Preparation method of nano TiO2 (at) AC (at) GPs electrocatalytic anode material

Abstract

The invention relates to the technical field of electro-catalytic material synthesis, in particular to a preparation method of a nano TiO2 (at) AC (at) GPs electro-catalytic anode material, which comprises the following steps: firstly, depositing an amorphous carbon layer AC on the surface of graphite flake GPs by adopting a chemical vapor deposition method to obtain an AC (at) GPs composite material; cTAB is dissolved in a methanol / deionized water mixed solution and stirred evenly to obtain a solution A, a titanium sulfate solution is added into the solution A to obtain a precursor solution B, the precursor solution B and the AC (at) GPs composite material are mixed and then subjected to a hydrothermal reaction, after the reaction, a sample is washed, dried and roasted, and the nano TiO2 (at) AC (at) GPs electrocatalytic anode material is obtained. The preparation process is simple and efficient, the obtained nano TiO2 (at) AC (at) GPs electro-catalytic anode material has excellent electro-catalytic activity and cycling stability, the problems that a traditional graphite anode material is poor in electro-catalytic performance and the like are solved, and the nano TiO2 (at) AC (at) GPs electro-catalytic anode material has wide industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalytic material synthesis, and particularly relates to a preparation method of a nano-TiO2@AC@GPs electrocatalytic anode material. Background Art

[0002] With the rapid development of industrial economy, the problem of environmental pollution is becoming increasingly serious, and the treatment of wastewater is an important part of environmental pollution control. The electrocatalytic oxidation technology has received extensive attention in the fields of wastewater treatment and pollutant degradation due to its advantages of high efficiency, controllability, and no secondary pollution. Among them, the electrocatalytic anode material, as one of the core components of the electrocatalytic technology, its performance directly affects the efficiency and stability of the entire electrocatalytic system.

[0003] Currently, the commonly used electrocatalytic anode materials include titanium-based coated electrodes (such as DSA electrodes), diamond film electrodes, graphite electrodes, etc. Traditional graphite electrodes have problems such as uneven conductivity, few surface active sites, and easy oxidation loss, which limit their application at high current densities. Therefore, how to improve the electrocatalytic activity and stability of graphite-based anode materials has become an urgent technical problem to be solved.

[0004] TiO2, as an excellent photocatalyst and electrocatalyst support, has good chemical stability and corrosion resistance. Loading nano-TiO2 on carbon-based materials can effectively improve its electron transport ability and catalytic activity. However, in the prior art, there is a lack of a simple and efficient method to uniformly and stably anchor nano-TiO2 on the surface of the graphite matrix and realize its chemical epitaxial growth to enhance the interfacial binding force and catalytic performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a nano-TiO2@AC@GPs electrocatalytic anode material. By a simple and efficient method, an amorphous carbon layer is deposited on the graphite sheet as an intermediate layer, and then TiO2 is chemically epitaxially grown on the surface of the amorphous carbon layer by a hydrothermal method, so that TiO2 grows uniformly on the surface of the substrate, improving the interfacial binding force and stability between TiO2 and the substrate, enhancing the electrocatalytic effect and cyclic stability of the material, and solving the problems such as poor electrocatalytic performance of traditional graphite anode materials.

[0006] The present invention is specifically realized through the following technical solutions. A preparation method of a nano-TiO2@AC@GPs electrocatalytic anode material according to the present invention includes the following steps: (1) Deposition of amorphous carbon coating: Using methane as a carbon source, a layer of amorphous carbon layer AC is deposited on the surface of the graphite sheet GPs by chemical vapor deposition to obtain an AC@GPs composite material; (2) Preparation of the precursor solution: Cetyltrimethylammonium bromide was dissolved in a mixed solution of methanol and deionized water to obtain solution A, with the concentration of cetyltrimethylammonium bromide in solution A being 2 - 4 g / L; titanium sulfate solution was added to solution A and stirred evenly to obtain solution B; (3) Hydrothermal synthesis of nano - TiO₂: The AC@GPs composite material obtained in step (1) and solution B obtained in step (2) were jointly transferred to a hydrothermal reaction kettle, and hydrothermal reaction was carried out at 120 - 200 °C, enabling the epitaxial growth of TiO₂ nanomaterials on the AC coating surface of the AC@GPs composite material; (4) Post - treatment: After the hydrothermal reaction ended, the sample was taken out and successively subjected to washing, drying, and high - temperature calcination treatments to obtain the nano - TiO₂@AC@GPs electrocatalytic anode material.

[0007] Further, the process parameters of the chemical vapor deposition method in step (1) were: deposition temperature 800 - 1100 °C, reaction time 30 - 120 min, and the protective atmosphere was argon or nitrogen.

[0008] Further, the volume ratio of methanol to deionized water in the mixed solution of step (2) was 1:1 - 3:1.

[0009] Further, the concentration of Ti in solution B of step (2) 4+ was controlled at 0.0045 - 0.0083 mol / L.

[0010] Further, the hydrothermal reaction time in step (3) was 6 - 24 h.

[0011] Further, in step (4), the sample was successively washed 6 times with deionized water and ethanol alternately (the sample was washed with deionized water for the 1st, 3rd, and 5th times, and with absolute ethanol for the 2nd, 4th, and 6th times). The washed sample was dried in an oven at 80 °C, and the high - temperature calcination was carried out under an inert gas. The calcination temperature was 300 - 600 °C, and the calcination time was 1 - 4 h.

[0012] Further, in the TiO₂@AC@GPs electrocatalytic anode material finally prepared according to the foregoing preparation method, TiO₂ was anatase type, TiO₂ grew evenly in small particle form on the surface of AC@GPs, the TiO₂ particle size was uniform, and the average diameter was 25 - 50 nm.

[0013] The present invention also provides an application of the TiO2@AC@GPs electrocatalytic anode material prepared by the above preparation method in the electrocatalytic degradation of organic wastewater, especially for the electrocatalytic degradation of the organic dye Rhodamine B. Under the same conditions, the degradation rate of the organic dye Rhodamine B by the TiO2@AC@GPs electrocatalytic anode material is much greater than that of the original graphite flakes GPs and the AC@GPs composite material. The rate constant of the first-order kinetic equation for the degradation of Rhodamine B by the TiO2@AC@GPs electrocatalytic anode material is 6 times that of the original graphite flakes.

[0014] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the present invention can achieve considerable technological progressiveness and practicability, and has wide utilization value. It has at least the following advantages: By introducing an amorphous carbon intermediate layer on the surface of the graphite flakes, the present invention enhances the nucleation and growth ability of subsequent nano-TiO2, improves the overall interfacial bonding strength of the material, enhances the stability and service life of the material, and obtains an electrocatalytic anode material with excellent cycling performance and catalytic performance. The chemical vapor deposition method (CVD) and the hydrothermal method adopted are both mature and easy-to-scale-up industrial technologies, suitable for large-scale production.

[0015] Compared with the original graphite flakes GPs and the AC@GPs composite material, the finally prepared nano-TiO2@AC@GPs electrocatalytic anode material of the present invention has more excellent electrocatalytic activity, cycling stability and corrosion resistance. After 1680 min and 14 electrocatalytic cycling experiments, the degradation rate of the organic dye Rhodamine B remains within a reasonable fluctuation range, and the electrocatalytic effect is stable and reliable. Under the same conditions, the degradation effect of the nano-TiO2@AC@GPs electrocatalytic anode material on the organic dye Rhodamine B is much greater than that of the original graphite flakes, showing excellent application effects in the fields of organic wastewater treatment and electrochemical oxidation degradation of pollutants.

[0016] No toxic and harmful reagents are used in the material preparation process of the present invention, which conforms to the development direction of green chemistry. The raw materials are few, and the preparation process is simple and efficient. It solves the problem of poor electrocatalytic performance of traditional graphite anode materials and has broad industrial application prospects in the field of wastewater treatment. Description of the Drawings

[0017] Figure 1(a) is the SEM image of the original graphite flakes used in Example 1.

[0018] Figure 1(b) is the SEM image of the AC@GPs composite material obtained in step (1) of Example 1.

[0019] Figure 2(a) is the Raman spectrum of the original graphite flakes used in Example 1.

[0020] Figure 2(b) is the Raman spectrum of the AC@GPs composite material obtained in step (1) of Example 1.

[0021] Figure 3 is the X-ray diffraction (XRD) pattern of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1.

[0022] Figure 4 is the photocurrent curve of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1.

[0023] Figure 5(a) is the SEM image of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 at a magnification of 30 times.

[0024] Figure 5(b) is the SEM image of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 at a magnification of 20,000 times.

[0025] Figure 5(c) is the SEM image of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 at a magnification of 100,000 times.

[0026] Figure 6 is the SEM image of the TiO2@GPs electrocatalytic anode material prepared in Comparative Example 1.

[0027] Figure 7 is the curve of the degradation rate of organic dye Rhodamine B with the degradation time by the original graphite sheet, the AC@GPs composite material obtained in step (1) of Example 1, and the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1.

[0028] Figure 8 is the curve of the degradation rate of organic dye Rhodamine B with the degradation time by the TiO2@GPs material prepared in Comparative Example 1.

[0029] Figure 9 is the first-order kinetic curve of the degradation of organic dye Rhodamine B by the original graphite sheet, the AC@GPs composite material obtained in step (1) of Example 1, and the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1.

[0030] Figure 10 is the diagram of 14 electrocatalytic degradation cycles of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 for organic dye Rhodamine B. Detailed implementation mode

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will, in conjunction with specific embodiments, clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0032] The following uses specific embodiments to elaborate on the present invention in detail. For those not specified in the following embodiments, they are all carried out according to conventional conditions or conditions recommended by the manufacturer. For the raw materials and reagents not specified for the manufacturer, they are all conventional products that can be obtained through commercial purchase. The high-purity graphite sheets used in the embodiments are purchased from Dongguan Tianwang Graphite Products Factory. For the ethanol used to wash the product in the following embodiments, anhydrous ethanol can be used, or an ethanol solution with a mass concentration of 95% can be used. Example 1

[0033] (1) Take a high-purity graphite sheet (GPs) with a thickness of 2 mm. After ultrasonic cleaning with acetone, place it in a CVD reaction furnace. Introduce argon as the protective gas (argon flow rate: 180 SCCM). Heat the reaction furnace to 950 °C, introduce methane gas (methane flow rate: 60 SCCM), and keep the reaction for 60 min to deposit an amorphous carbon layer AC on the surface of the graphite sheet, obtaining an AC@GPs composite material. (2) Weigh 0.2 g of CTAB and dissolve it in a 50 mL methanol / deionized water (volume ratio of methanol to deionized water is 2:1) mixed solution to obtain solution A; add 10 mL of 0.05 mol / L Ti(SO4)2 solution to solution A and stir evenly to obtain solution B. (3) Transfer the AC@GPs composite material obtained in step (1) and solution B obtained in step (2) to a hydrothermal reaction kettle and carry out a hydrothermal reaction at 160 °C for 12 h to enable the chemical epitaxial growth of TiO2 on the surface of the AC coating. (4) After the hydrothermal reaction is completed, take out the sample and wash it alternately with deionized water and ethanol 6 times (wash the sample with deionized water for the 1st, 3rd, and 5th times, and wash the sample with anhydrous ethanol for the 2nd, 4th, and 6th times). Dry the washed sample in an oven at 80 °C, and then calcine it in an argon atmosphere at 400 °C for 2 h to obtain a nano-TiO2@AC@GPs electrocatalytic anode material. Example 2

[0034] (1) Take high-purity graphite sheets (GPs) with a thickness of 2 mm. After ultrasonic cleaning with acetone, place them in a CVD reaction furnace. Introduce argon gas as the protective gas (argon gas flow rate: 180 SCCM). Heat the reaction furnace to 1000 °C, introduce methane gas (methane gas flow rate: 60 SCCM), and maintain the reaction for 60 min to deposit an amorphous carbon layer AC on the surface of the graphite sheets, obtaining AC@GPs composites; (2) Weigh 0.1 g of CTAB and dissolve it in a 50 mL mixed solution of methanol / deionized water (the volume ratio of methanol to deionized water is 2:1) to obtain solution A; add 10 mL of 0.05 mol / L Ti(SO4)2 solution to solution A and stir evenly to obtain solution B; (3) Transfer the AC@GPs composites obtained in step (1) and solution B obtained in step (2) to a hydrothermal reaction kettle together, and carry out a hydrothermal reaction at 160 °C for 10 h to enable the chemical epitaxial growth of TiO2 on the surface of the AC coating; (4) After the hydrothermal reaction is completed, take out the samples and wash them alternately with deionized water and ethanol 6 times (wash the samples with deionized water for the 1st, 3rd, and 5th times, and wash the samples with absolute ethanol for the 2nd, 4th, and 6th times). Dry the washed samples in an oven at 80 °C, and then calcine them at 400 °C for 2 h in an argon atmosphere to obtain the nano-TiO2@AC@GPs electrocatalytic anode material. Example 3

[0035] (1) Take high-purity graphite sheets (GPs) with a thickness of 2 mm. After ultrasonic cleaning with acetone, place them in a CVD reaction furnace. Introduce nitrogen gas as the protective gas (nitrogen gas flow rate: 200 SCCM). Heat the reaction furnace to 950 °C, introduce methane gas (methane gas flow rate: 60 SCCM), and maintain the reaction for 30 min to deposit an amorphous carbon layer AC on the surface of the graphite sheets, obtaining AC@GPs composites; (2) Weigh 0.2 g of CTAB and dissolve it in a 50 mL mixed solution of methanol / deionized water (the volume ratio of methanol to deionized water is 2:1) to obtain solution A; add 10 mL of 0.05 mol / L Ti(SO4)2 solution to solution A and stir evenly to obtain solution B; (3) Transfer the AC@GPs composites obtained in step (1) and solution B obtained in step (2) to a hydrothermal reaction kettle together, and carry out a hydrothermal reaction at 160 °C for 14 h to enable the chemical epitaxial growth of TiO2 on the surface of the AC coating; After the hydrothermal reaction, the sample was taken out and washed alternately with deionized water and ethanol 6 times (the sample was washed with deionized water for the 1st, 3rd, and 5th times, and with absolute ethanol for the 2nd, 4th, and 6th times). The washed sample was dried in an oven at 80 °C and then calcined in an argon atmosphere at 400 °C for 2 h to obtain the nano-TiO₂@AC@GPs electrocatalytic anode material. Example 4

[0036] (1) A high-purity graphite sheet (GPs) with a thickness of 2 mm was taken, ultrasonically cleaned with acetone, placed in a CVD reaction furnace, nitrogen was introduced as a protective gas (nitrogen flow rate: 200 SCCM), the reaction furnace was heated to 1000 °C, methane gas was introduced (methane flow rate: 60 SCCM), and the reaction was maintained for 30 min to deposit an amorphous carbon layer AC on the surface of the graphite sheet to obtain the AC@GPs composite material; (2) 0.1 g of CTAB was weighed and dissolved in 50 mL of a methanol / deionized water mixed solution (the volume ratio of methanol to deionized water was 2:1) to obtain solution A; 5 mL of 0.05 mol / L Ti(SO₄)₂ solution was added to solution A and stirred evenly to obtain solution B; (3) The AC@GPs composite material obtained in step (1) and solution B obtained in step (2) were jointly transferred to a hydrothermal reaction kettle and subjected to hydrothermal reaction at 160 °C for 12 h to enable the chemical epitaxial growth of TiO₂ on the surface of the AC coating; (4) After the hydrothermal reaction, the sample was taken out and washed alternately with deionized water and ethanol 6 times (the sample was washed with deionized water for the 1st, 3rd, and 5th times, and with absolute ethanol for the 2nd, 4th, and 6th times). The washed sample was dried in an oven at 80 °C and then calcined in an argon atmosphere at 500 °C for 2 h to obtain the nano-TiO₂@AC@GPs electrocatalytic anode material. Example 5

[0037] (1) A high-purity graphite sheet (GPs) with a thickness of 2 mm was taken, ultrasonically cleaned with acetone, placed in a CVD reaction furnace, argon was introduced as a protective gas (argon flow rate: 180 SCCM), the reaction furnace was heated to 950 °C, methane gas was introduced (methane flow rate: 60 SCCM), and the reaction was maintained for 60 min to deposit an amorphous carbon layer AC on the surface of the graphite sheet to obtain the AC@GPs composite material; (2) 0.15 g of CTAB was weighed and dissolved in 50 mL of a methanol / deionized water mixed solution (the volume ratio of methanol to deionized water was 2:1) to obtain solution A; 8 mL of 0.05 mol / L Ti(SO₄)₂ solution was added to solution A and stirred evenly to obtain solution B; (3) Transfer the AC@GPs composite material obtained in step (1) and solution B obtained in step (2) to a hydrothermal reactor together, and carry out hydrothermal reaction at 140 °C for 16 h to enable the chemical epitaxial growth of TiO2 on the surface of the AC coating; (4) After the hydrothermal reaction is completed, take out the sample, wash it alternately with deionized water and ethanol 6 times (wash the sample with deionized water for the 1st, 3rd, and 5th times, and wash the sample with absolute ethanol for the 2nd, 4th, and 6th times), dry the washed sample in an oven at 80 °C, and then calcine it at 600 °C for 2 h under an argon atmosphere to obtain the nano-TiO2@AC@GPs electrocatalytic anode material.

[0038] Comparative Example 1 (1) Take a high-purity graphite sheet (GPs) with a thickness of 2 mm, and ultrasonically clean it with acetone for later use; (2) Weigh 0.2 g of CTAB and dissolve it in a 50 mL methanol / deionized water (the volume ratio of methanol to deionized water is 2:1) mixed solution to obtain solution A; add 10 mL of 0.05 mol / L Ti(SO4)2 solution to solution A and stir evenly to obtain solution B; (3) Transfer the cleaned high-purity graphite sheet GPs in step (1) and solution B obtained in step (2) to a hydrothermal reactor together, and carry out hydrothermal reaction at 160 °C for 12 h; (4) After the hydrothermal reaction is completed, take out the sample, wash it alternately with deionized water and ethanol 6 times (wash the sample with deionized water for the 1st, 3rd, and 5th times, and wash the sample with absolute ethanol for the 2nd, 4th, and 6th times), dry the washed sample in an oven at 80 °C, and then calcine it at 600 °C for 2 h under an argon atmosphere to obtain the TiO2@GPs electrocatalytic anode material.

[0039] Figure 1(a) is the SEM image of the original graphite sheet used in Example 1, and Figure 1(b) is the SEM image of the AC@GPs composite material obtained after depositing the amorphous carbon layer in step (1) of Example 1. By comparison, it can be seen that an amorphous carbon coating can be formed on the surface of the graphite sheet through chemical vapor deposition.

[0040] Figure 2(a) is the Raman spectrum of the original graphite sheet used in Example 1, and Figure 2(b) is the Raman spectrum of the AC@GPs composite material obtained in step (1) of Example 1. By comparison, it can be seen that, compared with the original graphite sheet, the intensity of the D peak (near 1350 cm⁻¹) is significantly enhanced (compared with the original graphite sheet, the peak height at 1350 cm⁻¹ increases significantly), the intensity of the G peak (near 1580 cm⁻¹) changes relatively little, and the ID / IG ratio increases, indicating that a defective carbon coating layer is introduced on the graphite surface.

[0041] Figure 3It is the X-ray diffraction (XRD) pattern of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1. In the figure, the 25.00° peak (intensity 12141.6666) is close to the 25.3° peak of anatase titanium dioxide, and the 48.00° peak (intensity 6191.6666) is close to the 48.1° peak of anatase titanium dioxide, but the peak positions are slightly shifted. Through XRD analysis, it can be judged that titanium dioxide exists in the prepared nano-TiO2@AC@GPs electrocatalytic anode material. The peak position shift may be due to the broadening of the peak caused by the small size of TiO2 nanoparticles or the interaction with graphite. Since the surface of graphite is completely covered by anatase titanium dioxide, no diffraction peaks related to graphite flakes are detected.

[0042] The photocurrent curve of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 was tested using the time-current curve in an electrochemical workstation. The test solution was 1 g / L sodium sulfate solution, and the results are as Figure 4 shown. The peak heights and shapes of multiple cycles in the curve are basically the same, indicating that the photoelectric response of the material is stable and suitable for long-term photoelectric applications. After turning on the light, the current quickly rises to the steady state, indicating that the composite material can effectively generate electron-hole pairs under illumination. After shading, the current decays to the dark current. The high photocurrent and low dark current indicate that the material has efficient photogenerated charge separation ability and stable photoelectric response. The current has good repeatability and low dark current, making it suitable for applications such as photocatalytic water splitting and pollutant degradation.

[0043] Figure 5 is the SEM image of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 at different magnifications. Among them, the magnifications of Figure 5(a), Figure 5(b), and Figure 5(c) are 30 times, 20000 times, and 100000 times respectively. It can be seen from Figure 5(c) that TiO2 grows uniformly in small particle form on the surface of the AC layer of the AC@GPs composite material. The TiO2 particles are of uniform size, and the average diameter is about 25 - 50 nm.

[0044] Figure 6 is the SEM image of the TiO2@GPs electrocatalytic anode material prepared in Comparative Example 1. It can be seen from Figure 6 that in Comparative Example 1, only part of the graphite flakes are covered with TiO2, and the combination of TiO2 and GPs is loose, resulting in poor material stability. Comparing Figure 5 and Figure 6 it can be known that depositing an amorphous carbon layer as an intermediate layer on the surface of graphite flakes can enhance the nucleation and growth ability of subsequent TiO2, enable TiO2 to uniformly cover the surface of AC@GPs, improve the overall interface bonding ability of the material, form a stable TiO2@AC@GPs material, and enhance the electrocatalytic activity and stability of the TiO2@AC@GPs material.

[0045] Prepare a series of rhodamine B standard solutions with different concentrations, measure the absorbance of the rhodamine B standard solutions with different concentrations at 554 nm, make a standard curve of absorbance against concentration, and obtain the standard curve equation of the absorbance of the rhodamine B solution against concentration. Use a stainless steel mesh (size 20*20*2 mm) as the cathode and the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 as the anode (size 20*20*2 mm), and test the electrocatalytic degradation effect of the TiO2@AC@GPs electrocatalytic anode material on rhodamine B under a constant current. The volume of the rhodamine B solution is 200 mL, the initial concentration is 20 mg / L, the electrolyte is 1 g / L sodium sulfate, and the degradation time is 120 min. Measure the absorbance of the rhodamine B solution at time t at 554 nm, and substitute the absorbance into the standard curve equation to calculate the concentration C of rhodamine B in the solution at time t t , and calculate the degradation rate with D%=(C0 - C t ) / C0×100%, where D% represents the degradation rate and C0 represents the initial concentration of the rhodamine B solution. Plot the degradation rate against the degradation time. Test the degradation rates of the original graphite sheet and the AC@GPs composite material obtained in step (1) of Example 1 at different degradation times in the same way, and plot the degradation rate against the degradation time. The results are as Figure 7 shown. It can be seen that the degradation rate of the nano-TiO2@AC@GPs electrocatalytic anode material on the organic dye rhodamine B is much greater than that of the original graphite sheet GPs and the AC@GPs composite material

[0046] Figure 8 is the curve of the degradation rate of the TiO2@GPs material prepared in Comparative Example 1 on the organic dye rhodamine B changing with the degradation time Figure 7 and Figure 8 By comparison, it can be known that the electrocatalytic degradation effect of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 on rhodamine B under a constant current is also much greater than that of the TiO2@GPs material prepared in Comparative Example 1, indicating that the amorphous carbon coating is beneficial to enhancing the degradation effect of the TiO2@AC@GPs electrocatalytic anode material on rhodamine B

[0047] In the above degradation rate test experiment, according to the C t values at different degradation times, calculate ln(C0 / C t ), plot ln(C0 / C t ) against the degradation time, and obtain the first-order kinetic curves and equations for the degradation of rhodamine B by the original graphite sheet, the AC@GPs composite material obtained in step (1) of Example 1, and the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1, as Figure 9As shown, it can be seen that the rate constant of the first-order kinetic equation for the degradation of Rhodamine B by the nano-TiO2@AC@GPs electrocatalytic anode material is 6 times that of the original graphite sheet.

[0048] Figure 10 Figure 4 is the electrocatalytic degradation cycle experiment diagram of the nano-TiO2@AC@GPs electrocatalytic anode material prepared in Example 1 for the organic dye Rhodamine B for 14 times and 1680 min. It can be seen that the nano-TiO2@AC@GPs electrocatalytic anode material has excellent cycle stability and corrosion resistance. After 14 times and 1680 min of electrocatalytic cycle experiments, the electrocatalytic effect remains within a reasonable fluctuation range, and the electrocatalytic effect is stable and reliable.

[0049] The above are only examples of the present invention, and it does not impose any form of limitation on the present invention. The present invention can also have other forms of embodiments according to the above structure and function, which will not be listed one by one. Therefore, any person skilled in the art, without departing from the scope of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A preparation method of a nano-TiO2@AC@GPs electrocatalytic anode material, characterized in that, It includes the following steps: (1) Using methane as a carbon source, depositing an amorphous carbon layer AC on the surface of graphite flakes GPs by chemical vapor deposition to obtain an AC@GPs composite material; (2) Dissolving cetyltrimethylammonium bromide in a mixed solution of methanol and deionized water to obtain solution A, with the concentration of cetyltrimethylammonium bromide in solution A being 2 - 4 g / L; adding a titanium sulfate solution to solution A and stirring evenly to obtain solution B; (3) Transferring the AC@GPs composite material obtained in step (1) and solution B obtained in step (2) together into a hydrothermal reaction kettle, carrying out a hydrothermal reaction at 120 - 200 °C to enable the epitaxial growth of TiO2 nanomaterials on the AC coating surface of the AC@GPs composite material; (4) After the hydrothermal reaction ends, taking out the sample, successively carrying out washing, drying, and high-temperature calcination treatments to obtain a nano-TiO2@AC@GPs electrocatalytic anode material.

2. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, The process parameters of the chemical vapor deposition in step (1) are: deposition temperature 850 - 1100 °C, reaction time 30 - 60 min, and the protective atmosphere is argon or nitrogen.

3. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, In the mixed solution of step (2), the volume ratio of methanol to deionized water is 1:1 - 3:

1.

4. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, The Ti in solution B of step (2) 4+ is controlled at a concentration of 0.0045 to 0.0083 mol / L.

5. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, In step (3), the hydrothermal reaction time is 6 - 24 h.

6. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, wherein, In step (4), the sample is successively washed 6 times alternately with deionized water and ethanol, the washed sample is dried in an oven at 80 °C, the high-temperature calcination is carried out under an inert gas, the calcination temperature is 300 - 600 °C, and the calcination time is 1 - 4 h.

7. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, In the prepared nano-TiO2@AC@GPs electrocatalytic anode material, TiO2 grows evenly in small particle form on the surface of AC@GPs, the TiO2 particle sizes are uniform, and the average diameter is 25 - 50 nm.

8. The preparation method of the nano-TiO2@AC@GPs electrocatalytic anode material according to claim 1, characterized in that, The prepared nano-TiO2@AC@GPs electrocatalytic anode material is used for electrocatalytic degradation of organic wastewater.

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