Method for preparing catalyst with piezoelectric properties using copper slag and its application

Abstract

The invention discloses a method for preparing a catalyst with piezoelectric properties by using copper slag. The method is characterized by comprising the following steps: crushing and screening dried copper slag, calcining the slag at 450-550°C, mixing the calcined copper slag with Bi2O3, adding anhydrous ethanol, grinding and mixing, calcining the slag at 550-650°C, mixing the calcined product, manganese sulfate monohydrate and water, dropping a potassium permanganate solution into the mixture, heating the mixture in a water bath at 45-55°C, separating the reaction product into a solid and a liquid, washing, drying and grinding the solid to obtain the catalyst with piezoelectric properties. The catalyst BSFM prepared by the method has the advantages of high specific surface area, multiple reactive sites, good piezoelectric properties, high metal atom utilization rate, stable structure and the like, can be widely used for degrading organic pollutants and oxidatively adsorbing the toxic element As(III), and has good degradation and adsorption removal effects. The method realizes resource utilization of solid waste and has great application prospects in the field of environmental catalysis.

Description

Technical Field

[0001] The present invention belongs to the technical field of secondary utilization of solid waste, and particularly relates to a method for preparing a catalyst with piezoelectric properties by utilizing copper slag and its application in removing organic matter and arsenic. Background Art

[0002] Arsenic (As) is a highly toxic metalloid element widely distributed in the environment. Irrigation with arsenic-containing groundwater and the use of arsenic-containing pesticides have led to severe soil contamination. As can cause serious health effects, including lung, bladder, and kidney cancers, as well as numerous neurological, renal, hematologic, and respiratory diseases. Arsenic exists primarily in nature as As(III) and As(V), with As(III) exhibiting greater toxicity, solubility, and mobility than As(V). Typical background concentrations of arsenic in soil do not exceed 100 mg / kg, and in freshwater no more than 10 μg / L. Currently, the three most common tetracycline antibiotics are chlortetracycline (CTC), oxytetracycline (OTC), and tetracycline (TC). These antibiotics are widely used in livestock and aquaculture. Because they are not fully absorbed and metabolized by animals, approximately 40% to 90% of the active ingredient is ultimately excreted into the environment as the original drug or isomers in livestock and poultry feces and urine, impacting both the environment and human health. Combined contamination of arsenic and organic matter occurs not only in aquatic environments but is also common in soil. Due to the widespread use of organic fertilizers and arsenic contamination, antibiotic-contaminated feces may be applied to arsenic-contaminated soils, leading to combined contamination of arsenic and antibiotics in the soil. The coexistence of arsenic and TCs is widespread, particularly in agricultural soils.

[0003] Developed removal technologies for arsenic and organic matter pollution include adsorption, chemical precipitation, oxidation, ion exchange, and photocatalysis. The most notable feature of advanced oxidation processes is their ability to generate hydroxyl radicals (OH) through oxidation reactions with oxidants. Due to their high reactivity, hydroxyl radicals react with organic pollutants in wastewater to degrade them into carbon dioxide and water, effectively degrading the pollutants. Various oxidation processes, such as chemical oxidants (chlorine, permanganate, etc.) and advanced oxidation processes (AOPs) (such as UV / H2O2, Fenton reaction, UV / nitrite, and UV / persulfate) have been widely used for As(III) pre-oxidation or oxidative degradation of organic matter. However, conventional chemical oxidants (chlorine, chloramines, and ozone) can produce toxic byproducts such as trihalomethanes, nitrosamines, and bromate; the Fenton process is highly pH-dependent and prone to sludge generation; and the long treatment cycle and high cost of UV irradiation limit its practical application. The emerging piezoelectric catalytic effect has attracted considerable attention. When external strain is applied to a piezoelectric material, a polarization electric field appears on the surface of the piezoelectric material, causing the centers of positive and negative charges to shift. This internal pressure potential maintained with stress can induce the separation of electron-hole pairs generated by the piezoelectric and trigger redox reactions.

[0004] Bismuth-based composite oxides have attracted much attention due to their excellent photooxidation ability and efficient photocatalytic degradation of organic pollutants and water oxidation performance. However, the relatively low conduction band level limits their further application in photocatalytic hydrogen evolution and the entire water splitting process. 25 FeO 40 Bismuth is a bismuth-based semiconductor material that responds to visible light. It has a narrow band gap and exhibits excellent electrical, magnetic and light absorption properties, making it have great application potential in the fields of multiferroic materials and photocatalytic materials. However, there is a problem of high recombination rate of photogenerated electrons and holes, which affects the catalytic performance and practical application of the catalyst. 12 SiO 20 It has good carrier mobility, narrow band gap, and excellent photoelectric, acousto-optic, and dielectric properties. It should be an ideal photocatalytic material. However, the synthesized Bi 12 SiO 20 The particle size is always at the micron level, resulting in a very small specific surface area, which greatly restricts the photocatalytic performance.

[0005] Copper slag is a solid waste product formed during the smelting of copper alloys. It is primarily composed of Fe2O3, SiO2, Al2O3, and CaO. The overall utilization rate of copper slag is low, and most of it is still stored in piles, occupying significant land and causing environmental pollution. Copper slag contains a large amount of ferrous silicate, which exhibits gelling properties after alkaline activation. Furthermore, copper slag contains a large amount of magnetite, which imparts magnetic properties to the product, facilitating separation and recovery with adsorbents. Summary of the Invention

[0006] The present invention provides a method for preparing a catalyst with piezoelectric properties using copper slag. The catalyst prepared by the present invention has a high specific surface area, multiple reaction active sites, good piezoelectric properties, high metal atom utilization rate, and a stable structure, and has great application value and prospects. In addition, the method of the present invention has a simple process, convenient operation, readily available raw materials, low cost, and high yield.

[0007] The method of preparing a catalyst having piezoelectric properties using copper slag according to the present invention is as follows:

[0008] 1. Dry the copper slag at a constant temperature of 60°C for 36-48 hours, ball-mill for 2-3 hours, and then sieve through a 180-mesh sieve to obtain copper slag powder. Place the copper slag powder in a crucible and calcine it in a muffle furnace at 450-550°C for 3 hours. Grind the copper slag powder.

[0009] 2. Grind the calcined copper slag powder, Bi2O3, and anhydrous ethanol in a mortar for 0.5-1h. The mass ratio of calcined copper slag to Bi2O3 is 1:0.3-2. Pour the mixture into a nickel crucible, and place the nickel crucible in a muffle furnace and calcine at 550-650℃ for 1h.

[0010] 3. Mix manganese sulfate monohydrate, the calcined product of step 2, and water to obtain a mixed solution, add potassium permanganate solution dropwise to the mixed solution, and finally heat in a water bath at 45-55° C. for 12 hours. The reaction product is separated into solid and liquid, and the solid is washed, dried, and ground to obtain a catalyst BSFM with piezoelectric properties, wherein the mass ratio of the calcined product to manganese sulfate monohydrate is 1.7-8.5:1, and the mass ratio of the calcined product to potassium permanganate is 2.7-14:1.

[0011] Another object of the present invention is to use the catalyst prepared by the above method in the catalytic degradation of antibiotics and arsenic.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] (1) The present invention uses industrial solid waste copper slag as raw material, and after a simple roasting treatment, solid phase synthesis with Bi2O3 is used to prepare the catalyst carrier. Although the solid phase reaction method may cause agglomeration between powder particles and the generation of impurities during the high temperature heat treatment process, it has the advantages of simple process and low cost, and is the main method most likely to obtain industrial application.

[0014] (2) The present invention adopts a simple hydrothermal synthesis to successfully load amorphous MnO2 on the surface of the catalyst support, and prepares the catalyst BSFM with the advantages of high specific surface area, multiple reaction active sites, good piezoelectric performance, high metal atom utilization rate, and stable structure; the preparation method is simple to operate, has a high yield, can significantly increase the specific surface area of ​​the catalyst, and improve the catalytic efficiency of the catalyst; a heterojunction is constructed between the support and MnO2, which successfully improves the charge mobility. While MnO2 plays a role, it provides high surface defects and uniform catalytic active sites; at the same time, the preparation method of the present invention also has the advantages of simple process, convenient operation, easy availability of raw materials, low cost, easy to realize industrial production, and has great application prospects, especially in the field of environmental catalysis;

[0015] (3) The catalyst BSFM prepared by the present invention is mixed with tetracycline hydrochloride wastewater and stirred, and can effectively degrade organic pollutants under constant temperature oscillation or ultrasonic conditions, which has the advantages of simple process, convenient operation, low cost, high treatment efficiency, and good degradation effect; and is evenly mixed with wastewater containing the highly toxic element As(III), and can catalytically oxidize the toxic element As(III) into less toxic As(V). The catalyst BSFM oxidizes and adsorbs As(III) and As(V) under constant temperature oscillation or ultrasonic conditions, effectively reducing the toxicity of the wastewater; it has good degradation and adsorption effects for solving wastewater containing organic matter and arsenic in life, and has good development prospects in the field of treating highly toxic organic wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The XRD patterns of the products at different stages during the preparation of the catalyst in Example 1 and the amorphous manganese dioxide catalyst in Comparative Example 4 are shown;

[0017] Figure 2 is the SEM image of the catalyst support BSFO;

[0018] Figure 3 is the SEM image of catalyst BSFM;

[0019] Figure 4 XRD patterns of bismuth silicate catalyst BSO (pure), bismuth ferrite catalyst BFO (pure), bismuth silicate and bismuth ferrite composite catalyst BSFO (pure), catalyst support BSFO of Example 1, and catalyst BSFM of Example 1;

[0020] Figure 5 is the SEM image of the amorphous manganese dioxide catalyst;

[0021] Figure 6 This is a time-degradation efficiency diagram when the catalysts in Example 1 and Comparative Examples 1-4 degrade tetracycline hydrochloride solution under oscillation conditions;

[0022] Figure 7 This is a time-degradation efficiency diagram when the catalysts in Example 1 and Comparative Examples 1-4 degrade tetracycline hydrochloride solution under ultrasonic conditions;

[0023] Figure 8 This is a fitting diagram of the degradation rate constant when the catalysts in Example 1 and Comparative Examples 1-4 degrade tetracycline hydrochloride solution under ultrasonic conditions;

[0024] Figure 9 This is a time-degradation efficiency diagram of the catalysts in Example 1 and Comparative Examples 1-4 when degrading As(III) under oscillation conditions;

[0025] Figure 10 This is a time-degradation efficiency diagram of the catalysts in Example 1 and Comparative Examples 1-4 when degrading As(III) under ultrasonic conditions;

[0026] Figure 11 This is a fitting diagram of the degradation rate constant when the catalysts in Example 1 and Comparative Examples 1-4 degrade As(III) under ultrasonic conditions. DETAILED DESCRIPTION

[0027] The present invention is further described below by way of examples, but these examples do not limit the scope of protection of the present invention. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional reagents sold on the market unless otherwise specified.

[0028] The copper slag used in the following examples mainly contains Fe2O3 73.79%, SiO2 10.47%, Al2O3 1.32%, CaO 3.02%, and ZnO 3.78%;

[0029] Example 1: Preparation of a catalyst with piezoelectric properties using copper slag

[0030] 1. Dry the copper slag at 60℃ for 40h, ball mill for 2h and pass through 180 mesh sieve to obtain copper slag powder. Place the copper slag powder in a crucible and calcine it in a muffle furnace at 500℃ for 3h. Grind it to obtain dark reddish brown copper slag powder. The XRD pattern of the calcined copper slag is shown in Figure 1 From the figure, we can see that the main characteristic peaks of the crystal phase substances are Fe2O3 and SiO2, and the characteristic peaks of Fe2O3 appear around 2θ=25°~45° and 2θ=50°~60°, indicating that CS contains a large amount of Fe2O3;

[0031] 2. 1.4 g of calcined copper slag powder and 1.165 g of Bi2O3 were placed in a mortar, and anhydrous ethanol was added and ground for 0.5 hours to obtain a uniform mixed powder. The mixed powder was placed in a nickel crucible and calcined in a muffle furnace at 600°C for 1 hour. After natural cooling, the catalyst support BSFO was obtained by grinding with a mortar. The SEM image of the catalyst support BSFO is shown in FIG. Figure 2 ,It can be seen from the figure that the catalyst carrier has a block and sheet structure;

[0032] 3. Take 0.14g of manganese sulfate monohydrate and 0.3g of catalyst support, dissolve them in 50mL of deionized water, record it as solution A, take 0.086g of potassium permanganate and dissolve it in 50mL of deionized water to prepare potassium permanganate solution, add the potassium permanganate solution dropwise into solution A and mix well; put the mixed solution into a constant temperature water bath, keep it warm at 50℃ for 12h, let it cool naturally, filter it, rinse the solid with water 5 times, dry it at 60℃ for 12h, and grind it in a mortar to obtain catalyst BSFM. The SEM image of catalyst BSFM is shown in Figure 3 ,It can be seen from the figure that MnO2 is uniformly loaded on the catalyst support and forms a layered cross-linked network structure;

[0033] The XRD patterns of the catalyst support BSFO and the catalyst BSFM are shown in Figure 1 From the figure, we can see that both the catalyst carrier BSFO and the catalyst BSFM have strong Bi 25 FeO 40 (JCPDSNo.46-0416) and Bi 12 SiO 20 ((JCPDS No.37-0485) diffraction peaks, indicating that the product contains both bismuth silicate and bismuth ferrite.

[0034] Example 2: The method of this example is the same as that of Example 1, except that 0.035 g of manganese sulfate monohydrate and 0.3 g of the catalyst support are dissolved in deionized water, and 0.0215 g of potassium permanganate is dissolved in 50 mL of deionized water.

[0035] Example 3: The method of this example is the same as that of Example 1, except that 0.07 g of manganese sulfate monohydrate and 0.3 g of the catalyst support are dissolved in deionized water, and 0.043 g of potassium permanganate is dissolved in 50 mL of deionized water.

[0036] Example 4: The method of this example is the same as that of Example 1, except that 0.105 g of manganese sulfate monohydrate and 0.3 g of the catalyst support are dissolved in deionized water, and 0.0645 g of potassium permanganate is dissolved in 50 mL of deionized water.

[0037] Example 5: The method of this example is the same as that of Example 1, except that 0.578 g of manganese sulfate monohydrate and 1 g of the catalyst support are dissolved in deionized water, and 0.36 g of potassium permanganate is dissolved in 50 mL of deionized water.

[0038] Comparative Example 1: Preparation of bismuth silicate catalyst

[0039] Take 0.8g of silicon dioxide and 2.33g of bismuth oxide, put them into a mortar and add anhydrous ethanol for grinding for 0.5 hours to obtain a uniform mixed powder, put it into a nickel crucible, place it in a muffle furnace and roast it at 600℃ for 1 hour. After natural cooling, grind it in a mortar to obtain bismuth silicate catalyst BSO (pure), and its XRD pattern is shown in Figure 4 From the figure, we can see that 24.82°, 27.88°, 30.53°, 33.10°, 52.67°, 55.97° and 62.24° correspond to the (220), (310), (222), (321), (530), (611) and (631) planes of BSO (pure), respectively, indicating that pure bismuth silicate Bi 12 SiO 20 Successfully synthesized.

[0040] Comparative Example 2: Preparation of bismuth ferrite catalyst

[0041] Take 0.8g of ferric oxide and 2.33g of bismuth oxide, put them into a mortar and add anhydrous ethanol for grinding for 0.5 hours to obtain a uniform mixed powder, put it into a nickel crucible, place it in a muffle furnace and roast it at 600℃ for 1 hour. After natural cooling, grind it in a mortar to obtain bismuth ferrite catalyst BFO (pure), and its XRD pattern is shown in Figure 2. Figure 4 From the figure (pure), we can see that 24.70°, 27.68°, 30.29°, 32.98°, 53.99°, 55.61° and 61.76° correspond to the (220), (310), (222), (321), (600), (611) and (631) planes of BFO, respectively, indicating that pure bismuth silicate Bi 25 FeO 40 Successfully synthesized.

[0042] Comparative Example 3: Preparation of bismuth silicate and bismuth ferrite composite catalyst

[0043] 0.8 g of silicon dioxide, 0.8 g of ferric oxide and 4.66 g of bismuth oxide were put into a mortar and ground with anhydrous ethanol for 0.5 hours to obtain a uniform mixed powder. The powder was placed in a nickel crucible and calcined in a muffle furnace at 600 ° C for 1 hour. After natural cooling, the bismuth silicate and bismuth ferrite composite catalyst BSFO (pure) was obtained by grinding with a mortar. The XRD pattern is shown in FIG. Figure 4 , it can be seen from the figure that it also contains Bi 25 FeO 40 and Bi 12 SiO 20 characteristic peaks.

[0044] Comparative Example 4: Preparation of amorphous manganese dioxide catalyst

[0045] 0.845 g of manganese sulfate monohydrate was dissolved in 50 mL of deionized water, recorded as solution A, 0.527 g of potassium permanganate was dissolved in 50 ml of deionized water, recorded as solution B, solution A was added dropwise to solution B to prepare a uniform mixed solution; the mixed solution was placed in a constant temperature water bath, kept warm at 50°C for 12 hours, and after natural cooling, filtered. The solid was rinsed with water 5 times, dried at 60°C for 12 hours, and ground with a mortar to obtain an amorphous manganese dioxide catalyst. The SEM image of the amorphous manganese dioxide catalyst is shown in FIG. Figure 5 From the figure, we can see that the amorphous manganese dioxide catalyst is hydrangea-shaped, and its XRD pattern is shown in Figure 1 , showing very weak diffraction peaks, indicating the amorphous structure of MnO2.

[0046] Example 6: Application of the catalysts in Examples 1-5 and Comparative Examples 1-4 in treating antibiotic wastewater

[0047] 1. Weigh 40 mg of each of the catalyst carrier BSFO and catalyst BSFM in Example 1, the bismuth silicate catalyst BSO (pure) in Comparative Example 1, the bismuth ferrite catalyst BFO (pure) in Comparative Example 2, the bismuth silicate and bismuth ferrite composite catalyst BSFO (pure) in Comparative Example 3, and the amorphous manganese dioxide catalyst in Comparative Example 4, and place them in 40 mL of a tetracycline hydrochloride solution with a concentration of 10 mg / L. After mixing, place them in an ultrasonic instrument or a constant temperature oscillator (at a speed of 120 r / min) for catalytic degradation reaction. 3 mL of tetracycline hydrochloride solution was taken at 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min, respectively. The absorbance of tetracycline hydrochloride in the solution was measured by spectrophotometer, and the degradation efficiency of tetracycline hydrochloride solution of different catalysts under different time conditions was calculated.

[0048] See the results Figure 6 、 7 As can be seen from the figure, the degradation effects of different catalysts on tetracycline hydrochloride under ultrasonic conditions for 120 minutes are better than those under oscillation conditions, and the degradation rate of tetracycline hydrochloride by the catalyst BSFM of Example 1 under ultrasonic conditions is 97.28%; both are higher than the catalyst support BSFO and the catalysts of Comparative Examples 1-4, indicating that the catalyst BSFM has efficient piezoelectric catalytic performance and can effectively catalyze the degradation of antibiotics.

[0049] The fitting results of the degradation rate constant are shown in Figure 8. It can be seen from the figure that the degradation rate of tetracycline hydrochloride by catalyst BSFM is several times that of other types of catalysts, indicating that the catalytic performance of catalyst BSFM is excellent.

[0050] 2. Degradation of tetracycline hydrochloride by the catalysts of Examples 2 to 5 under ultrasonic conditions, using the same method as above;

[0051] The degradation rate of tetracycline hydrochloride by the catalyst of Example 2 in 120 min was 87.96%, the degradation rate of tetracycline hydrochloride by the catalyst of Example 3 in 120 min was 87.96%, the degradation rate of tetracycline hydrochloride by the catalyst of Example 4 in 120 min was 92.23%, and the degradation rate of tetracycline hydrochloride by the catalyst of Example 5 in 120 min was 95.58%.

[0052] Example 7: Application of the catalysts in Examples 1-5 and Comparative Examples 1-4 in treating wastewater containing As(III)

[0053] 1. The catalyst support BSFO, catalyst BSFM, comparative example 1 bismuth silicate catalyst BSO (pure), comparative example 2 bismuth ferrite catalyst BFO (pure), comparative example 3 bismuth silicate and bismuth ferrite composite catalyst BSFO (pure), and comparative example 4 amorphous manganese dioxide catalyst in Example 1 were weighed, 40 mg each, and placed in 40 mL of 5 mg / LAs(III) solution. After mixing, the mixture was placed in an ultrasonic instrument or a constant temperature oscillator (at a speed of 120 r / min) for catalytic degradation reaction. 5 mL of As(III) solution was taken at 15 min, 30 min, 45 min, 60 min, 90 min, and 120 min, respectively. The concentration of residual As in the solution was detected by inductively coupled plasma mass spectrometry, and the degradation efficiency of As(III) solution by different catalysts under different time conditions was calculated.

[0054] See the results Figure 9 、 10 The catalyst BSFM of Example 1 showed better As(III) degradation effects than other catalysts under both ultrasonic and oscillatory conditions. The As(III) degradation rate was 76.52% after 120 min under oscillatory conditions and 95.56% after 120 min under ultrasonic conditions, indicating that the catalyst BSFM has efficient piezoelectric catalysis.

[0055] The degradation rate constant fitting results are shown in Figure 11 ,It can be seen from the figure that the rate of catalyst BSFM is dozens of times that of other catalysts, indicating that the catalytic performance of catalyst BSFM is excellent.

[0056] 2. Degradation of As(III) by the catalysts of Examples 2 to 5 under ultrasonic conditions, using the same method as above;

[0057] The degradation rate of As(III) by the catalyst of Example 2 in 120 min was 85.56%, the degradation rate of As(III) by the catalyst of Example 3 in 120 min was 88.95%, the degradation rate of As(III) by the catalyst of Example 4 in 120 min was 90.58%, and the degradation rate of As(III) by the catalyst of Example 5 in 120 min was 92.45%.

Claims

1. A method for preparing a catalyst having piezoelectric properties using copper slag, characterized in that: The dried copper slag is crushed and sieved, and then calcined at 450-550°C. The calcined copper slag is mixed with Bi2O3, and then anhydrous ethanol is added to grind and mix thoroughly. The mixture is then calcined at 550-650°C. The calcined product, manganese sulfate monohydrate, and water are mixed, and a potassium permanganate solution is added dropwise to the mixture. After mixing, the mixture is heated in a water bath at 45-55°C. The reaction product is separated into solid and liquid, and the solid is washed, dried, and ground to obtain a catalyst with piezoelectric properties.

2. The method for preparing a catalyst having piezoelectric properties using copper slag according to claim 1, characterized in that: The mass ratio of roasted copper slag to Bi2O3 is 1:0.3-2.

3. The method for preparing a catalyst having piezoelectric properties using copper slag according to claim 1, characterized in that: The mass ratio of the roasted product to manganese sulfate monohydrate is 1.7-8.5:1, and the mass ratio of the roasted product to potassium permanganate is 2.7-14:

1.

4. Use of the catalyst prepared by the method for preparing a catalyst with piezoelectric properties using copper slag according to any one of claims 1 to 3 in catalytic degradation of antibiotics and arsenic.

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