by electrolysis in an electrolytic cell using potassium nitrate solution or potassium perchlorate solution as the electrolyte.

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