A self-supporting three-dimensional porous electrocatalytic anode and its preparation method and application

Abstract

The present invention discloses a self-supporting three-dimensional porous electrocatalytic anode, its preparation method, and application. To address the problems of existing three-dimensional electrocatalytic anodes, such as small pore size, disconnected pore structure, and slow degradation of organic pollutants, the present invention provides a self-supporting three-dimensional porous electrocatalytic anode with abundant and interconnected macropores. The anode is based on an electrocatalytically active substance and uses monosaccharides as pore-forming agents, and is prepared through a forming and heat treatment process. The electrocatalytic anode provided by the present invention can efficiently, rapidly, and stably electrocatalytically oxidize and remove difficult-to-degrade organic pollutants.

Description

Technical Field

[0001] The invention relates to a self-supporting three-dimensional porous electrocatalytic anode and a preparation method and application thereof, belonging to the technical fields of electrochemistry and environmental protection. Background Art

[0002] In the process of electrocatalytic oxidation to remove pollutants, the anode catalytic electrode determines the oxidation removal effect of pollutants. Currently, there are two types of anodes prepared based on electrocatalytically active material powders: a planar structure anode with a substrate coated with a powder catalyst and a self-supporting three-dimensional anode made by pressing the powder into a tablet. Compared with the planar structure anode with a flat substrate loaded with a powder catalyst, the self-supporting three-dimensional anode has the advantages of simple composition, uniform structure, and stable properties, which is more conducive to the rapid and stable electrochemical reaction. In the process of preparing the self-supporting three-dimensional anode, adding a pore-forming agent can form pores inside and on the surface, increasing the specific surface area and exposed active sites of the self-supporting three-dimensional anode and the migration of pollutants in the pores, thereby accelerating the oxidation degradation of organic pollutants. However, different pore-forming agents have different elemental composition, morphology, particle size, and decomposition temperature, which have a significant impact on the structure and performance of the final three-dimensional porous electrocatalytic anode.

[0003] Currently, commonly used pore-forming agents include ammonium bicarbonate, ammonium carbonate, carbon materials, starch, and polymers. However, three-dimensional porous electrocatalytic anodes prepared using these pore-forming agents still suffer from shortcomings such as small pore size and disconnected pore structure when oxidizing organic pollutants. This leads to problems with mass transfer and slow degradation kinetics in these three-dimensional electrocatalytic anodes.

[0004] Monosaccharides can be micron-sized particles. They are simple in composition, low in molecular weight, and readily decompose upon heating, producing only gaseous carbon dioxide and water. Therefore, they can simultaneously create macropores and completely decompose. Therefore, using monosaccharides as pore-forming agents is more advantageous for preparing three-dimensional porous electrocatalytic anodes rich in macropores and interconnected pores, thereby enabling faster mass transfer and oxidative degradation of organic pollutants. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-supporting three-dimensional porous electrocatalytic anode with abundant macropores, and its preparation method and application, so as to solve the problems of small pore size and disconnected pores in existing three-dimensional porous anodes, slow mass transfer and low degradation efficiency during the electrocatalytic removal of organic pollutants.

[0006] According to a first aspect of the present invention, the present invention provides a self-supporting three-dimensional porous electrocatalytic anode, characterized in that it comprises the following steps:

[0007] Step 1: uniformly mixing the electrocatalytic active material and the monosaccharide using a vortex mixer to obtain a mixed powder;

[0008] Step 2: Add the binder to the mixed powder obtained in step 1 using a vortex mixer and mix them evenly to obtain a mixed slurry for pressing;

[0009] Step 3: Using a corresponding mold, the mixed slurry obtained in step 2 is pressed into a desired shape to obtain a three-dimensional anode precursor;

[0010] Step 4: Pyrolyze the anode precursor obtained in step 3 to obtain a self-supporting three-dimensional porous electrocatalytic anode.

[0011] Wherein, the monosaccharides in step 1 include fructose, galactose and sucrose.

[0012] Preferably, the electrocatalytically active material is one or a combination of TiO2, SnO2, SnO2-Sb.

[0013] Preferably, the binder is one or a combination of liquid paraffin, methyl cellulose, and polyvinylidene fluoride.

[0014] Preferably, in step 1, the mass ratio of the electrocatalytic active material to fructose is 1:0.05 to 1:0.3.

[0015] Preferably, the pressure required for the pressing and forming in step 2 is 10 to 25 bar, and the action time is 5 to 15 minutes.

[0016] Preferably, the pyrolysis atmosphere in step three is air, the pyrolysis temperature is 600-1000° C., and the pyrolysis time is 1-12 hours.

[0017] According to a second aspect of the present invention, a self-supporting three-dimensional porous electrocatalytic anode is provided, characterized by a pore size range of 20-100 nm. Organic pollutants can diffuse rapidly within the pores and undergo electrocatalytic oxidation reactions at the active sites, thereby improving the degradation efficiency of the organic pollutants.

[0018] According to a third aspect of the present invention, the present invention provides a use of a self-supporting three-dimensional porous electrocatalytic anode in electrocatalytic oxidation degradation of pollutants.

[0019] The beneficial effects of the present invention are embodied in:

[0020] The present invention utilizes monosaccharides as pore-forming agents. These simple ingredients leave no residue after pyrolysis, resulting in an electrocatalytic anode with abundant, interconnected macropores. This exposes more active sites and larger transport channels, facilitating rapid electrocatalytic oxidation reactions at the anode. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A photo of the self-supporting three-dimensional porous electrocatalytic anode prepared in Example 1

[0022] Figure 2 This is a scanning electron microscope photo of the electrocatalytic active material in Example 1

[0023] Figure 3 This is a scanning electron microscope photo of the self-supporting three-dimensional porous electrocatalytic anode prepared in Example 1.

[0024] Figure 4 The pore size distribution of the three-dimensional porous electrocatalytic anode prepared in Example 1

[0025] Figure 5 The results of the cyclic stability test of the degradation of the herbicide atrazine using the three-dimensional porous electrocatalytic anode in Example 1 are shown in FIG. DETAILED DESCRIPTION

[0026] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. The following content is merely an example and illustration of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described, or replace them with similar methods. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they shall fall within the scope of protection of the present invention.

[0027] Example 1

[0028] The preparation process of the three-dimensional porous electrocatalytic anode includes the following steps:

[0029] Step 1: 1.2 g SnO2-Sb nanopowder and 0.36 g fructose were thoroughly mixed using a vortex mixer (10 min);

[0030] Step 2: Add liquid paraffin and mix using a vortex mixer for 10 minutes to obtain a mixed slurry;

[0031] Step 3: evenly distribute the mixed slurry obtained in step 2 in a mold, place the mold in a tablet press, apply a vertical pressure of 20 bar for 5 minutes, and obtain a formed three-dimensional anode precursor;

[0032] Step 4: The anode precursor obtained in step 3 is pyrolyzed in air at 1000℃ for 6 hours to remove fructose, and a self-supporting three-dimensional porous electrocatalytic anode is obtained. Figure 1 shown.

[0033] The scanning electron microscope photo of the nano antimony tin oxide in this embodiment is as follows: Figure 2 The scanning electron microscope image of the obtained self-supporting three-dimensional porous electrocatalytic anode is shown in Figure 3 As shown, the pore size distribution is Figure 4The electrocatalytic anode has abundant macropores with pore sizes ranging from 20 to 100 nm.

[0034] Application of this three-dimensional porous electrocatalytic anode in pollutant degradation:

[0035] The herbicide atrazine was degraded in a single-chamber electrolytic cell using the self-supporting three-dimensional porous electrode as the anode, a platinum sheet as the cathode, a silver / silver chloride electrode as the reference electrode, and 0.1M Na2SO4 as the electrolyte. Figure 5 The results of the cyclic stability test for atrazine degradation are shown in Figure 2. As can be seen from the figure, the self-supporting three-dimensional porous electrocatalytic anode can efficiently and rapidly degrade atrazine and has high long-term stability.

[0036] Example 2

[0037] The preparation process of the three-dimensional porous electrocatalytic anode includes the following steps:

[0038] Step 1: 1.2 g SnO2-Sb nanopowder and 0.18 g galactose were thoroughly mixed using a vortex mixer (10 min);

[0039] Step 2: Add methylcellulose and mix using a vortex mixer for 10 minutes to obtain a mixed powder;

[0040] Step 3: Evenly distribute the mixed powder obtained in step 2 in a mold, place the mold in a tablet press, and apply a vertical pressure of 20 bar for 5 minutes to obtain a formed three-dimensional anode precursor;

[0041] Step 4: The anode precursor obtained in step 3 is pyrolyzed in air at 1000° C. for 6 hours to remove galactose, thereby obtaining a self-supporting three-dimensional porous electrocatalytic anode.

[0042] Example 3

[0043] The preparation process of the three-dimensional porous electrocatalytic anode includes the following steps:

[0044] Step 1: 1.2 g TiO2 powder and 0.36 g fructose were thoroughly mixed using a vortex mixer (10 min);

[0045] Step 2: Add liquid paraffin and mix using a vortex mixer for 10 minutes to obtain a mixed slurry;

[0046] Step 3: evenly distribute the mixed slurry obtained in step 2 in a tablet pressing mold, place the tablet pressing mold in a tablet pressing machine, apply a vertical pressure of 10 bar for 5 minutes, and obtain a formed three-dimensional anode precursor;

[0047] Step 4: The anode precursor obtained in step 3 is subjected to high-temperature pyrolysis at 600° C. in air for 6 hours to remove fructose, thereby obtaining a self-supporting three-dimensional porous electrocatalytic anode.

[0048] Example 4

[0049] The preparation process of the three-dimensional porous electrocatalytic anode includes the following steps:

[0050] Step 1: 1.2 g SnO2-Sb nanopowder and 0.36 g fructose were thoroughly mixed using a vortex mixer (10 min);

[0051] Step 2: Add liquid paraffin and mix using a vortex mixer for 10 minutes to obtain a mixed slurry;

[0052] Step 3: evenly distribute the mixed slurry obtained in step 2 in a mold, place the mold in a tablet press, apply a vertical pressure of 25 bar for 5 minutes, and obtain a formed three-dimensional anode precursor;

[0053] Step 4: The anode precursor obtained in step 3 is subjected to high-temperature pyrolysis at 800° C. in air for 6 hours to remove fructose, thereby obtaining a self-supporting three-dimensional porous electrocatalytic anode.

[0054] The above are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a self-supporting three-dimensional porous electrocatalytic anode, characterized in that: The following steps are involved: Step 1: uniformly mixing the electrocatalytic active material and the monosaccharide to obtain a mixed powder; Step 2: adding a binder to the mixed powder obtained in step 1 and mixing them uniformly to obtain a mixed slurry; Step 3: Pressing the mixed slurry obtained in step 2 into a shape to obtain a three-dimensional anode precursor; Step 4: Pyrolyzing the anode precursor in step 3 in air to obtain a self-supporting three-dimensional porous electrocatalytic anode; The monosaccharide is one of fructose and galactose or a combination thereof; the electrocatalytic active material is one of TiO2, SnO2, SnO2-Sb or a combination thereof.

2. The method for preparing a self-supporting three-dimensional porous electrocatalytic anode according to claim 1, characterized in that: The binder is one or a combination of paraffin, methyl cellulose, and polyvinylidene fluoride.

3. The method for preparing a self-supporting three-dimensional porous electrocatalytic anode according to claim 2, characterized in that: In the step 1, the mass ratio of the electrocatalytic active material to the monosaccharide is 1:0.05 to 1:0.

3.

4. The method for preparing a self-supporting three-dimensional porous electrocatalytic anode according to claim 3, characterized in that: The pressure required for the pressing and forming in step 2 is 10 to 25 bar, and the action time is 5 to 15 minutes.

5. The method for preparing a self-supporting three-dimensional porous electrocatalytic anode according to claim 4, characterized in that: The pyrolysis temperature in step 3 is 600-1000° C., and the pyrolysis time is 1-12 hours.

6. A self-supporting three-dimensional porous electrocatalytic anode prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The pore size range is 20-100 nm.

7. Use of the self-supporting three-dimensional porous electrocatalytic anode according to claim 6 in electrocatalytic oxidation degradation of pollutants.

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