Method for preparing steel slag supported catalyst for both colorimetric detection and photocatalysis and steel slag supported catalyst

Abstract

This invention relates to a method for preparing a steel slag-supported catalyst for simultaneous colorimetric detection and photocatalysis, and to the steel slag-supported catalyst itself. The preparation method comprises the following steps: dissolving steel slag powder in water to obtain a dispersion solution; placing a magnet on the outer wall of a glass container and mechanically stirring; after settling, obtaining a mixed solution of non-magnetic steel slag powder not attracted by the magnet; centrifuging and washing to obtain non-magnetic steel slag powder; adding the obtained non-magnetic steel slag powder to water to obtain dispersion A; dissolving an organic photosensitizer with a macromolecular heterocyclic structure formed by four pyrrole subunits of α-carbon atoms interconnected by methylene bridges (=CH-) in an organic solvent to obtain solution B; mixing dispersion A and solution B uniformly and reacting them in a sealed container to obtain the steel slag-supported catalyst. The steel slag-supported catalyst prepared by this invention has advantages such as simple process, easy operation, mild reaction conditions, low cost, good stability, high sensitivity, low detection limit, and good photocatalytic performance.

Description

Technical fields:

[0001] This invention belongs to the field of composite catalyst preparation technology, and relates to a method for preparing a steel slag supported catalyst that can be used for both colorimetric detection and photocatalysis, as well as the steel slag supported catalyst. Background technology:

[0002] Water pollution, primarily caused by the indiscriminate discharge of industrial wastewater from papermaking, pharmaceuticals, printing, dyeing, and battery manufacturing, has become one of the most serious global challenges facing humanity. Antibiotics are commonly used to treat bacterial infections and sometimes as food additives to control microbial growth. However, the human body has a poor capacity to absorb antibiotics, resulting in approximately 30-90% of antibiotics entering wastewater and increasing bacterial resistance. While a series of methods for detecting and removing antibiotics have been developed, most are only suitable for a single purpose—detecting or removing pollutants in isolation. In practical applications, however, antibiotic detection and removal are complementary; detection is a necessary condition for assessing the degree of pollution, while removal is the key to environmental remediation. Therefore, efforts have been made to detect and remove antibiotics from aquatic environments.

[0003] To address the aforementioned issues, detection and degradation methods have attracted widespread attention. Among detection methods, colorimetric methods are convenient, economical, and efficient, primarily utilizing the peroxidase activity of catalysts. However, catalysts are often prone to aggregation, affecting the stability and rate of the catalytic process. Among degradation methods, photocatalytic degradation utilizes renewable solar energy as power to convert pollutants into smaller molecules, typically employing catalysts capable of degrading antibiotics under light. To improve the stability and catalytic activity of these catalysts during the catalytic process, stably loading them onto a well-suited support that does not introduce new environmental pollution has become a common approach.

[0004] Steel slag is a solid waste discharged during steel production, mainly composed of silicate and iron-containing phases. Its porous nature makes it an excellent candidate material for catalyst supports. The porosity of steel slag powder allows it to assist in dispersion, adsorption, and catalysis. Using steel slag powder as a support can effectively improve the dispersibility of the catalyst and its adsorption and capture capacity for pollutants. Furthermore, compared with pure catalysts, the cost of composite materials is significantly reduced, laying the foundation for its large-scale practical application. Non-patent literature 1 reports a study on using steel slag as a catalyst support for cerium dioxide. However, the modification techniques used to obtain the steel slag support in this technology are cumbersome and have long reaction times. Moreover, the resulting composite catalyst has poor loading performance, resulting in low sensitivity, poor performance, and poor stability.

[0005] In addition, other technologies for increasing the specific surface area of ​​steel slag powder to make modified steel slag powder a carrier have been reported in the prior art. However, it is unknown whether these modified steel slag powders are well compatible with catalysts.

[0006] It is evident that there is room for development in the use of steel slag powder as a catalyst support. There is a demand in existing technologies for novel composite catalysts using steel slag powder as a support that can be obtained more easily, with good loading capacity, good catalytic effect, strong stability, and low cost.

[0007] Existing literature

[0008] Non-patent Document 1: Kang L, Zhang YJ, Yang MY, et al. A novel V-doped CeO2 loaded alkali-activated steel slag-based nanocomposite for photocatalytic degradation of malachite green[J]. Integrated Ferroelectrics, 2016, 170(1):1-9. Summary of the Invention:

[0009] Based on the above problems, the technical objective of this invention is to provide a new method for preparing a steel slag supported catalyst, which, when used as a catalyst for colorimetric detection and photocatalysis, exhibits low detection limit, high photocatalytic activity, strong stability, and high sensitivity.

[0010] In order to achieve the above-mentioned technical objectives of the present invention, the inventors have proposed the following technical solution:

[0011] This invention provides a method for preparing a steel slag-supported catalyst that can be used for both colorimetric detection and photocatalysis, comprising the following steps:

[0012] (1) Dissolve steel slag powder in container A containing water to obtain a dispersion solution of steel slag powder; place a magnet on the outer wall of container A and stir mechanically to obtain a mixed solution of non-magnetic steel slag powder that is not attracted by the magnet.

[0013] (2) The mixed solution of steel slag powder is washed by centrifugation to obtain non-magnetic steel slag powder;

[0014] (3) Add the obtained non-magnetic steel slag powder to water to obtain dispersion A;

[0015] (4) Dissolve the organic catalyst with a macromolecular heterocyclic structure formed by the interconnection of α-carbon atoms with four pyrrole subunits through a methine bridge (=CH-) in an organic solvent to obtain solution B;

[0016] (5) After mixing the dispersion A and solution B evenly, place them in a sealed container B to react and obtain the steel slag supported catalyst.

[0017] Organic catalysts with macrocyclic structures consisting of four pyrrole subunits linked by methylene bridges (=CH-) form effective macrocyclic photosensitizers. Their broad absorption response covers almost the entire visible light spectrum. Porphyrins and their derivatives possess unique photophysical / redox properties due to their highly conjugated π-electron macrocyclic structure. Furthermore, porphyrin-based compounds can generate singlet oxygen under light irradiation, which has driven their application in photocatalysis. Despite these advantages, pure porphyrin particles themselves suffer from drawbacks such as easy aggregation, deactivation, low reusability, and rapid recombination of photocarriers, preventing their use as photocatalysts. Furthermore, when steel slag powder comes into contact with water, a hydroxylation reaction occurs on its surface. The hydrogen bonds between the hydroxyl and carboxyl groups of the porphyrin enhance the interaction between the modified steel slag powder and the porphyrin, resulting in high compatibility between the porphyrin and the non-magnetic steel slag powder carrier obtained in steps (1) and (2), and strong dispersibility of the non-magnetic steel slag powder obtained in steps (1) and (2). Therefore, the steel slag-based composite catalyst with high catalytic activity, strong stability, low detection limit, and high sensitivity desired by this invention can be obtained.

[0018] The composition of steel slag powder varies depending on its source. However, the method of wet magnetic separation followed by photosensitizer modification of the present invention demonstrates universality for various types of steel slag. Furthermore, there are no particular limitations on the particle size of the steel slag used; the raw material can be ground as needed, for example, to a median diameter D of the steel slag powder. 50 It is 10-20μm.

[0019] Furthermore, in step (1), the concentration of the steel slag powder is 10-30 g / L, more preferably 15-25 g / L; there are no particular restrictions on the container A used, as long as the relevant reaction can proceed smoothly; the mechanical stirring speed is 200-500 rpm, more preferably 200-300 rpm; the stirring time is 1-3 h, more preferably 1.5-2.5 h; the settling time is 1-2 h, more preferably 1-1.5 h.

[0020] Furthermore, in step (2), the centrifugation speed is 5000-6000 rpm, more preferably 5000-5500 rpm; the number of washing cycles is 2-4 times, more preferably 2-3 times.

[0021] Furthermore, step (2) also includes drying the non-magnetic steel slag powder, and step (5) also includes washing and drying the steel slag-supported catalyst. Of course, before washing and drying, these two steps also include separating the products, for example, using common methods such as filtration or centrifugation. There are no restrictions on the specific methods of washing and drying; any methods commonly used in the art can be employed. For example, the drying temperatures in steps (2) and (5) are each independently 65-85°C.

[0022] Furthermore, in step (2), the non-magnetic steel slag powder exhibits a layered mesoporous structure. To better facilitate the loading of organic photosensitizers with macromolecular heterocyclic structures formed by the interconnection of four pyrrole subunits of α-carbon atoms via methylene bridges (=CH-), the specific surface area (BET) of the non-magnetic steel slag powder is 2-50 m². 2 / g, for example 5-10m 2 / g; the pore size of the non-magnetic steel slag powder is concentrated in 10-40nm, for example 10-20nm; in addition, more effectively, the structure of the non-magnetic steel slag powder is a lamellar mesoporous structure.

[0023] Furthermore, in step (3), for the purpose of better loading of organic photosensitizer, the concentration of the non-magnetic steel slag powder in dispersion A is 10g / L-40g / L, more preferably 10g / L-20g / L.

[0024] Furthermore, in step (4), for the purpose of better exerting excellent catalytic effects after being loaded, the organic photosensitizer with a macromolecular heterocyclic structure formed by interconnecting α-carbon atoms of four pyrrole subunits through a methine bridge (=CH-) is at least one selected from porphyrin, tetracarboxyphenylporphyrin or porphyrin.

[0025] In addition, for the purpose of further improving the loading of photosensitizer and reducing costs, the concentration of the organic photosensitizer with a macromolecular heterocyclic structure formed by interconnecting four pyrrole subunits α-carbon atoms through a methylene bridge (=CH-) in solution B is 0.2 mg / mL-1 mg / mL, more preferably 0.2 mg / mL-0.5 mg / mL.

[0026] Furthermore, there are no particular restrictions on the type of organic solvent, as long as it can dissolve the organic photosensitizer with a macrocyclic structure formed by four pyrrole subunits of α-carbon atoms linked by a methylene bridge (=CH-). For example, amide solvents, ketone solvents, tetrahydrofuran solvents, etc., can be used.

[0027] Furthermore, in step (5), the sealed container B is a hydrothermal reactor or a benchtop high-pressure reactor.

[0028] Furthermore, in step (5), for the purpose of further and better loading of organic photosensitizer, the volume ratio of solution B to dispersion A is 1 / 10-4 / 10, more preferably 1 / 10-2 / 10.

[0029] Furthermore, in step (5), for the purpose of further improving the catalytic effect and reducing costs, the mass ratio of the non-magnetic steel slag powder in dispersion A to the organic catalyst in solution B, which has a macromolecular heterocyclic structure formed by the interconnection of α-carbon atoms with four pyrrole subunits through a methylene bridge (=CH-), is 0.05-0.2g, more preferably 0.1-0.2g, relative to 100g of non-magnetic steel slag powder.

[0030] The present invention also provides a steel slag supported catalyst that can be used for both colorimetric detection and photocatalysis, which is prepared by the above-described method.

[0031] The beneficial effects of this invention are:

[0032] By using the non-magnetic steel slag powder obtained by wet magnetic separation of the present invention as a carrier for an organic photosensitizer with a macromolecular heterocyclic structure formed by interconnecting α-carbon atoms of four pyrrole subunits through a methylene bridge (=CH-), the disadvantage of easy aggregation of organic photosensitizers can be overcome, thereby increasing its chemically active sites.

[0033] Furthermore, compared to using unmodified steel slag-supported organic photosensitizers, the steel slag-supported catalyst of this invention, prepared by this method, produces non-magnetic steel slag powder with minimal removal of the iron-containing phase, promoting the hydration reaction and resulting in more hydration products. This increases the specific surface area of ​​the non-magnetic steel slag powder carrier. Additionally, the hydroxylation reaction of the steel slag powder upon immersion in water enhances its interaction with the carboxyl groups on the photosensitizer, resulting in stronger compatibility. This reduces the aggregation of organic photosensitizers with large heterocyclic structures formed by the interconnection of four pyrrole subunits through methylene bridges (=CH-), increases the number of active sites, and improves catalytic activity. Therefore, using the steel slag-supported catalyst as a catalyst for colorimetric detection and photocatalytic degradation of solutions such as antibiotics offers advantages such as simplicity, stability, low detection limits, and high sensitivity.

[0034] In addition, using steel slag as a raw material is low-cost and low-energy-consumption, and can achieve high-value utilization of steel slag, thereby achieving the goal of treating waste with waste and protecting the ecological environment.

[0035] Furthermore, the preparation method of the present invention has the advantages of simple process, easy operation, low reaction temperature and mild conditions. Attached image description:

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0037] Figure 1 The X-ray diffraction patterns are those of the non-magnetic steel slag powder R prepared in Example 1 and the steel slag supported catalyst C1 prepared in Comparative Example 1.

[0038] Figure 2 This is a scanning electron microscope image of the steel slag supported catalyst C1 prepared in Comparative Example 1.

[0039] Figure 3 The following are spectra of absorbance changes at 652 nm caused by the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to blue in different systems: Sodium acetate buffer solution + TMB; Sodium acetate buffer solution + H2O2 + TMB; Sodium acetate buffer solution + non-magnetic steel slag powder R from Reference Example 1 + H2O2 + TMB; Sodium acetate buffer solution + steel slag supported catalyst C1 synthesized in Comparative Example 1 + H2O2 + TMB; Sodium acetate buffer solution + steel slag supported catalyst E1 synthesized in Example 1 + H2O2 + TMB; Sodium acetate buffer solution + steel slag supported catalyst E2 synthesized in Example 2 + H2O2 + TMB; Sodium acetate buffer solution + steel slag supported catalyst C1 synthesized in Comparative Example 1 + H2O2 + tetracycline + TMB;

[0040] Figure 4 The working curves for the detection of tetracycline by C1 in the steel slag supported catalyst synthesized in Comparative Example 1 are shown.

[0041] Figure 5 The following are bar charts showing the degradation rates obtained from the photocatalytic degradation performance tests of each sample: tetracycline alone, non-magnetic steel slag powder R in Reference Example 1, steel slag supported catalyst C1 prepared in Comparative Example 1, steel slag supported catalyst C2 formed by unmodified steel slag prepared in Comparative Example 2, and steel slag supported catalyst C3 formed by loading other organic matter (3,4,9,10-perylenetetracarboxylic dianhydride) onto non-magnetic steel slag of the present invention prepared in Comparative Example 3.

[0042] Figure 6 This is a summary drawing of the present invention. Detailed implementation method:

[0043] Reference example 1

[0044] Dissolve 10g of ball-milled steel slag powder in 500mL of water. Place a magnet on the outside of the beaker and mechanically stir at 300rpm for 2h. After stopping the stirring, let the non-magnetic steel slag powder stand for 1h. Collect the non-magnetic steel slag powder that has settled at the bottom of the flask, centrifuge at 5500rpm, wash with water 3 times, and then dry in an oven at 70℃ for 12h to obtain non-magnetic steel slag powder R.

[0045] Comparative Example 1

[0046] 1000 mg of non-magnetic steel slag powder R was weighed and added to 50 mL of water to obtain dispersion A; 1 mg of tetracarboxyphenylporphyrin was dissolved in 5 mL of N,N-dimethylformamide and mixed evenly to obtain solution B; dispersion A and solution B were mixed evenly and then placed in a hydrothermal reactor and reacted at 100 °C for 2 h; the resulting suspension was centrifuged at 8000 rpm, washed three times with deionized water, and dried at 70 °C for 8 h to obtain steel slag supported catalyst C1.

[0047] Comparative Example 2

[0048] 1000 mg of unmodified steel slag powder was weighed and added to 50 mL of water to obtain dispersion A; 1 mg of tetracarboxyphenylporphyrin was dissolved in 5 mL of N,N-dimethylformamide and mixed evenly to obtain solution B; dispersion A and solution B were mixed evenly and then placed in a hydrothermal reactor and reacted at 100 °C for 2 h; the resulting suspension was centrifuged at 8000 rpm, washed three times with deionized water, and dried at 70 °C for 8 h to obtain steel slag supported catalyst C2.

[0049] Comparative Example 3

[0050] 10g of ball-milled steel slag powder was dissolved in 500mL of water. A magnet was placed on the outside of the beaker, and the mixture was mechanically stirred at 300rpm for 2h. After stirring was stopped, the non-magnetic steel slag powder was allowed to stand for 1h. The non-magnetic steel slag powder that settled at the bottom of the flask was collected, centrifuged at 5500rpm, and washed with water 3 times. Then it was dried in an oven at 70℃ for 12h to obtain non-magnetic steel slag powder R.

[0051] 1000 mg of non-magnetic steel slag powder R was weighed and added to 50 mL of water to obtain dispersion A; 1 mg of 3,4,9,10-perylenetetracarboxylic dianhydride was dissolved in 5 mL of N,N-dimethylformamide and mixed evenly to obtain solution B; dispersion A and solution B were mixed evenly and then placed in a hydrothermal reactor and reacted at 100 °C for 2 h; the resulting suspension was centrifuged at 8000 rpm, washed three times with deionized water, and dried at 70 °C for 8 h to obtain steel slag supported catalyst C3.

[0052] It should be noted that the catalytic degradation abilities of tetracarboxyphenylporphyrin and 3,4,9,10-perylenetetracarboxylic dianhydride are similar and can therefore be used for comparison with the embodiments of the present invention.

[0053] Example 1

[0054] 10g of ball-milled steel slag powder was dissolved in 500mL of water. A magnet was placed on the outside of the beaker, and the mixture was mechanically stirred at 300rpm for 2h. After stirring was stopped, the non-magnetic steel slag powder was allowed to stand for 1h. The non-magnetic steel slag powder that settled at the bottom of the flask was collected, centrifuged at 5500rpm, and washed with water 3 times. Then it was dried in an oven at 70℃ for 12h to obtain non-magnetic steel slag powder R.

[0055] 1000 mg of non-magnetic steel slag powder R was weighed and added to 50 mL of water to obtain dispersion A; 0.5 mg of tetracarboxyphenylporphyrin was dissolved in 5 mL of N,N-dimethylformamide and mixed evenly to obtain solution B; dispersion A and solution B were mixed evenly and then placed in a hydrothermal reactor and reacted at 100 °C for 2 h; the resulting suspension was centrifuged at 8000 rpm, washed three times with deionized water, and dried at 70 °C for 8 h to obtain steel slag supported catalyst E1.

[0056] Example 2

[0057] 10g of ball-milled steel slag powder was dissolved in 500mL of water. A magnet was placed on the outside of the beaker, and the mixture was mechanically stirred at 300rpm for 2h. After stirring was stopped, the non-magnetic steel slag powder was allowed to stand for 1h. The non-magnetic steel slag powder that settled at the bottom of the flask was collected, centrifuged at 5500rpm, and washed with water 3 times. Then it was dried in an oven at 70℃ for 12h to obtain non-magnetic steel slag powder R.

[0058] 1000 mg of non-magnetic steel slag powder R was weighed and added to 50 mL of water to obtain dispersion A; 2 mg of tetracarboxyphenylporphyrin was dissolved in 5 mL of N,N-dimethylformamide and mixed evenly to obtain solution B; dispersion A and solution B were mixed evenly and then placed in a hydrothermal reactor and reacted at 100 °C for 2 h; the resulting suspension was centrifuged at 8000 rpm, washed three times with deionized water, and dried at 70 °C for 8 h to obtain steel slag supported catalyst E2.

[0059] The steel slag used in the above-mentioned reference examples, comparative examples, and embodiments all came from Baosteel Zhanjiang Iron and Steel Plant, and all other reagents were of analytical grade.

[0060] The obtained product was tested, and the results were as follows: Figure 1 , Figure 2 As shown. Figure 1 The X-ray diffraction patterns are those of the non-magnetic steel slag powder R prepared in Example 1 and the steel slag-supported catalyst C1 prepared in Comparative Example 1; from Figure 2 The scanning electron microscope images show that the steel slag supported catalyst C1 exhibits a layered mesoporous structure.

[0061] Evaluation of colorimetric detection performance:

[0062] Group 1:

[0063] The catalytic activity of different materials was investigated. The catalytic activity of different materials was evaluated by the change in absorbance at 652 nm caused by the blue color change of 3,3',5,5'-tetramethylbenzidine (TMB) activated by H2O2. 5 mg of the non-magnetic steel slag powder R prepared in Reference Example 1, the steel slag supported catalyst C1 prepared in Comparative Example 1, the steel slag supported catalyst E1 prepared in Example 1, and the steel slag supported catalyst E2 synthesized in Example 2 were weighed and diluted to 10 mL in volumetric flasks respectively. 245 μL of 30 wt.% H2O2 was measured and diluted to 10 mL in a volumetric flask to prepare a 24 μM H2O2 solution. 3.1 mg of TMB was weighed and diluted to 10 mL in a volumetric flask to prepare a 1 mM TMB solution. 3.6 mg of TC was weighed and diluted to 100 mL in a volumetric flask to prepare a 36 mg / L TC solution. Add 200 μL each of sodium acetate buffer solution, catalyst solution, H₂O₂ solution, TC solution, and TMB solution sequentially to a cuvette, for a total volume of 2 mL. Incubate for 3 minutes, then observe the changes in absorbance at 652 nm under different reaction systems. The experimental results are as follows: Figure 3 As shown.

[0064] Experimental results demonstrated the catalytic activity of this series of materials for H2O2 activation. Compared to the porphyrin-modified non-magnetic steel slag powder system, the absorbance at 652 nm was significantly reduced when only non-magnetic steel slag powder was used, indicating that the addition of porphyrin improved the catalytic effect of the non-magnetic steel slag powder. When the porphyrin content in the steel slag-supported catalyst increased, the absorbance at 652 nm showed a phenomenon of first increasing and then decreasing, indicating that the catalytic activity of the steel slag-supported catalyst was highest when the porphyrin addition amount was 1 mg. The catalytic effect of the steel slag-supported catalyst was significant in the range of 0.05-0.2 g of photosensitizer relative to 100 g of inorganic modified steel slag powder, especially in the range of 0.1-0.2 g. When different concentrations of TC were added, the absorbance at 625 nm increased, indicating that tetracycline and the catalyst had a synergistic promoting effect on the catalytic activity of H2O2 activation.

[0065] Group 2:

[0066] The detection of tetracycline was assessed by evaluating the different promoting effects of different concentrations of tetracycline on the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by the catalyst-activated H₂O₂. 5 mg of the steel slag-supported catalyst C₁ prepared in Comparative Example 1 was weighed and diluted to a 10 mL volumetric flask. 245 μL of 30 wt.% H₂O₂ was measured and diluted to a 10 mL volumetric flask to prepare a 24 μM H₂O₂ solution. 3.1 mg of TMB was weighed and diluted to a 10 mL volumetric flask to prepare a 1 mM TMB solution. 9.6 mg of tetracycline was weighed and diluted to a 100 mL volumetric flask to prepare a 96 mg / L TC solution. These solutions were then diluted to different concentrations of tetracycline. In one group, buffer solution, catalyst solution (200 μL), H₂O₂ solution (200 μL), and TMB solution (200 μL) were added sequentially to a cuvette, with a total volume of 2 mL. After incubation for 3 minutes, the absorbance of the system at 652 nm was measured as A1. In another group, buffer solution, catalyst solution (200 μL), H₂O₂ solution (200 μL), TC solution of different concentrations (200 μL), and TMB solution (200 μL) were added sequentially to a cuvette, with a total volume of 2 mL. After incubation for 3 minutes, the absorbance of the system at 652 nm was measured as A2. At this TC concentration, the change in absorbance was ΔA = A2 - A1. The experimental results are as follows. Figure 4 As shown.

[0067] Experimental results show that the catalyst can achieve the detection of tetracycline. As the tetracycline concentration increases, ΔA gradually increases, reaching equilibrium at a tetracycline concentration of 90 μM. Within the range of 2.5–50 μM, there is a linear relationship between the tetracycline concentration x and the change in absorbance y, with the linear equation being y = 0.0114x - 0.0208, R0. 2 =0.9989, detection limit: LOD=3s / k=2.45μM, where s is the standard deviation of the test results when the number of independent tests is 10, s=0.00931, and k is the slope of the fitted linear equation, k=0.0114.

[0068] Evaluation of photocatalytic degradation performance:

[0069] 1. Weigh 3.6 mg of tetracycline (TC), dilute to 100 mL in a volumetric flask, and prepare a solution C with a mass concentration of 36 mg / L. Measure the initial absorbance value of solution C.

[0070] 2. Weigh 5 mg each of the non-magnetic steel slag powder R prepared in Reference Example 1, the steel slag supported catalyst C1 prepared in Comparative Example 1, the steel slag supported catalyst C2 prepared in Comparative Example 2, and the steel slag supported catalyst C3 prepared in Comparative Example 3, and dissolve them in 40 mL of solution C respectively. Disperse them evenly under ultrasonic conditions to obtain solutions D, E, F and G.

[0071] 3. Irradiate solutions C, D, E, F, and G under visible light. After 60 minutes, take out 3 mL of the solution, centrifuge, and measure the absorbance of the supernatant.

[0072] 4. Calculate its photocatalytic degradation efficiency, degradation rate as follows: Figure 5 .

[0073] Experimental results show that the degradation rate of tetracycline solution under visible light irradiation is 0.03%. The photocatalytic degradation rate of steel slag supported catalyst C1 reached 79% after 60 minutes, while the photocatalytic degradation rates of non-magnetic steel slag powder R, steel slag supported catalyst C2, and steel slag supported catalyst C3 were 57%, 47%, and 26%, respectively. Therefore, the steel slag supported catalyst prepared in this invention exhibits good photocatalytic degradation activity in the visible light region and can effectively catalyze the degradation of antibiotics (tetracycline) in water and other environments.

[0074] In summary, the steel slag-supported catalyst C1 can be used simultaneously for the colorimetric detection and photocatalytic degradation of tetracycline, such as... Figure 6 The steel slag supported catalyst prepared by this invention has great application value in water treatment.

Claims

1. A method for the preparation of steel slag supported catalyst for simultaneous colorimetric detection and photocatalysis, characterized by, The method comprises the following steps: (1) dissolving steel slag powder in a container A containing water to obtain a dispersed solution of the steel slag powder; placing a magnet outside the wall of the container A, and obtaining a mixed solution of non-magnetic steel slag powder not attracted by the magnet through mechanical stirring and standing; (2) preparing non-magnetic steel slag powder by centrifugal washing of the mixed solution of the non-magnetic steel slag powder; (3) adding the obtained non-magnetic steel slag powder into water to obtain a dispersion A; (4) dissolving an organic catalyst having a porphyrin macromolecular heterocyclic structure formed by interlinking of alpha-carbon atoms of four pyrrole-like radicals through a methine bridge in an organic solvent to obtain a solution B, wherein the methine bridge structure is =CH-; (5) mixing the dispersion A and the solution B uniformly, and then placing them in a sealed container B to react, thereby preparing a steel slag loaded catalyst.

2. The preparation method of the steel slag supported catalyst according to claim 1, characterized in that, In step (1), the concentration of the steel slag powder is 10-30 g / L; the container A is a commonly used glass instrument in experiments; the stirring speed of the mechanical stirring is 200-500 rpm, the stirring time is 1-3 h, and the standing time is 1-2 h.

3. The method for preparing a steel slag supported catalyst according to claim 1, characterized by, In step (2), the centrifugal speed is 5000-6000 rpm, and the washing times are 2-4 times.

4. The method for preparing a steel slag supported catalyst according to claim 1, characterized by, Step (2) further comprises drying of the non-magnetic steel slag powder, and step (5) further comprises washing and / or drying of the steel slag loaded catalyst, and the drying temperature in steps (2) and (5) is independently 65-85 ℃.

5. The method for preparing the steel slag supported catalyst according to claim 1, characterized in that, In step (2), the specific surface area BET of the non-magnetic steel slag powder is 10-50 m² / g, the pore size is concentrated in 10-40 nm, and the structure is mesoporous structure.

6. The method of claim 1, wherein the steel slag supported catalyst is prepared by the steps of: (a) mixing a steel slag with a solution of a transition metal salt; (b) drying the mixture; (c) calcining the dried mixture; and (d) reducing the calcined mixture. In step (3), the concentration of the non-magnetic steel slag powder in the dispersion A is 10 g / L-40 g / L; in step (4), the organic catalyst having a porphyrin macromolecular heterocyclic structure formed by interlinking of alpha-carbon atoms of four pyrrole-like radicals through a methine bridge is at least one selected from porphine and tetracarboxyphenyl porphyrin; and the concentration of the organic catalyst having a porphyrin macromolecular heterocyclic structure formed by interlinking of alpha-carbon atoms of four pyrrole-like radicals through a methine bridge in the solution B is 0.2 mg / mL-1 mg / mL.

7. The method of claim 1, wherein the steel slag supported catalyst is prepared by the steps of: (a) mixing a steel slag with a solution of a transition metal salt; (b) drying the mixture; (c) calcining the dried mixture; and (d) reducing the calcined mixture. In step (5), the sealed container B is a hydrothermal reaction kettle or a benchtop high-pressure reaction kettle.

8. The method of claim 1, wherein the steel slag supported catalyst is prepared by the steps of: a) mixing the steel slag and the metal oxide; b) calcining the mixture; and c) reducing the calcined mixture. In step (5), the volume ratio of the solution B to the dispersion A is 1 / 10-4 / 10.

9. The method for preparing the steel slag supported catalyst according to claim 1, characterized in that, In step (5), the mass ratio of the non-magnetic steel slag powder in the dispersion A to the organic catalyst having a porphyrin macromolecular heterocyclic structure formed by interlinking of alpha-carbon atoms of four pyrrole-like radicals through a methine bridge in the solution B is 100 g of the non-magnetic steel slag powder to 0.05-0.2 g of the organic catalyst.

10. A steel slag supported catalyst for simultaneous colorimetric detection and photocatalysis, characterized in that, The steel slag loaded catalyst is prepared by the method of any one of claims 1-9.

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