Preparation method of carbon modified foam bimetallic alloy for EF cathode

Abstract

The invention discloses a preparation method of a carbon modified foam bimetallic alloy for an EF cathode, which comprises the following steps: after melting glucose, uniformly infiltrating the foam bimetallic alloy in a glucose solution, taking out, cooling to room temperature, heating in a muffle furnace, dehydrating at a constant temperature, naturally cooling, taking out, heating to 800 DEG C in the muffle furnace, keeping for 2 hours, and cooling to room temperature to obtain the carbon modified foam bimetallic alloy for the EF cathode. And cooling to room temperature and then taking out to obtain the carbon modified foam bimetallic alloy for the EF cathode. According to the prepared carbon modified foam bimetallic alloy of the EF cathode, the homogeneous EF problem is solved, and meanwhile the heterogeneous EF degradation effect is improved. According to the invention, carbon is loaded on a foam bimetallic alloy by adopting a high-temperature carbonization method, the surface topography characteristics of the modified foam bimetallic alloy are observed by utilizing a field emission electron microscope (SEM), and good degradation efficiency of the modified foam bimetallic alloy is proved by degrading rhodamine B (RhB) through an EF system.

Description

Technical Field

[0001] The invention relates to the technical field of electrochemical materials, and specifically discloses a method for preparing a carbon-modified foam bimetallic alloy for an EF cathode. Background Art

[0002] Fenton oxidation for organic removal based on added H2O2 and Fe catalyst 2+ The generated hydroxyl radicals (·OH) with strong oxidizing ability can achieve the degradation and even mineralization of organic pollutants. H2O2 with strong corrosive and oxidizing properties has serious transportation and storage safety problems, which brings higher processing costs and operational risks to the Fenton oxidation removal of organic matter. In recent years, in order to further develop Fenton oxidation, electro-Fenton technology has emerged. The basic principle of the electro-Fenton reaction is that O2 is reduced to H2O2 at the cathode and reacts with Fe 2+ The reaction generates ·OH with strong oxidizing properties, thus achieving oxidative degradation of pollutants.

[0003] Electro-Fenton (EF) oxidation is carried out by directly adding Fe 2+ It reacts with H2O2 produced at the cathode to generate ·OH, thereby promoting the degradation of polluted wastewater. However, under neutral and alkaline conditions, the Fe 3+ Iron sludge precipitation is inevitable, which makes Fe 2+ The concentration decreases, and the H2O generated on the cathode material surface 2难以 The effective conversion into ·OH makes EF unsuitable for wastewater treatment in a wide pH range (usually the most suitable pH is ≈ 3). At the same time, the homogeneous EF reaction produces secondary pollution (iron sludge), which further causes problems such as difficulty in catalyst recycling.

[0004] Therefore, developing a heterogeneous EF cathode material with a wide pH range, especially suitable for near-neutral or alkaline conditions, and capable of efficiently producing OH in situ on the electrode surface is beneficial to the promotion and application of EF technology for wastewater treatment. Summary of the invention

[0005] In view of the above shortcomings, in order to solve the problems of narrow pH application range, secondary pollution, difficulty in catalyst recycling and reuse in homogeneous EF, low catalytic efficiency of heterogeneous electro-Fenton cathode materials, etc., the present invention develops a carbon-modified foam bimetallic alloy for EF cathode, which solves the problems of homogeneous EF and improves the degradation effect of heterogeneous EF. The invention uses a high-temperature carbonization method to load carbon on the foam bimetallic alloy, uses a field emission electron microscope (SEM) to observe the surface morphology of the modified foam bimetallic, and confirms its good degradation efficiency by degrading rhodamine B (RhB) through the EF system.

[0006] The present invention is achieved by the following technical means:

[0007] The present invention first discloses a method for preparing a carbon-modified foam bimetallic alloy for an EF cathode, comprising:

[0008] (1) uniformly mixing the foam bimetallic alloy and glucose, taking out and cooling to room temperature to obtain a pretreated foam bimetallic alloy;

[0009] (2) placing the pretreated foam bimetallic alloy in a muffle furnace, heating it, and then dehydrating it at a constant temperature, and then taking it out after natural cooling to obtain a dehydrated foam bimetallic alloy;

[0010] (3) The dehydrated foam bimetallic alloy is placed in a muffle furnace and heated and maintained, and then taken out after cooling to room temperature, thereby obtaining a carbon-modified foam bimetallic alloy of an EF cathode.

[0011] Furthermore, the step (1) of uniformly mixing the foam bimetallic alloy with glucose comprises:

[0012] Place the foamed bimetallic alloy in the glucose solution and soak it evenly; or

[0013] The heated foam bimetallic alloy is dipped into glucose and heated again to melt.

[0014] Furthermore, the glucose solution is obtained by heating and melting glucose.

[0015] Furthermore, the heating in the muffle furnace in step (2) includes: heating from room temperature to 250° C. at a rate of 2° C. / min.

[0016] Furthermore, the constant temperature dehydration in step (2) includes: constant temperature dehydration at 250° C. for 20 hours.

[0017] Furthermore, the heating in the muffle furnace in step (3) includes: heating from room temperature to 800° C. at a rate of 2° C. / min.

[0018] Furthermore, the maintaining after heating in step (3) includes: maintaining at 800° C. for 2 hours.

[0019] The present invention also discloses a carbon-modified foam bimetallic alloy of an EF cathode prepared according to any of the above-mentioned preparation methods.

[0020] The invention also discloses an application of the carbon-modified foam bimetallic alloy according to the EF cathode in the degradation of organic dye wastewater.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention solves the problems of difficulty in recycling homogeneous electro-Fenton catalyst, secondary pollution of iron mud, additional addition of H2O2, and narrow pH application range.

[0023] 2. The present invention improves the processing efficiency of the foamed iron-nickel bimetallic alloy as a heterogeneous EF cathode and expands the pH application range of the heterogeneous EF system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a foam bimetallic alloy (Fe:Ni=5:5) without carbon modification, where a is the SEM image of the unmodified foam bimetallic alloy; b is the mapping image of the unmodified foam bimetallic alloy.

[0025] Figure 2 This is the mapping diagram of the carbon-modified foam bimetallic alloy, which shows the contents of nickel (Ni), oxygen (O), and iron (Fe).

[0026] Figure 3 This is the mapping diagram of carbon-modified foam bimetallic alloy, which shows the contents of four elements: oxygen (O), iron (Fe), nickel (Ni), and carbon (C).

[0027] Figure 4 Figure 2 shows the degradation performance of RhB used as EF cathode before and after modification of the bimetallic alloy. DETAILED DESCRIPTION

[0028] The content of the present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only to enable those skilled in the art to better understand and thus implement the content of the present invention, rather than implying any limitation on the scope of the present invention.

[0029] As used herein, the term “including” and variations thereof are to be interpreted as open-ended terms meaning “including, but not limited to.” The term “based on” is to be interpreted as “based, at least in part, on.” The terms “one embodiment” and “an embodiment” are to be interpreted as “at least one embodiment.”

[0030] Example 1

[0031] A method for preparing a carbon-modified foam bimetallic alloy for an EF cathode comprises the following steps:

[0032] (1) Melting glucose on an electric furnace with a power of 220V, and immersing the foam bimetallic alloy in the glucose melt, taking it out after being evenly infiltrated, and cooling it to room temperature to obtain a pretreated foam bimetallic alloy;

[0033] (2) placing the pretreated foam bimetallic alloy in a muffle furnace, raising the temperature from room temperature to 250° C. at a rate of 2° C. / min, dehydrating at 250° C. for 20 h, and taking it out after natural cooling to obtain a dehydrated foam bimetallic alloy;

[0034] (3) The dehydrated foam bimetallic alloy was placed in a muffle furnace, the temperature was raised from room temperature to 800°C at a rate of 2°C / min, maintained at 800°C for 2 h, and taken out after being cooled to room temperature to obtain a carbon-modified foam bimetallic alloy material.

[0035] Example 2

[0036] A method for preparing a carbon-modified foam bimetallic alloy for an EF cathode comprises the following steps:

[0037] (1) heating the foam bimetal, dipping it in glucose / sucrose powder, and heating it again to melt it, so that it is evenly soaked, taking it out, and cooling it to room temperature to obtain a pretreated foam bimetal alloy;

[0038] (2) placing the pretreated foam bimetallic alloy in a muffle furnace, raising the temperature from room temperature to 250° C. at a rate of 2° C. / min, dehydrating at 250° C. for 20 h, and taking it out after natural cooling to obtain a dehydrated foam bimetallic alloy;

[0039] (3) The dehydrated foam bimetallic alloy was placed in a muffle furnace, the temperature was raised from room temperature to 800°C at a rate of 2°C / min, maintained at 800°C for 2 h, and taken out after being cooled to room temperature to obtain a carbon-modified foam bimetallic alloy material.

[0040] Comparative Example 1

[0041] Compared with Example 1, the glucose infiltration pretreatment in step (1) is omitted in this comparative example. The details are as follows:

[0042] A method for preparing a carbon-modified foam bimetallic alloy for an EF cathode comprises the following steps:

[0043] (1) placing the foamed bimetallic alloy in a muffle furnace, heating the temperature from room temperature to 250° C. at a rate of 2° C. / min, dehydrating the alloy at a constant temperature of 250° C. for 20 h, and taking the alloy out after natural cooling to obtain a dehydrated foamed bimetallic alloy;

[0044] (2) The dehydrated foam bimetallic alloy was placed in a muffle furnace, the temperature was raised from room temperature to 800°C at a rate of 2°C / min, maintained at 800°C for 2 h, and taken out after being cooled to room temperature to obtain an uncarbon-modified foam bimetallic alloy material.

[0045] Test Example 1

[0046] Compare the samples obtained in Example 1 and Comparative Example 1

[0047] pass Figure 1 to Figure 3The SEM images and mapping images in the figure analyze the changes in the surface structure and morphology of the foam bimetal before and after carbon modification. It can be seen that the iron-nickel bimetallic alloy before modification was oxidized in the high-temperature muffle furnace, and the oxygen content increased significantly; the pore structure of the modified foam iron-nickel bimetallic alloy is smaller and denser than before modification, but due to the oxidation and volatilization of high-temperature carbon, the oxygen content in the bimetallic alloy is less, and the impurities in iron and nickel have also been removed to a certain extent, and the alloy system has formed a more homogeneous iron, nickel, and oxygen body.

[0048] Application Example 1

[0049] The foam bimetallic before and after carbon modification was used as EF cathode to study the degradation performance of the electrode for organic dye wastewater. Here, RhB was taken as a representative dye and the simulated wastewater component was RhB (10 mg / L).

[0050] 0.35 mol / L Na2SO4 was used as the electrolyte; the foam bimetallic alloy (10mm*20mm*1.0mm) before and after modification was used as the EF cathode, and the platinum sheet of the same size was used as the anode; the electrode spacing was 2cm; the cathode surface oxygenation rate was 0.1L / min; the DC voltage was 15V and the reaction was carried out for 30min. 1ml was taken as the sample to be tested at the reaction time of 0min, 15min, and 30min, and its absorbance was measured using a UV-visible spectrophotometer at the optimal absorption wavelength of 552nm.

[0051] The experimental results are as follows Figure 4 As shown:

[0052] according to Figure 4 The degradation results of RhB show that the degradation rate of RhB in 30min is 97% after modification with Fe-Ni bimetallic as EF cathode, which is about 25% higher than that before modification (77%). The modification has achieved good results.

[0053] In addition, the experiment observed that there was no cathode surface peeling and the water body did not turn yellow or green during the reaction, indicating that the performance of the cathode material was stable during the reaction and there was no leaching of iron and nickel elements.

[0054] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing a carbon-modified foam bimetallic alloy for an EF cathode, comprising: (1) uniformly mixing the foam bimetallic alloy and glucose, taking out and cooling to room temperature to obtain a pretreated foam bimetallic alloy; (2) placing the pretreated foam bimetallic alloy in a muffle furnace, heating it, and then dehydrating it at a constant temperature, and then taking it out after natural cooling to obtain a dehydrated foam bimetallic alloy; (3) The dehydrated foam bimetallic alloy is placed in a muffle furnace and heated and maintained, and then taken out after cooling to room temperature, thereby obtaining a carbon-modified foam bimetallic alloy of an EF cathode.

2. The preparation method according to claim 1, wherein: The step (1) of uniformly mixing the foam bimetallic alloy with glucose comprises: Place the foamed bimetallic alloy in the glucose solution and soak it evenly; or The heated foam bimetallic alloy is dipped into glucose and heated again to melt.

3. The preparation method according to claim 2, wherein: The glucose solution is prepared by heating and melting glucose.

4. The preparation method according to claim 1, wherein: The heating in the muffle furnace in step (2) comprises: From room temperature to 250°C at 2°C / min; The constant temperature dehydration in step (2) comprises: Dehydrate at 250℃ for 20h.

5. The preparation method according to claim 1, wherein: The heating in the muffle furnace in step (3) comprises: From room temperature to 800°C at 2°C / min; The step (3) of maintaining the temperature after heating includes: Maintain at 800°C for 2h.

6. A carbon-modified foam bimetallic alloy for EF cathode prepared according to the preparation method of any one of claims 1 to 5.

7. Use of the carbon-modified foam bimetallic alloy of the EF cathode according to claim 6 in the degradation of organic dye wastewater.

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