Titanium-based mof porous carbon derived from printing and dyeing alkali reduction white mud and preparation method and application thereof

Abstract

The present application provides printing and dyeing alkali reduction white mud derived titanium-based MOF porous carbon and its preparation method and application, the inherent BDC in the white mud is extracted for resourceization, and the titanium-based MOF structure porous derived carbon is prepared for the electrocatalytic reduction degradation of florfenicol. The MOF material has the characteristics of high porosity, adjustable pore size structure size, high specific surface area, which enhances the enrichment of pollutants, is also beneficial to the activation of active sites and catalytic conversion of substances. In summary, the catalytic performance of the electrode material is improved, the efficient reduction degradation of florfenicol is realized, and the electrode material used in the present application is a non-noble metal material, which is low in price and simple in preparation, and meets the green economy and sustainable development concept.

Description

Technical Field

[0001] This invention belongs to the technical field of treating florfenicol antibiotic pollutants, specifically relating to a method for preparing porous derived carbon with a titanium-based organometallic framework (MOF) structure prepared from terephthalic acid (BDC) extracted from dyeing alkali reduction white mud, and its application in the cathodic electrocatalytic reduction degradation of florfenicol. Background Technology

[0002] Florfenicol (FLO) is a commonly used broad-spectrum veterinary antibiotic with strong antibacterial properties but poor biodegradability. Its chemical structure contains halogen elements, making it biotoxic. Therefore, florfenicol exhibits high tolerance to conventional water treatment technologies (especially biological treatment). For example, Jiang et al. reported that florfenicol is difficult to remove by conventional biochemical methods in wastewater treatment plants. Furthermore, recent studies have shown that residual antibiotics (such as florfenicol) in water bodies can induce the development of antibiotic resistance genes and antibiotic-resistant pathogens in the environment, further impacting human health.

[0003] Extensive research by domestic and international researchers has shown that methods used for removing organic pollutants from water can be applied to the removal of antibiotic pollutants. These methods primarily include biological, physical, and chemical treatments. Biological treatment methods mainly consist of aerobic and anaerobic processes. These two technologies offer advantages such as economy, efficiency, and energy saving. However, aerobic methods require dilution when treating antibiotic wastewater with high COD, increasing treatment costs. Anaerobic methods do not completely degrade organic matter, thus limiting the development of this technology. Physical treatment methods mainly include adsorption, membrane technology, and coagulation. While these methods can reduce antibiotic concentration, adsorption only enriches or concentrates pollutants from the aqueous phase to the adsorbent surface, without reducing their toxicity. Therefore, there is still a risk of pollutants being released back into the environment, and the adsorbent requires subsequent treatment after adsorption. Chemical treatment methods include chemical oxidation and photocatalytic oxidation. These methods mainly generate highly oxidizing ·OH, thereby oxidizing all organic pollutants in the water into inorganic substances, but sometimes chemical reagents need to be added. In comparison, electrochemical reduction is a greener and more efficient method that does not require the addition of additional chemical reagents. It can effectively convert and remove various organic pollutants (such as halogenated organic pollutants and nitro-containing organic pollutants) by using electrons provided by the cathode.

[0004] To date, electrochemical catalytic materials are mainly noble metal catalysts (such as Pd and Ag-based materials), which exhibit good catalytic reduction activity at low overpotentials. However, their commercial application is limited due to their high cost. Therefore, the attention given to non-noble metal catalysts has been continuously increasing. Currently, non-noble metal catalysts can be divided into transition metal oxides, organic framework materials, transition metal sulfides, transition metal phosphides, and transition metal hydroxides. Transition metal oxide materials have the characteristics of good chemical stability, low cost, and good structural controllability. Titanium dioxide (TiO2) is a typical transition metal oxide. TiO2 has good chemical stability and photoresponse characteristics and is often used in photocatalysis. However, by using defect engineering and surface morphology engineering, the conductivity of TiO2 can be improved. For example, Zhang Aiyong et al. prepared TiO2 with different oxygen vacancies using different calcination temperatures to improve the removal efficiency of p-nitrobenzene.

[0005] Metal-organic framework (MOF) materials possess characteristics such as large specific surface area, high porosity, well-structured framework, controllable pore structure, and high crystallinity, making them promising candidates for catalysis. Furthermore, MOF porous carbon derived through pyrolysis using MOFs as sacrificial templates offers unique advantages: (1) it requires no additional template, simplifying the synthesis method; (2) it inherits the high specific surface area and porous structure of MOFs, facilitating mass transfer and exposing active sites; and (3) the morphology and structure of the derived material can be controlled by designing MOF precursors. In conclusion, derived MOF porous carbon holds significant importance for catalytic applications. Therefore, porous carbon derived from Ti-based MOFs theoretically possesses a large specific surface area and a high-density porous structure, which can improve the mass transfer efficiency of pollutants and expose more active sites, thus exhibiting excellent catalytic performance.

[0006] The main process units in the dyeing and printing industry include desizing, scouring, bleaching, dyeing, printing, alkali reduction, and wool washing. Alkali reduction involves treating polyester fabric with sodium hydroxide solution (NaOH) at room temperature or a certain temperature. In this process unit, concentrated NaOH solution is used to treat the polyester fabric. Since the main component of polyester fabric is polyethylene terephthalate (PET), it is partially depolymerized and hydrolyzed into sodium terephthalate (BDC) and ethylene glycol, which dissolve in the alkali reduction wastewater. To separate BDC from the wastewater, acid precipitation is performed. During this process, concentrated sulfuric acid (H₂SO₄) is used to adjust the pH (to 3-5), converting sodium terephthalate into BDC, which has extremely low solubility, and causing it to precipitate. Simultaneously, coagulants such as polyferric sulfate / polyaluminum chloride are used to promote the sedimentation of BDC flocs. Finally, the precipitate is dewatered using a plate and frame filter press to form the alkali reduction sludge from the dyeing and printing industry.

[0007] In summary, the main component of the alkali-reduced white mud in dyeing and printing is BDC, along with small amounts of undepolymerized oligomers, ethylene glycol, and iron / aluminum inorganic salts. If BDC extracted from the alkali-reduced white mud is used as a ligand molecule, and an external Ti source is added as a metal node to construct a MIL-125(Ti) type MOF material, and titanium-based MOF porous carbon is derived through pyrolysis as a catalyst for electrochemical reduction, it can not only inherit the porous structure of Ti-based MOF materials but also construct abundant active sites, thereby enhancing the activity of electrochemical reduction of FLO. However, the development of titanium-based MOF porous carbon derived from alkali-reduced white mud in dyeing and printing is currently a blank area. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing titanium-based MOF structured porous derived carbon electrode materials by means of terephthalic acid (BDC) extracted from alkali-reduced white mud.

[0009] Another object of the present invention is to provide a titanium-based MOF porous carbon electrode material derived from dyeing alkali reduction white mud prepared by the method.

[0010] Another object of the present invention is to provide the application of titanium-based MOF porous carbon electrode material derived from dyeing alkali reduction white mud in the cathodic reduction degradation of florfenicol.

[0011] The objective of this invention is achieved through the following technical solution:

[0012] In a first aspect, the present invention provides a titanium-based MOF porous carbon (hereinafter referred to as TiO2@CW) derived from dyeing alkali reduction white mud, wherein the titanium-based MOF porous carbon derived from dyeing alkali reduction white mud is prepared according to the following method:

[0013] S1: Disperse the white mud with reduced dyeing alkali evenly in an organic solvent, shake thoroughly, and filter. The resulting filtrate is a solution containing terephthalic acid. The organic solvent is a mixture of N,N-dimethylformamide and methanol in a volume ratio of 1 to 8:1 (preferably 4:1).

[0014] The dyeing and printing alkali reduction sludge comes from the following process: after the polyester is singed, it is desized with NaOH, sodium sulfate, sodium tripolyphosphate, polyether-modified polydimethylsiloxane, and oxalic acid, and then alkali reduction is performed with NaOH solution. The resulting wastewater is adjusted to pH=3-5 for acid precipitation and then precipitated with polyferric sulfate and polyaluminum chloride. The resulting mixture is dewatered by a plate and frame filter press, and the resulting filter cake is the dyeing and printing alkali reduction sludge.

[0015] S2: Titanium tetraisopropoxide is added dropwise to the terephthalic acid-containing solution described in step S1 under (vigorous) stirring. After the addition is complete, the solution is stirred and hydrolyzed for 1-4 hours (preferably 2 hours for complete hydrolysis). Then, it is transferred to a hydrothermal reactor lined with polytetrafluoroethylene and hydrothermally reacted at 120-150°C for 10-24 hours (preferably 150°C for 15 hours). The resulting reaction solution is separated and washed to obtain titanium-based MOF. The molar ratio of terephthalic acid to titanium tetraisopropoxide in the terephthalic acid-containing solution is 3:0.5-5 (preferably 3:1). S3: The titanium-based MOF described in step S2 is calcined at 200-400°C for 1-3 hours (preferably 350°C for 1 hour) in a protective atmosphere to obtain the titanium-based MOF porous carbon derived from the dyeing alkali reduction white mud.

[0016] Furthermore, in step S1, the volume of the organic solvent is 30-100 mL / g based on the mass of the dyeing alkali reduction white mud (50 mL / g in one embodiment of the present invention).

[0017] Furthermore, in step S1, the oscillation is carried out in a multi-tube vortex mixer, and the oscillation conditions are: 60W, rotation speed of 2500rpm, and oscillation time of 6-24h (at least 6h, preferably 12h).

[0018] In an embodiment of the present invention, the concentration of terephthalic acid in the solution containing terephthalic acid in step S2 is detected by HPLC. In one embodiment of the present invention, the concentration of terephthalic acid in the solution containing terephthalic acid is 30.77%. The next experiment can proceed once the concentration reaches 20% or higher.

[0019] Further, the separation and washing in step S2 is as follows: the reaction solution is cooled to room temperature, centrifuged, and the resulting precipitate is washed by centrifugation with DMF and methanol in sequence, and then dried (dried at 60°C in a vacuum drying oven) to obtain the titanium-based MOF.

[0020] Furthermore, the protective atmosphere described in step S3 is a nitrogen atmosphere.

[0021] Secondly, the present invention provides a TiO2@CW electrode prepared from titanium-based MOF porous carbon (TiO2@CW) derived from the above-mentioned dyeing alkali reduction white mud.

[0022] Specifically, the TiO2@CW electrode is prepared using the following method:

[0023] TiO2@CW material, 5wt% The TiO2@CW material was uniformly dispersed in a mixed solvent of anhydrous ethanol and isopropanol to obtain ink; the mass of the TiO2@CW material was 5 wt% of... The volume ratio is 1 mg: 1.33–2.66 μL;

[0024] The ink is applied to both sides of the pretreated carbon paper and dried to obtain the TiO2@CW electrode; the mass of the TiO2@CW material, based on the single-sided area of ​​the pretreated carbon paper, is 0.2–1.875 mg / cm². 2 (In one embodiment of the present invention, 1.875 mg / cm³ is preferred.) 2 ).

[0025] Furthermore, those skilled in the art will know that carbon paper needs to be pretreated when preparing electrodes. The pretreated carbon paper is obtained by the following method: soaking in 0.5M H2SO4, followed by ultrasonic washing with deionized water and anhydrous ethanol to obtain the pretreated carbon paper.

[0026] Thirdly, the present invention provides the application of the above-mentioned TiO2@CW electrode as a cathode material in the electrochemical reduction and degradation of antibiotic organics.

[0027] Furthermore, the antibiotic organic compound is one or more of levofloxacin, furacilin, metronidazole, and florfenicol.

[0028] Specifically, the application is as follows: in an H-type double-chamber sealed electrolytic cell, a three-electrode system is formed with the TiO2@CW electrode as the working electrode, a platinum sheet (1cm×1cm) as the counter electrode, and an Ag / AgCl electrode as the reference electrode. An aqueous solution containing 10-100mM (preferably 40mM) Na2SO4 and 2mg / L (preferably 50mg / L) antibiotic organic matter is used as the cathode solution, and an aqueous solution containing 10-100mM (preferably 50mM) Na2SO4 is used as the anolyte. Electrochemical reduction degradation is carried out at -0.4V to -1.2V (preferably -1.2V).

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) In this invention, the BDC contained in the alkali reduction white mud of printing and dyeing is recycled and utilized, and a derived titanium-based MOF porous carbon material is designed and prepared by pyrolysis.

[0031] (2) The titanium-based MOF porous carbon electrode material derived from the dyeing alkali reduction white mud in this invention has a good degradation effect on a variety of typical antibiotic pollutants.

[0032] (3) The titanium-based MOF porous carbon electrode material derived from the dyeing alkali reduction white mud in this invention also has a good degradation effect under common anion interference conditions.

[0033] (4) The titanium-based MOF porous carbon electrode material derived from the dyeing alkali reduction white mud in this invention has a good degradation effect under a wide range of pH conditions.

[0034] (5) In this invention, when the mass ratio of BDC to Ti source material is 3:1 and the calcination temperature is 350℃, the titanium-based MOF porous carbon electrode material derived from dyeing alkali reduction white mud has the best degradation effect on florfenicol. Attached Figure Description

[0035] Figure 1 (A) Elemental composition and (B) Scanning electron microscopy (SEM) morphology, EDS spectrum and elemental composition of alkali-reduced white mud for dyeing and printing: Figure 1 In Example 1, elemental composition and morphological structure analysis were performed on the alkali-reduced white mud used in dyeing and printing. The purpose was to clarify the components of the alkali-reduced white mud.

[0036] Figure 2 N2 adsorption-desorption isotherms:

[0037] Figure 2 In Example 2, the specific surface area of ​​titanium-based MOF porous carbon derived from dyeing alkali reduction white mud and titanium-based MOF porous carbon derived from pure BDC were compared. The purpose was to compare the specific surface area of ​​the two materials.

[0038] Figure 3 Comparison of the degradation effects of different materials on florfenicol:

[0039] Figure 3 The electrode materials obtained by different methods in Example 3 were tested for their degradation effect on florfenicol under an applied voltage of -1.2V. The purpose of this study was to verify the feasibility of the method of using titanium-based MOF porous carbon derived from dyeing alkali reduction white mud.

[0040] Figure 4 Degradation effect of electrode materials prepared at different temperatures on florfenicol:

[0041] Figure 4 Degradation experiments were conducted on the electrode materials prepared at different temperatures in Example 4. It was found that the material obtained after calcination at 400°C showed the best degradation of 20 ppm florfenicol at -1.2V, followed by 350°C, and lastly 200°C.

[0042] Figure 5 The degradation performance of florfenicol by different BDC:Ti source molar ratios:

[0043] Figure 5 The purpose of this study is to investigate the effect of the amount of Ti source material on the degradation performance of florfenicol in Example 5.

[0044] Figure 6 Investigation of the stability of materials against the degradation of florfenicol:

[0045] Figure 6 This study investigates the degradation stability of the material in Example 6 against florfenicol. The aim is to demonstrate that the material exhibits good stability.

[0046] Figure 7 Degradation capacity under different pH and anion interference conditions:

[0047] Figure 7 This example illustrates the degradation effect of the electrode material in Example 7 on florfenicol within a pH range of 3.88–9.74, and under conditions of high concentrations of interfering substances. The aim is to highlight the material's superior anti-interference capability.

[0048] Figure 8 The degradation ability of electrode materials for different pollutants:

[0049] Figure 8 The purpose of this study is to demonstrate the degradation of different antibiotic contaminants (including furacilin (NFZ), florfenicol (FLO), metronidazole (MNZ), and levofloxacin (LFX)) by the electrode material in Example 8, highlighting the versatility of the material and its ability to degrade other contaminants. Detailed Implementation

[0050] The present invention will be further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Test methods in the following examples that do not specify specific experimental conditions are generally performed under conventional experimental conditions. Unless otherwise specified, the reagents and raw materials used in the present invention are all commercially available.

[0051] The alkali-reducing white mud mentioned is the product of dewatering the entire mixed liquor in the alkali-reduction process section of the dyeing plant using a plate and frame filter press. The dyeing plant's process flow is: polyester → fabric mixing tank → singeing → scouring (desizing) → (alkali reduction) → dyeing → setting → softening finishing → trimming → calendering → steaming. The main process parameters are: ① Singeing; singeing not only makes the fabric surface smooth and clean, but also improves the pilling and fuzzing phenomenon during wear. The flame temperature for singeing is usually 900-1000℃, using gasoline or natural gas. ② Scouring; the main purpose is to remove oil and impurities from the polyester. Caustic soda (NaOH), degreasing agents (sodium sulfate, sodium tripolyphosphate, polyether-modified polydimethylsiloxane), and cleaning agents (oxalic acid) are used. ③ Alkali Reduction: During alkali reduction treatment, the polyester surface is corroded by alkali, resulting in reduced weight, thinner fiber diameter, and pitted surface. This decreases fiber stiffness, eliminates the sheen of the polyester filaments, and increases the gaps at the fabric's interlacing points, making the fabric softer, more lustrous, and improving moisture absorption and wicking. Alkali reduction treatment utilizes the peeling effect of caustic soda on polyester to improve softness and reduce pilling. Caustic soda (NaOH) is used at 125℃. ④ Dyeing: Polyester is dyed to meet consumer demand. This is done using dyes (imine blue, formamide yellow, azo yellow), surfactants (polyether-modified polydimethylsiloxane), sodium sulfate, and sodium dithionite, among other chemical reagents. ⑤ Heat Setting: Heat setting improves the dimensional stability of polyester, making it less prone to deformation even under humid and hot dyeing and finishing conditions and during subsequent use. This is done at 180–190℃. ⑥ Softening Finishing; During the dyeing and finishing process, textiles undergo wet heat treatment with various chemical reagents and are subjected to mechanical tension, which not only alters their structure but also causes a stiff and rough hand feel. Softening finishing can compensate for these defects, making the fabric soft to the touch. Chemical softening finishing uses softeners to reduce the coefficient of friction between fibers to achieve a softening effect. Hydrophilic amino silicone softeners are used in this process.

[0052] In summary, the wastewater from dyeing and printing plants contains chemical reagents from multiple processes. This patent mainly focuses on dewatering the entire mixed liquor from the alkali reduction process in dyeing and printing using a plate and frame filter press. The main operations are as follows: In the process unit, concentrated NaOH solution is used to treat polyester fabric. The main component of polyester fabric is polyethylene terephthalate (PET), which is partially depolymerized and hydrolyzed into sodium terephthalate (BDC) and ethylene glycol, dissolving in the alkali reduction wastewater. To separate BDC from the wastewater, acid precipitation is performed. During this process, concentrated sulfuric acid (H2SO4) is used to adjust the pH (to pH = 3-5), converting sodium terephthalate into BDC, which has extremely low solubility, and causing it to precipitate. Simultaneously, polyferric sulfate / polyaluminum chloride coagulants are used to promote the aggregation and sedimentation of BDC flocs. It may also contain a small amount of surfactant (polyether-modified polydimethylsiloxane) impurities introduced during the boiling and refining process. Finally, the entire mixture is dewatered by a plate and frame filter press to form the dyeing and printing alkali reduction white mud.

[0053] Example 1: Elemental composition and morphological structure analysis of alkali-reduced white mud used in dyeing and printing.

[0054] In this invention, the alkali-reducing white mud involved in the examples was subjected to elemental analysis. A scanning electron microscope (SEM, Hitachi S-3000N) with a Cu Kα X-ray source and energy-dispersive spectroscopy (EDS) and a transmission electron microscope (TEM, JEM-1230JEOL) were used to analyze the elemental composition and morphological structure of the white mud. The results are as follows: Figure 1 As shown in A and B, the main elemental composition of the white mud includes C, H, Fe, and Al. The presence of Fe and Al is primarily attributed to the polyferric sulfate / polyaluminum chloride coagulant used in the alkali reduction process unit of the dyeing and printing white mud. Based on area scanning, as... Figure 1 B, only C and O elements were observed, corresponding to the BDC component.

[0055] Example 2: Comparison of specific surface area of ​​TiO2@C and TiO2@CW materials

[0056] The TiO2@C and TiO2@CW materials in this invention are obtained by the following preparation methods:

[0057] (1) Synthesis of porous derived carbon (TiO2@C) material prepared from pure BDC: 0.0312 g of BDC (jg-P816020-100 g) was weighed and added to a mixture of 40 mL DMF (by-d112004-500 mL) and 10 mL methanol, and sonicated for more than 20 minutes to ensure the dissolution of BDC. Then, 50 mL of the mixture was transferred to the lining of a 100 mL hydrothermal reactor, and 1.3 mL of tetraisopropoxide titanium (01432850-Alfa#077115-100 g) was gradually added dropwise under vigorous stirring. The molar ratio of BDC to Ti source was 3:1. After stirring for 2 hours, the hydrothermal reactor was kept at 150 °C for 15 hours. After cooling to room temperature, it was washed several times by centrifugation with DMF and methanol, then dried at 60°C in a vacuum drying oven, and finally calcined at 350°C for 1 hour in a tube furnace under N2 atmosphere, and then naturally cooled to room temperature to obtain TiO2@C powder.

[0058] (2) Synthesis of TiO2@CW material: The preparation conditions are the same as in Example 2(1), the only difference being that the BDC used is extracted from the white mud of the dyeing and printing alkali reduction. The specific extraction operation is as follows: 2.0288g of white mud solid was added to 80mL of N,N-dimethylformamide (DMF, by-d112004-500mL) and 20mL of methanol (MeOH), and shaken for 12h using a multi-tube vortex mixer (QL-866, 60W, 2500rpm), and then filtered using a vacuum filter. The obtained filtrate is a solution containing BDC (the concentration of BDC in the filtrate was 624.17mg / L as determined by HPLC). Then, 50mL of the filtrate was transferred to the lining of a 100mL hydrothermal reactor, and the subsequent preparation operation was the same as in Example 2(1), to obtain TiO2@CW powder.

[0059] The N2 adsorption-desorption isotherms of these two materials were fitted, and the results are as follows: Figure 2 As shown, TiO2@CW material has a specific surface area 25 times that of TiO2@C material. TiO2@CW material has a large specific surface area, therefore it has more active sites.

[0060] Example 3: Effect of materials prepared under different conditions and methods on the degradation of florfenicol

[0061] In this invention, the TiO2 and TiO2 prepared in the examples are used. 2-xA three-electrode system was constructed using porous derived carbon (TiO2@C), TiO2@CW, and Pd (3 wt.%) / C prepared from pure BDC as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl reference electrode as the reference electrode. Na2SO4 (water as the solvent) was used as the electrolyte, and the system was finally assembled into a florfenicol H-type dual-chamber sealed electrolytic cell degradation device. The working electrode was prepared by the following method:

[0062] (1) Synthesis of TiO2 material: 25 mL of tetrabutyl titanate (shmu-T818870-500 ml) was added to a 100 mL polytetrafluoroethylene-lined hydrothermal reactor and magnetically stirred for 30 minutes. Under vigorous stirring, 3 mL of hydrofluoric acid (40 wt%, solvent: water, H811357-500 ml) was added dropwise, and stirring was maintained for 2 hours. The hydrothermal reactor was then kept at 180 °C for 24 hours. After cooling to room temperature, the mixture was centrifuged, and the resulting white gel powder was washed several times with deionized water and anhydrous ethanol. It was then dried overnight at 80 °C. Finally, it was calcined in a muffle furnace at 500 °C for 2 hours and naturally cooled to room temperature to obtain TiO2 powder.

[0063] (2) Synthesis of TiO 2-x Materials: The TiO2 powder prepared in step (1) was physically ground and mixed with sodium borohydride (GY-S108355-100g) at a mass ratio of 1:7 for 20 min, and then calcined at 400℃ for 2 hours under a nitrogen atmosphere. Finally, the cooled sample was washed with deionized water and anhydrous ethanol to remove residual sodium borohydride and its decomposition products, and dried at 60℃ to obtain TiO2. 2-x powder.

[0064] (3) Take 7.5 mg and 10 μL of the TiO2 material prepared in Example 3 (1). Ink was formed by ultrasonically treating a mixture of 5wt% (BY-N169478-5ml), 4.5mL anhydrous ethanol, and 1.5mL isopropanol for at least 10 minutes. Under an infrared baking lamp, the ink was applied with a brush to pre-treated carbon paper (2cm x 2cm sheets of carbon paper soaked in 0.5M H2SO4 and ultrasonically washed with deionized water and anhydrous ethanol). This amount was applied to one side only, requiring application to both sides. After complete application, the paper was placed in a 60℃ vacuum drying oven for 2 hours. To ensure comparability of degradation efficiencies between materials, the proportion of Ti in the coated material was kept constant. Therefore, the amounts of the other three materials varied, with TiO2 and TiO2 weighed separately. 2-x 6.64 mg (converted based on 50% TiO and 50% TiO2), TiO2@C 7.5 mg (converted based on 100% TiO2), TiO2@CW 7.5 mg (converted based on 100% TiO2), Pd (3wt.%) / C 7.5 mg.

[0065] The above-mentioned different materials were used to prepare the working electrode, with a platinum sheet as the counter electrode and an Ag / AgCl reference electrode as the reference electrode, forming a three-electrode system. The electrolyte in the cathode chamber consisted of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg L2O4 solution. -1 A florfenicol aqueous solution was used, with 50 mL of Na₂SO₄ aqueous solution in the anode chamber, to assemble a florfenicol H-type double-chamber sealed electrolytic cell degradation device. Electrochemical degradation was carried out under an applied voltage of -1.2 V. The final diagram is shown below. Figure 3 B shows that the pseudo-first-order kinetic rate constant is calculated using the following formula: K = ln[(C t -C0) / C t ],Will Figure 3 A becomes Figure 3 B. The larger the pseudo-first-order kinetic rate constant of the material, the better its degradation efficiency. Since the Ti content of the compared materials is consistent, the TiO2@CW material has a good electrocatalytic degradation effect on florfenicol, demonstrating that the scheme of using BDC contained in alkali-reduced white mud to prepare electrode materials for pollutant degradation is feasible.

[0066] Example 4: Comparison of the degradation effect of TiO2@CW material on florfenicol under different temperature conditions

[0067] In this invention, TiO2@CW materials calcined at different temperatures prepared in the examples are used as the working electrode, a platinum sheet as the counter electrode, and an Ag / AgCl reference electrode as the reference electrode to form a three-electrode system. Na2SO4 is used as the electrolyte, and the system is finally assembled into a florfenicol H-type dual-chamber sealed electrolytic cell degradation device. The working electrode is prepared by the following method:

[0068] TiO2@CW calcined at different temperatures was synthesized under the same preparation conditions as in Example 2 (2), with the only difference being that the subsequent tube furnace calcination temperature was changed to 200 and 400℃. Subsequently, 7.5 mg of material and 10 μL of... Ink is formed by sonicating a mixture of 5wt% (BY-N169478-5ml), 4.5mL anhydrous ethanol, and 1.5mL isopropanol for at least 10 minutes. Under an infrared baking lamp, the ink is applied with a brush to pre-treated carbon paper (2cm × 2cm sheet carbon paper soaked in 0.5M H2SO4 and ultrasonically washed with deionized water and anhydrous ethanol). This amount is for one side only; both sides need to be coated. After coating all sides, place in a 60℃ vacuum drying oven for 2 hours.

[0069] The above-mentioned different materials were used to prepare the working electrode, with a platinum sheet as the counter electrode and an Ag / AgCl reference electrode as the reference electrode, forming a three-electrode system. The electrolyte in the cathode chamber consisted of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg L2O4 solution. -1 A florfenicol aqueous solution was used, with 50 mL of Na₂SO₄ aqueous solution in the anode chamber, to assemble a florfenicol H-type double-chamber sealed electrolytic cell degradation device. Electrochemical degradation was carried out under an applied voltage of -1.2 V. The final diagram is shown below. Figure 4 The pseudo-first-order kinetic rate constant is calculated using the following formula: K = ln[(C t -C0) / C t ], turning 4A into Figure 4 B. The larger the pseudo-first-order kinetic rate constant of the material, the better its degradation efficiency. The TiO2@CW material prepared at 400℃ has the best degradation effect, followed by 350℃, and the worst at 200℃.

[0070] Example 5: Study on the degradation performance of TiO2@CW material on florfenicol under different BDC:Ti source molar ratios. Other operations were the same as in Example 2 (2), the only difference being the change in the molar amount of Ti source. The molar ratio of BDC extracted from white mud to Ti source was 3:0.5; 3:1; 3:2; 3:5. For example, in the case of 3:1, 50 mL of the filtrate (containing 30.76% BDC) after shaking and filtration of white mud was added to a 100 mL hydrothermal reactor, and 0.19 mL of tetraisopropoxide was added under vigorous stirring to prepare the corresponding TiO2@CW material hydrothermally. For different Ti source ratios, 0.095, 0.19, 0.38, and 0.95 mL of tetraisopropoxide were added respectively. The above-mentioned materials with different molar ratios were used to prepare working electrodes. A platinum sheet was used as the counter electrode, and an Ag / AgCl reference electrode was used as the reference electrode to form a three-electrode system. The electrolyte in the cathode chamber consisted of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg L2SO4 solution. -1 The florfenicol aqueous solution was used as the basis, with 50 mL of Na₂SO₄ aqueous solution in the anode chamber, to assemble a florfenicol H-type double-chamber sealed electrolytic cell degradation device. Electrochemical degradation was carried out under an applied voltage of -1.2 V, such as... Figure 5 As shown, the pseudo-first-order kinetic rate constant is calculated using the following formula: K = ln[(C t -C0) / C t ],Will Figure 5 A becomes Figure 5B. The larger the pseudo-first-order kinetic rate constant of the material, the better its degradation efficiency. Materials with different molar ratios all showed good degradation effects on florfenicol, with the best molar ratio being 3:2. However, considering that the amount of Ti source added would increase economic costs, materials with a BDC:Ti source molar ratio of 3:1 are preferred without affecting the degradation effect.

[0071] Example 6: Investigation of the stability of TiO2@CW material for florfenicol degradation in step (2) of Example 2

[0072] The other operations are the same as in Example 1, the only difference being that the stability of TiO2@C and TiO2@CW materials was compared. Eight consecutive degradation experiments were conducted on both materials, each starting with a florfenicol concentration of 20-100 mg / L. -1 Degradation begins. The above materials are used to prepare the working electrode, with a platinum sheet as the counter electrode and an Ag / AgCl reference electrode as the reference electrode, forming a three-electrode system. The electrolyte in the cathode chamber consists of 40 mL of 50 mM Na₂SO₄ aqueous solution and 10 mL of 100 mg L⁻¹ electrolyte. -1 The florfenicol aqueous solution was used as the basis, with 50 mL of Na₂SO₄ aqueous solution in the anode chamber, to assemble a florfenicol H-type double-chamber sealed electrolytic cell degradation device. Electrochemical degradation was carried out under an applied voltage of -1.2 V, such as... Figure 6 As shown, TiO2@CW material exhibits excellent degradation efficiency in eight consecutive degradation cycles, while the degradation efficiency of TiO2@C material gradually decreases with increasing number of degradation cycles, indicating that TiO2@CW material has good stability.

[0073] Example 7: Effect of TiO2@CW material on florfenicol degradation under different pH conditions and in the presence of high concentrations of interfering substances. Other operations were the same as in Example 2, the only difference being that the amount of TiO2@CW material used was 7.5 mg, and the pH of the cathode chamber in the subsequent H-type dual-chamber sealed electrolytic cell degradation device was changed, and a high concentration of interfering substance (Cl) was added. - NO 3- HCO 3- SO3 2- The pH of the cathode chamber solution was adjusted using either 0.9 mM concentrated sulfuric acid or 0.9 mM sodium hydroxide. The material was prepared as the working electrode, with a platinum sheet as the counter electrode and an Ag / AgCl reference electrode as the reference electrode, forming a three-electrode system. The electrolyte in the cathode chamber consisted of 40 mL of 50 mM Na₂SO₄ aqueous solution and 10 mL of 100 mg L⁻¹ electrolyte. -1 The florfenicol aqueous solution was used as the basis, with 50 mL of Na₂SO₄ aqueous solution in the anode chamber, to assemble a florfenicol H-type double-chamber sealed electrolytic cell degradation device. Electrochemical degradation was carried out under an applied voltage of -1.2 V, such as... Figure 7 As shown in A and B, the pseudo-first-order kinetic rate constant is calculated using the following formula: K = ln[(C t -C0) / C t The larger the pseudo-first-order kinetic rate constant of a material, the better its degradation efficiency. Figure 7 As shown in Figure A, the degradation effect of florfenicol is best at pH 3.88, while the degradation activity is inhibited at pH 9.74. Figure 7 As shown in Figure B, the material still exhibits good degradation activity even in the presence of high concentrations of interfering substances. This further demonstrates the stability of the material.

[0074] Example 8: Degradation ability of TiO2@CW material for different pollutants

[0075] The other operations are the same as in Example 3, the only difference being the change in the type of contaminant. The material is prepared as the working electrode, a platinum sheet is used as the counter electrode, and an Ag / AgCl reference electrode is used as the reference electrode, forming a three-electrode system. When the contaminant being degraded is levofloxacin (LFX), the electrolyte in the cathode chamber consists of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg L... -1 The device consists of an LFX aqueous solution and a 50 mL Na2SO4 aqueous solution in the anode chamber, assembled into a levofloxacin H-type dual-chamber sealed electrolytic cell degradation apparatus. When degrading the pollutant nitrofurantoin (NFZ), the electrolyte in the cathode chamber consists of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg LFX aqueous solution. -1 The device consists of an NF2 aqueous solution and 50 mL of Na2SO4 aqueous solution in the anode chamber, assembled into a furazolidone H-type double-chamber sealed electrolytic cell degradation device.

[0076] When the pollutant being degraded is metronidazole (MNZ), the electrolyte in the cathode chamber consists of 40 mL of 50 mM Na2SO4 aqueous solution and 10 mL of 100 mg L2O3 solution. -1 The MNZ aqueous solution was used as the composition, and 50 mL of Na2SO4 aqueous solution was added to the anode chamber to assemble a metronidazole H-type double-chamber sealed electrolytic cell degradation device. Under the above conditions, the pollutants were electrochemically degraded, and the results are as follows: Figure 8 As shown, the pseudo-first-order kinetic rate constant is calculated using the following formula: K = ln[(C t -C0) / C t The larger the pseudo-first-order kinetic rate constant of the material, the better its degradation efficiency. TiO2@CW material has a certain degradation effect on a variety of pollutants, not just florfenicol.

[0077] The high-performance liquid chromatography (HPLC) used in this experiment was a Thermos Scientific Ultimate 3000, with a GL Science INERTSIL ODS-SP 5UM 4.6×250mm column and a diode array detector. The specific HPLC method was as follows: column temperature was set to 30℃, and detection wavelength was set to 210nm. The mobile phase consisted of 40% methanol and 60% water (containing 0.05% formic acid), and the flow rate was set to 0.8 mL / min.

[0078] Preparation of the florfenicol standard curve: Dissolve 100 mg of florfenicol in a 1 L volumetric flask, then dilute to the mark (using water as the solvent). Sonicate until the florfenicol is completely dissolved, yielding 100 mg / L of standard curve. -1 Florfenicol standard solution: Take 0.2 mL, 0.5 mL, 1 mL, and 2 mL of florfenicol standard solution respectively into 10 mL centrifuge tubes, and dilute with deionized water to the 10 mL mark to obtain 2 mg / L. -1 5mg L -1 10mg L -1 20mg L -1 A florfenicol solution of a certain concentration was prepared. The solution was detected using the high-performance liquid chromatography (HPLC) method described above, and a standard curve for florfenicol was obtained by plotting the concentration against the peak area of ​​the HPLC chromatogram.

[0079] The Chenhua CHI660e electrochemical workstation was used to degrade florfenicol under constant potential. At the corresponding time points, 1 mL of sample was taken from the cathode chamber of the H-type bipolar chamber, filtered through a 0.22 μm filter membrane, and injected. The corresponding florfenicol concentration was calculated according to the standard curve.

Claims

1. A porous carbon derived from a titanium-based MOF from a white mud of a reduction of an alkaline printing dye, characterized in that The printing and dyeing alkali reduction white mud derived titanium-based MOF porous carbon is prepared according to the following method: S1: uniformly dispersing the printing and dyeing alkali reduction white mud in an organic solvent, fully oscillating, and filtering; the obtained filtrate is a terephthalic acid-containing solution; the organic solvent is a mixed solvent of N,N-dimethylformamide and methanol in a volume ratio of 1-8:1; The printing and dyeing alkali reduction white mud is obtained from the following process: after the polyester is singed, desizing is performed with NaOH, sodium sulfate, sodium tripolyphosphate, polyether-modified polydimethylsiloxane and oxalic acid, and then alkali reduction is performed with a NaOH solution; the obtained wastewater is adjusted to pH 3-5 for acid precipitation and is subjected to coagulation with polyferric sulfate and polyaluminum chloride; the obtained mixed liquid is dewatered by plate and frame filter press; and the obtained filter cake is the printing and dyeing alkali reduction white mud; S2: titanium tetraisopropoxide is added dropwise into the terephthalic acid-containing solution of step S1 under stirring, after dropping, stirring hydrolysis is performed for 1-4 h, and hydrothermal reaction is performed at 120-150 DEG C for 10-24 h; the obtained reaction liquid is separated and washed to obtain a titanium-based MOF; the molar ratio of terephthalic acid to the titanium tetraisopropoxide in the terephthalic acid-containing solution is 3:0.5-5; S3: the titanium-based MOF of step S2 is calcined at 200-400 DEG C for 1-3 h in a protective atmosphere to obtain the printing and dyeing alkali reduction white mud derived titanium-based MOF porous carbon TiO2@C-W.

2. The printing and dyeing alkali reduction white mud derived Ti-based MOF porous carbon according to claim 1, characterized in that: In step S1, the volume of the organic solvent is 30-100 mL / g based on the mass of the printing and dyeing alkali reduction white mud.

3. The printing and dyeing alkali-reduced white mud derived Ti-based MOF porous carbon according to claim 1, characterized in that: In step S1, the oscillation is performed in a multitube vortex mixer, and the oscillation conditions are as follows: 60 W, rotation speed of 2500 rpm, and oscillation time of 6-24 h.

4. The printing and dyeing alkali reduction white mud derived Ti-based MOF porous carbon according to claim 1, characterized in that: In step S2, the separation and washing are as follows: the reaction liquid is cooled to room temperature, centrifuged, the obtained precipitate is sequentially washed by centrifugation with DMF and methanol, and dried to obtain the titanium-based MOF; In step S3, the protective atmosphere is a nitrogen atmosphere.

5. A TiO2@C-W electrode prepared from the printing and dyeing alkali reduction white mud derived titanium-based MOF porous carbon according to claim 1.

6. The TiO2@C-W electrode of claim 5, wherein The TiO2@C-W electrode is prepared according to the following method: The TiO2@C-W material and 5 wt% Nafion are uniformly dispersed in a mixed solvent of anhydrous ethanol and isopropanol to obtain ink; the mass of the TiO2@C-W material to the volume of 5 wt% Nafion is 1 mg:1.33-2.66 μL; The ink is applied to both sides of the pretreated carbon paper, dried, and the TiO2@C-W electrode is obtained; the mass of the TiO2@C-W material is 0.2-1.875 mg / cm2 based on the area of a single side of the pretreated carbon paper 2 .

7. The TiO2@C-W electrode of claim 6, wherein The pretreated carbon paper is obtained according to the following method: soaking in 0.5 M H2SO4, ultrasonic washing with deionized water and anhydrous ethanol to obtain the pretreated carbon paper.

8. Application of the TiO2@C-W electrode according to claim 5 as a cathode material in electrochemical reduction degradation of antibiotic organic matter.

9. Use according to claim 8, wherein: The antibiotic organic matter is one or two or more of levofloxacin, furacillin, metronidazole and florfenicol.

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