A copper / zinc / antimony co-doped titanium-based tin dioxide anode material and its preparation and application

Abstract

The invention relates to a copper / zinc / antimony co-doped titanium-based tin dioxide anode material and a preparation method and application thereof. The specific preparation method comprises the following steps: step (1): grinding a titanium plate surface step by step with sandpaper, rinsing the surface with deionized water, immersing the surface in acetone for ultrasonic degreasing, and etching the degreased titanium plate in a hydrochloric acid solution; step (2): adding SnCl2·2H2O, Sb2O3, Cu(NO3)2·3H2O and Zn(NO3)2·6H2O to isopropanol, dripping hydrochloric acid for dissolution, stirring evenly, and obtaining a coating solution; step (3): coating the coating solution prepared in step (2) evenly on the surface of the titanium plate treated in step (1), drying in an oven, calcining in a muffle furnace, and cooling; and repeating the steps for multiple times; and step (4): annealing the titanium plate treated in step (3) in an annealing furnace, and then cooling the titanium plate to room temperature along with the annealing furnace. The copper / zinc / antimony co-doped titanium-based tin dioxide anode material prepared by the present invention has the advantages of high oxygen evolution potential, multiple active sites, high electrocatalytic activity and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of electrocatalytic electrode materials, and specifically relates to a copper / zinc / antimony co-doped titanium-based-tin dioxide anode material and a preparation method and application thereof. Background Art

[0002] As a new water treatment process, indirect electrocatalytic oxidation has been proven to be effective in fading and degrading azo dyes in water. Its main feature is that it can oxidize water at the anode to generate hydroxyl radicals (·OH), which are second only to fluorine in oxidizing power, and completely mineralize pollutants into water and carbon dioxide. Compared with other anodic metal oxide materials, tin dioxide SnO2 has relatively good electrocatalytic activity, is easy to manufacture, and is cheap, making it a typical electrocatalytic active material.

[0003] Anode materials are the key factor in the ·OH yield in indirect electrocatalytic oxidation systems. The ·OH yield of SnO2 anode materials is limited by their low conductivity, oxygen evolution potential, and fewer active sites. Therefore, it is urgent to develop SnO2 anode materials with high oxygen evolution potential and multiple active sites. Summary of the invention

[0004] The purpose of the present invention is to provide a copper / zinc / antimony co-doped titanium-based-tin dioxide anode material and its preparation and application.

[0005] The object of the present invention can be achieved by the following technical scheme: A method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material, comprising the following steps:

[0006] Step (1): grinding the surface of the titanium plate step by step with sandpaper, rinsing it with deionized water, and then immersing it in acetone for ultrasonic degreasing, and etching the degreased titanium plate in a hydrochloric acid solution;

[0007] Step (2): add SnCl2·2H2O, Sb2O3, Cu(NO3)2·3H2O and Zn(NO3)2·6H2O to isopropanol in sequence, and add 5 drops of hydrochloric acid to dissolve, stir evenly, and obtain a coating solution;

[0008] Step (3): uniformly coating the coating solution prepared in step (2) on the surface of the titanium plate treated in step (1), drying in an oven, calcining in a muffle furnace, and cooling; repeating the process multiple times;

[0009] Step (4): annealing the titanium plate treated in step (3) in an annealing furnace, and then cooling the titanium plate to room temperature in the annealing furnace to obtain a copper / zinc / antimony co-doped titanium-tin dioxide anode material.

[0010] Furthermore, the ultrasonic degreasing time in step (1) is 30 to 40 minutes, and the mass fraction of the hydrochloric acid solution is 20%.

[0011] Furthermore, the etching temperature in step (1) is 80-95° C., and the etching time is 70-100 min.

[0012] Preferably, the etching time is 90 to 100 minutes.

[0013] Furthermore, in the coating solution described in step (2), Sn 2+ The concentration is 0.1~0.5mol / L, the molar ratio of SnCl2·2H2O and Sb2O3 is 100:(1~10); Cu 2+ and Zn 2+ The total concentration is 25~50mmol / L, Cu 2+ and Zn 2+ The concentration ratio is 7:(1~5).

[0014] Furthermore, the drying temperature in step (3) is 100-130° C., and the drying time is 5-20 min.

[0015] Furthermore, the calcination temperature in step (3) is 450-600° C., and the calcination time is 5-20 min.

[0016] Furthermore, the cooling in step (3) refers to natural cooling to room temperature in air.

[0017] Furthermore, the number of repetitions in step (3) is 10 to 20 times.

[0018] Preferably, the repetition number is 12 to 15 times.

[0019] Furthermore, the annealing temperature in step (4) is 450-550° C., and the annealing time is 0.5-1.5 h.

[0020] Preferably, the annealing time is 1.0 h.

[0021] The second object of the present invention is to provide a copper / zinc / antimony co-doped titanium-based-tin dioxide anode material prepared by the above method.

[0022] Anode materials are the key factor in the ·OH yield in indirect electrocatalytic oxidation systems. The ·OH yield of SnO2 anode materials is limited by lower conductivity, oxygen evolution potential and fewer active sites. SnO2 materials co-doped with Cu, Zn and Sb ions have higher oxygen evolution potential and more active sites. Therefore, copper, zinc and antimony are added during the preparation of titanium-tin dioxide anode materials.

[0023] The third object of the present invention is to provide an application of a copper / zinc / antimony co-doped titanium-based tin dioxide anode material, wherein the copper / zinc / antimony co-doped titanium-based tin dioxide anode material is applied in an indirect electrocatalytic oxidation system to increase the production of ·OH on the anode surface.

[0024] The fourth object of the present invention is to provide an application of a copper / zinc / antimony co-doped titanium-based-tin dioxide anode material, and to apply the copper / zinc / antimony co-doped titanium-based-tin dioxide anode material in an indirect electrocatalytic oxidation system to degrade organic dyes; to apply the copper / zinc / antimony co-doped titanium-based-tin dioxide anode material to remove the organic dye Acid Red 18 to improve the chemical oxygen demand removal rate of Acid Red 18; the anode in the indirect electrocatalytic oxidation system is a copper / zinc / antimony co-doped titanium-based-tin dioxide anode material, and the cathode is made of 304 or 316 stainless steel.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The method for preparing the copper / zinc / antimony co-doped titanium-based-tin dioxide anode material of the present invention is simple, and the prepared copper / zinc / antimony co-doped titanium-based-tin dioxide anode material has the advantages of high oxygen evolution potential, multiple active sites, high electrocatalytic activity and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a scanning electron microscope image of the Ti / SnO2-Sb-Cu-Zn anode prepared in Example 1;

[0028] Figure 2 This is a scanning electron microscope image of the Ti / SnO2-Sb anode prepared in Comparative Example 1;

[0029] Figure 3 Linear sweep voltammetry curves of the Ti / SnO2-Sb-Cu-Zn anode prepared in Example 1 and the Ti / SnO2-Sb anode prepared in Comparative Example 1;

[0030] Figure 4 A graph showing the removal rate of Acid Red 18 in an electrocatalytic system in which the anodes are the Ti / SnO2-Sb-Cu-Zn anode prepared in Example 1 and the Ti / SnO2-Sb anode prepared in Comparative Example 1;

[0031] Figure 5 The figure is a graph of the removal rate of Acid Red 18 before and after using a quencher in an electrocatalytic system in which the anode is a Ti / SnO2-Sb-Cu-Zn anode prepared in Example 1;

[0032] Figure 6The schematic diagram of the preparation process of Ti / SnO2-Sb-Cu-Zn anode and the electrocatalytic oxidation system;

[0033] Figure 7 For different Cu 2+ With Zn 2+ Chemical oxygen demand removal rate of Acid Red 18 by proportional Ti / SnO2-Sb-Cu-Zn anode. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0035] The reagents used in the following examples are all commercially available reagents; the various equipment used in the following examples are all commercially available equipment.

[0036] Example 1

[0037] like Figure 6 As shown, the pretreated titanium plate is used as the Ti / SnO2-Sb-Cu-Zn anode substrate. The pretreatment method of the titanium plate is as follows: First, the surface of the titanium plate is polished step by step with sandpaper and rinsed with deionized water. Subsequently, the titanium plate is immersed in acetone for ultrasonic degreasing for 30 minutes to remove the dirt on the surface. Next, the titanium plate is etched in 20% hydrochloric acid and 90°C for 90 minutes. Finally, the etched titanium plate is rinsed with deionized water and stored in anhydrous ethanol.

[0038] The Ti / SnO2-Sb-Cu-Zn anode was prepared by thermal decomposition. The preparation method is as follows: First, SnCl2·2H2O, Sb2O3, Cu(NO3)2·3H2O, and Zn(NO3)2·6H2O were added to isopropanol in a material ratio of 100:5:5.18:2.22, and 5 drops of hydrochloric acid were added to dissolve to obtain a coating solution, wherein Sn 2+ The concentration is 0.5mol / L. Subsequently, the coating solution is evenly applied to the surface of the pretreated titanium plate with a brush. Then, the test piece is sent to an oven and dried at 120°C for 10 minutes. The dried test piece is immediately sent to a muffle furnace and calcined at 550°C for 10 minutes, then taken out and naturally cooled to room temperature in the air. After the steps of brushing, drying, calcining, and cooling are repeated 15 times, the test piece is annealed at 550°C for 1 hour, and then cooled to room temperature with the furnace.

[0039] Example 2

[0040] The difference from Example 1 is that the molar ratios of Cu(NO3)2·3H2O and Zn(NO3)2·6H2O used are 3:7, 1:1 and 4:1 respectively, and the other reaction conditions and operating steps are the same as those in Example 1.

[0041] Comparative Example 1

[0042] The pretreated titanium plate was used as the Ti / SnO2-Sb anode substrate. The pretreatment method of the titanium plate is as follows: First, the surface of the titanium plate is polished step by step with sandpaper and rinsed with deionized water. Subsequently, the titanium plate is immersed in acetone for ultrasonic degreasing for 30 minutes to remove the dirt on the surface. Next, the titanium plate is etched in 20% hydrochloric acid and 90°C for 90 minutes. Finally, the etched titanium plate is rinsed with deionized water and stored in anhydrous ethanol.

[0043] The Ti / SnO2-Sb anode was prepared by thermal decomposition. The preparation method is as follows: First, SnCl2·2H2O and Sb2O3 were added to isopropanol in a substance ratio of 100:5 and 5 drops of hydrochloric acid were added to dissolve to obtain a coating solution, wherein Sn 2 + The concentration is 0.5mol / L. Subsequently, the coating solution is evenly applied to the surface of the pretreated titanium plate with a brush. Then, the test piece is sent to an oven and dried at 120°C for 10 minutes. The dried test piece is immediately sent to a muffle furnace and calcined at 550°C for 10 minutes, then taken out and naturally cooled to room temperature in the air. After the brushing step is repeated 15 times, the test piece is annealed at 550°C for 1 hour, and then cooled to room temperature with the furnace.

[0044] The scanning electron microscope image of the Ti / SnO2-Sb-Cu-Zn anode prepared in Example 1 is as follows: Figure 1 As shown, the scanning electron microscope image of the Ti / SnO2-Sb anode prepared in Comparative Example 1 is as follows Figure 2 As shown, it can be seen that the cracks on the surface of the Ti / SnO2-Sb-Cu-Zn electrode are relatively smaller and the surface roughness is also increased, which is beneficial to increasing the real surface area and life of the coating surface.

[0045] Specific application process:

[0046] (1) In the three-electrode electrochemical test system, a platinum electrode was used as the auxiliary electrode, a saturated calomel electrode was used as the reference electrode, and a Ti / SnO2-Sb (1×1 cm 2 ) sheet electrode or Ti / SnO2-Sb-Cu-Zn(1×1cm 2 ) electrode. The electrolyte used in the electrochemical test was 0.05 mol·L -1 Na2SO4, pH is 7. Figure 3As shown, it can be seen that the oxygen evolution potential of the Ti / SnO2-Sb-Cu-Zn anode is increased by 0.06 V compared with the Ti / SnO2-Sb anode, which is beneficial to inhibiting the oxygen evolution side reaction.

[0047] (2) The cathode is 304 stainless steel (3×5cm 2 ) electrode, the anode is Ti / SnO2-Sb (3×5cm 2 ) sheet electrode or Ti / SnO2-Sb-Cu-Zn(3×5cm 2 ) electrode, the electrolyte is 0.4 mol·L -1 The indirect electrocatalytic oxidation system with Na2SO4 and pH 7 was applied to degrade the organic dye Acid Red 18. The concentration of Acid Red 18 was 400 mg·L -1 , the working current density is 100mA·cm -2 The concentration of Acid Red 18 in the quenching degradation experiment was 400 mg·L -1 , ethanol or tert-butyl alcohol concentration is 0.331mmol / L, working current density is 100mA·cm -2 .like Figure 4 As shown in the figure, the electrocatalytic system with Ti / SnO2-Sb-Cu-Zn as the anode achieved a removal rate of 99.50% for Acid Red 18 within 30 minutes. Figure 5 As shown in the figure, after the electrocatalytic oxidation system was quenched by ethanol (ETAB) to quench ·OH and tert-butyl alcohol (TBA) to quench sulfate radicals, the removal rate of Acid Red 18 in 30 minutes decreased from 99.50% to about 14.30%. Therefore, 85.70% of the degradation of Acid Red 18 was attributed to the ·OH generated on the surface of the Ti / SnO2-Sb-Cu-Zn anode. Therefore, the Ti / SnO2-Sb-Cu-Zn anode has better electrocatalytic activity and more active sites than the traditional Ti / SnO2-Sb anode, which will be a useful feature in practical applications.

[0048] Figure 7 For different Cu 2+ With Zn 2+ Figure 2 shows the chemical oxygen demand removal rate of acid red 18 by Ti / SnO2-Sb-Cu-Zn anode with different ratios, where S is the synergistic value. 2+ With Zn 2+ The highest chemical oxygen demand removal rate was obtained when the ratio was 7:3 and the synergy value S>1, indicating that Cu 2+ With Zn 2+ The optimal modification ratio is 7:3.

[0049] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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 present invention should be within the scope of protection of the present invention.

Claims

1. A method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material, characterized in that: The following steps are involved: Step (1): grinding the surface of the titanium plate step by step with sandpaper, rinsing it with deionized water, and then immersing it in acetone for ultrasonic degreasing, and etching the degreased titanium plate in a hydrochloric acid solution; Step (2): Add SnCl2·2H2O, Sb2O3, Cu(NO3)2·3H2O and Zn(NO3)2·6H2O to isopropanol, and drop hydrochloric acid to dissolve, and stir evenly to obtain a coating solution; Step (3): uniformly coating the coating solution prepared in step (2) on the surface of the titanium plate treated in step (1), drying in an oven, calcining in a muffle furnace, and cooling; Repeat multiple times; Step (4): annealing the titanium plate treated in step (3) in an annealing furnace, and then cooling the titanium plate to room temperature in the annealing furnace to obtain a copper / zinc / antimony co-doped titanium-tin dioxide anode material.

2. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The ultrasonic degreasing time in step (1) is 30 to 40 minutes, and the mass fraction of the hydrochloric acid solution is 20%.

3. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The etching temperature in step (1) is 80-95° C., and the etching time is 70-100 min.

4. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: In the coating solution described in step (2), Sn 2+ The concentration is 0.1~0.5mol / L, the molar ratio of SnCl2·2H2O and Sb2O3 is 100:(1~10); Cu 2+ and Zn 2+ The total concentration is 25~50mmol / L, Cu 2+ and Zn 2+ The concentration ratio is 7:(1~5).

5. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The drying temperature in step (3) is 100-130° C., and the drying time is 5-20 min.

6. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The calcination temperature in step (3) is 450-600° C., and the calcination time is 5-20 min.

7. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The cooling described in step (3) refers to natural cooling to room temperature in air; the number of repetitions described in step (3) is 10 to 20 times.

8. The method for preparing a copper / zinc / antimony co-doped titanium-based tin dioxide anode material according to claim 1, characterized in that: The annealing temperature in step (4) is 450-550° C., and the annealing time is 0.5-1.5 h.

9. A copper / zinc / antimony co-doped titanium-based tin dioxide anode material prepared by the method of claim 1.

10. An application of the copper / zinc / antimony co-doped titanium-based-tin dioxide anode material as claimed in claim 9, characterized in that: The copper / zinc / antimony co-doped titanium-based-tin dioxide anode material is applied in an indirect electrocatalytic oxidation system to degrade organic dyes; the anode in the indirect electrocatalytic oxidation system is the copper / zinc / antimony co-doped titanium-based-tin dioxide anode material, and the cathode is 304 or 316 stainless steel.

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