Defect-rich low-dimensional metal-based fenton catalyst, and preparation method and application thereof
By constructing defect-rich low-dimensional metal-based Fenton catalysts with defect structures on the surface of low-dimensional metal materials, the problems of iron sludge generation and narrow pH range in the traditional Fenton process are solved. This enables efficient catalytic degradation under visible light or dark conditions. The catalyst can be recycled and reused, reducing costs and operational difficulties.
Patent Information
- Application Number
- CN202611479073.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-22
- Publication Date
- 2026-11-06
AI Technical Summary
In existing technologies, the traditional Fenton process suffers from problems such as large iron sludge production, narrow pH range, high cost, difficult operation, and low degradation efficiency due to poor control of catalyst and hydrogen peroxide addition ratios. Furthermore, high-end photosensitive Fenton agents rely on imports and lack large-scale domestic supply.
A defect-rich, low-dimensional metal-based Fenton-like catalyst is used. By constructing defect structures such as oxygen vacancies, metal vacancies, and low-coordination metal sites on the surface of low-dimensional metal materials, active sites are formed, enhancing the activation ability of hydrogen peroxide. The catalyst can drive the Fenton-like reaction under visible light or dark conditions and can be recycled.
It achieves efficient catalytic degradation without iron or mud, has a wide pH range (2~9), high degradation efficiency, and the catalyst can be recycled, reducing operating costs and avoiding iron mud cleaning and equipment wear and tear. It has a wide range of applications.
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Figure CN123038798A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst technology, and particularly relates to a defect-rich low-dimensional metal-based Fenton catalyst, its preparation method, and its application. Background Technology
[0002] With rapid industrial development, industrial wastewater has become a severe challenge to the water environment. Among them, dye industry wastewater, due to its strong chemical stability, complex composition, high color, and high toxicity, has become a problem that urgently needs to be solved. Advanced oxidation technologies (AOPs) utilize highly oxidizing reactive oxygen species (ROSs) to attack organic matter, oxidizing and decomposing organic pollutants into carbon dioxide, water, and inorganic salts. It is an effective means of treating recalcitrant organic pollutants. Fenton and Fenton-like oxidation methods, as an important branch of AOPs, have been widely studied and applied due to their high efficiency and speed. However, the traditional homogeneous Fenton method has problems such as large iron sludge production, narrow pH range, and high cost, which limit its large-scale application.
[0003] Currently, the industry is rapidly shifting towards heterogeneous and photo-assisted Fenton systems. However, in practical applications, problems such as high cost, difficult operation, and low degradation efficiency caused by poor control of catalyst and hydrogen peroxide dosage and ratio remain challenges for enterprises. High-end photo-assisted Fenton agents are mostly imported, and there are no domestic large-scale suppliers of low-dimensional metal defect materials, leaving huge room for technological upgrading and market substitution.
[0004] Periyasamy et al. (Materials Advances, 2021, 2, 4843-4858) disclosed that the band gap of Fe3O4 / C was regulated by peroxy vacancies and used for visible light-Fenton degradation of RhB. After 180 min of visible light, the degradation rate of oxygen-rich vacancy sample M1 was 95.78%, while that of oxygen-free vacancy sample M2 was only 67.02%. This iron-based material is dependent on long-term light exposure and has the problem of iron sludge. The study also pointed out that even if the iron-based material has a defect structure, if the defect density is not properly controlled or the active sites are covered, the degradation rate will be affected.
[0005] The existing technique, *Magnetic-field-assisted pulsed laser ablation synthesis of Fe-O nanoparticles: Defect modulation and photo-Fenton degradation performance* (Applied Surface Science, 2026), discloses the preparation of defective Fe-O nanoparticles via magnetic field-assisted pulsed laser ablation for photo-Fenton degradation of crystal violet. The results show that even with increased defect density via a magnetic field, the degradation efficiency improvement is only 6%. The limited performance improvement is attributed to factors such as oxidant-limited kinetics and excess Fe. 2+ The study clearly attributes the failure of increased defect density to lead to significant performance improvement to the inherent limitations of iron-based systems, including the scavenging effect on free radicals and the photodegradation effect at high catalyst concentrations.
[0006] Therefore, developing a novel Fenton-like catalyst that is iron-free, mud-free, can be driven under multiple conditions, and can be recycled is of significant practical importance and market value. Summary of the Invention
[0007] The purpose of this invention is to provide a defect-rich, low-dimensional metal-based Fenton catalyst, its preparation method, and its application, thereby addressing the problems mentioned in the background art.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] On the one hand, the present invention provides a defect-rich low-dimensional metal-based Fenton catalyst, comprising a low-dimensional metal material matrix, wherein the surface of the low-dimensional metal material matrix has a defect structure;
[0010] The low-dimensional metallic material matrix is one or more of titanium-based materials and bismuth-based materials;
[0011] The defect structure is one or more of the following: oxygen vacancy, metal vacancy, low-coordination metal site, and lattice distortion.
[0012] On the other hand, the present invention provides a method for preparing a defect-rich, low-dimensional metal-based Fenton catalyst, comprising the following steps:
[0013] S1. Add the titanium source metal precursor and ligand or the bismuth source metal precursor and bromine source to the solvent, stir and mix evenly to obtain a reaction precursor mixture.
[0014] S2. The reaction precursor mixture is sealed and placed in an oven for heating and reaction.
[0015] S3. After the reaction is completed, the mixture is allowed to cool naturally, and then washed, dried, and ground to obtain a defect-rich, low-dimensional metal-based Fenton catalyst.
[0016] On the other hand, the present invention provides an application of a defect-rich, low-dimensional metal-based Fenton catalyst in the degradation of dye wastewater, comprising the following steps:
[0017] The defect-rich, low-dimensional metal-based Fenton catalyst was added to the reaction system containing dye wastewater and ultrasonically dispersed evenly. Hydrogen peroxide was added, and the catalytic degradation reaction was carried out under visible light irradiation or dark conditions. After the reaction was completed, the defect-rich, low-dimensional metal-based Fenton catalyst was recovered by precipitation and recycled.
[0018] Compared with the prior art, the specific beneficial effects of the present invention are as follows:
[0019] This invention utilizes a defect engineering strategy to construct defect structures on the surface of low-dimensional metallic materials, adjust the local electron configuration, effectively form active sites at the defects, and enhance the interaction between hydrogen peroxide and the material. This optimizes the charge transfer efficiency of the material and its activation ability for hydrogen peroxide at the atomic level.
[0020] The catalyst prepared by this invention does not require the addition of ferrous sulfate, and no iron sludge is produced during the reaction process, thus avoiding the problems of sludge cleaning and equipment wear and tear, and also eliminating the risk of color reversion caused by improper addition ratio of hydrogen peroxide and ferrous sulfate.
[0021] The catalyst prepared by this invention can drive Fenton-like reactions under visible light or dark conditions, and has a wide pH range (2~9), overcoming the narrow pH window defect of traditional Fenton technology.
[0022] The catalyst prepared by this invention can be directly recovered through precipitation and can be recycled after simple treatment. It has good cycle stability and helps to reduce operating costs.
[0023] The preparation method of this invention uses readily available and inexpensive raw materials, does not contain precious metals or harmful substances, is environmentally friendly, and is conducive to its promotion and application in industrial enterprises. Attached Figure Description
[0024] Figure 1 X-ray diffraction pattern of the defect-rich low-dimensional titanium-based catalyst prepared in Example 1 of this invention;
[0025] Figure 2 The X-ray photoelectron spectroscopy of the defect-rich low-dimensional titanium-based catalyst prepared in Example 1 of this invention;
[0026] Figure 3 A transmission electron microscope image of the defect-rich low-dimensional bismuth-based catalyst prepared in Example 2 of this invention;
[0027] Figure 4 The degradation performance curves of the defect-rich low-dimensional titanium-based catalyst on malachite green at different hydrogen peroxide concentrations in Example 3 of this invention are shown.
[0028] Figure 5 The degradation performance curve of Rhodamine B by the defect-rich low-dimensional bismuth-based catalyst in Example 4 of this invention is shown.
[0029] Figure 6 This is a performance diagram of catalyst recycling in Example 5 of the present invention. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0031] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.
[0032] Example 1: A defect-rich, low-dimensional titanium-based Fenton catalyst, the preparation method of which includes the following steps:
[0033] S1. Add 0.66 mmol phenylphosphonic acid and 2.3 mmol isonicotinic acid to 5.5 mL isopropanol and stir at 800 r / min until they are mixed evenly. Add 3 mmol isopropyl titanate and stir magnetically to obtain a mixture of reaction precursors.
[0034] S2. Transfer the reaction precursor mixture from step S2 to a 20 mL glass bottle, seal it with a rubber stopper and an aluminum cap, and then transfer it to an oven. Increase the temperature to 80 °C at a rate of 4 °C / min and react for 96 h.
[0035] S3. After the reaction is complete, the product obtained in S2 is filtered, washed several times with isopropanol, and then naturally dried in air for 24 h. It is then ground and collected to obtain a defect-rich low-dimensional metal-based Fenton catalyst.
[0036] The prepared catalyst was characterized by X-ray diffraction, and the results are as follows: Figure 1 As shown; characterization by X-ray photoelectron spectroscopy yielded the following results. Figure 2 As shown, Ti 2p exhibits two different chemical binding energy states, which completely correspond to the difference in electronic environment between the five-coordinate Ti1 and the six-coordinate Ti2 / Ti3 atoms in the crystal structure model, indicating that the catalyst successfully constructed a coordination defect structure.
[0037] Example 2: A defect-rich, low-dimensional bismuth-based Fenton catalyst, the preparation method of which includes the following steps:
[0038] S1. Add 2 mmol of bismuth nitrate pentahydrate and 2 mmol of potassium bromide to 30 mL of deionized water, stir to mix evenly, then add 2 M KOH aqueous solution dropwise, stir magnetically to mix completely, adjust the pH of the solution to 6, and obtain the reaction precursor mixture.
[0039] S2. Transfer the reaction precursor mixture to a 50 mL polytetrafluoroethylene-lined stainless steel high-pressure reactor, seal it, and then transfer it to an oven. Increase the temperature to 160 °C at a rate of 6 °C / min and react for 24 h.
[0040] S3. After the reaction is complete, the product is naturally cooled, centrifuged and collected, washed three times each with deionized water and anhydrous ethanol, and then dried in an oven at 60℃ for 12 h. The product is then ground and collected to obtain a defect-rich, low-dimensional bismuth-based Fenton catalyst.
[0041] The prepared catalyst was characterized by transmission electron microscopy, and the results are as follows: Figure 3 As shown, the catalyst exhibits an ultrathin nanosheet morphology.
[0042] Example 3: Application of defect-rich, low-dimensional titanium-based catalysts in the degradation of malachite green (MG):
[0043] Five mg of the defect-rich, low-dimensional titanium-based catalyst prepared in Example 1 was added to a quartz reactor containing 50 mL of malachite green (10 mg / L). The reactor was stirred at 800 rpm under dark conditions to allow the catalyst and contaminants to reach adsorption-desorption equilibrium. Hydrogen peroxide was added to achieve a concentration of 4–100 mmol / L. The reactor was then irradiated with visible light using a xenon lamp (λ>420 nm). Samples were taken at regular intervals, and after centrifugation, the absorbance of the supernatant at 617 nm was measured. The results are as follows: Figure 4 As shown, hydrogen peroxide at a low concentration of 4 mM can achieve complete degradation of MG within 50 minutes.
[0044] Example 4: Application of defect-rich, low-dimensional bismuth-based Fenton catalysts in the degradation of Rhodamine B:
[0045] 10 mg of the defect-rich, low-dimensional bismuth-based Fenton catalyst prepared in Example 2 was added to a quartz reactor containing 50 mL of Rhodamine B (10 mg / L). The reactor was stirred at 800 rpm for 30 minutes in the dark to allow the catalyst and contaminants to reach adsorption-desorption equilibrium. Hydrogen peroxide was added to a concentration of 10 mmol / L, and the reactor was irradiated with visible light using a xenon lamp (λ>420 nm). Samples were taken at regular intervals, and the absorbance of the supernatant at 554 nm was measured after centrifugation. The results are as follows: Figure 5As shown, after 18 minutes of reaction, the degradation rate of Rhodamine B reached over 95%.
[0046] Example 5, Catalyst Cyclic Stability Test:
[0047] The catalyst from the reaction in Example 3 was recovered by centrifugation precipitation, washed three times each with deionized water and anhydrous ethanol, dried at 60°C, and used for the next cycle experiment; the results are as follows: Figure 6 As shown, after five cycles, the catalyst maintained a degradation efficiency of over 90% for malachite green, indicating that the catalyst has good cycle stability.
[0048] In summary, this invention provides a defect-rich low-dimensional metal-based Fenton catalyst through a synergistic strategy of "iron-free low-dimensional metal + defect engineering". Compared with the prior art, it is iron-free, mud-free, can be driven under various conditions, can be recycled and reused, and its cycle stability can reach ≥90%.
[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A defect-rich, low-dimensional metal-based Fenton catalyst, characterized in that, It includes a low-dimensional metallic material matrix, wherein the surface of the low-dimensional metallic material matrix has a defect structure; The low-dimensional metallic material matrix is one or more of titanium-based materials and bismuth-based materials; The defect structure is one or more of the following: oxygen vacancy, metal vacancy, low-coordination metal site, and lattice distortion.
2. The defect-rich low-dimensional metal-based Fenton catalyst according to claim 1, characterized in that, The low-dimensional metallic material matrix is one or more of two-dimensional nanosheets, nanoribbons, or quantum dots.
3. The defect-rich low-dimensional metal-based Fenton catalyst according to claim 2, characterized in that, The titanium-based material is one or more of TiO2, titanium oxide clusters, and titanates; The bismuth-based material is one or more of BiOBr, BiOCl, and BiVO4.
4. A method for preparing a defect-rich, low-dimensional metal-based Fenton catalyst as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Add the titanium source metal precursor and ligand or the bismuth source metal precursor and bromine source to the solvent, stir and mix evenly to obtain a reaction precursor mixture. S2. The reaction precursor mixture is sealed and placed in an oven for heating and reaction. S3. After the reaction is completed, the mixture is allowed to cool naturally, and then washed, dried, and ground to obtain a defect-rich, low-dimensional metal-based Fenton catalyst.
5. The method for preparing the defect-rich low-dimensional metal-based Fenton catalyst according to claim 4, characterized in that, In S1, the titanium source metal precursor is one or more of isopropyl titanate, titanium tetrachloride, and tetrabutyl titanate; the bismuth source metal precursor is one or more of bismuth pentahydrate, bismuth nitrate, and bismuth chloride.
6. The method for preparing the defect-rich low-dimensional metal-based Fenton catalyst according to claim 4, characterized in that, In S1, the ligand is one or more of phenylphosphonic acid, isonicotinic acid, triphenylphosphine, hexadecyltrimethylammonium bromide, polyvinylpyrrolidone, and sodium dodecyl sulfate; the bromine source is potassium bromide; and the solvent is one or more of isopropanol, ethylene glycol, ethanol, and deionized water.
7. The method for preparing the defect-rich low-dimensional metal-based Fenton catalyst according to claim 4, characterized in that, In S1, when a bismuth source metal precursor and a bromine source are used, a step of adjusting the pH is also included.
8. The method for preparing the defect-rich low-dimensional metal-based Fenton catalyst according to claim 4, characterized in that, In S2, the heating rate of the heating reaction is 4~8℃ / min, the reaction temperature is 80~180℃, and the reaction time is 12~96 h.
9. The application of a defect-rich, low-dimensional metal-based Fenton catalyst as described in any one of claims 1-8 in the degradation of dye wastewater, characterized in that, Includes the following steps: The defect-rich, low-dimensional metal-based Fenton catalyst was added to the reaction system containing dye wastewater and ultrasonically dispersed evenly. Hydrogen peroxide was added, and the catalytic degradation reaction was carried out under visible light irradiation or dark conditions. After the reaction was completed, the defect-rich, low-dimensional metal-based Fenton catalyst was recovered by precipitation and recycled.
10. The application according to claim 9, characterized in that, The dye is one or more of Rhodamine B, methylene blue, methyl orange, and malachite green; the concentration of hydrogen peroxide is 0.5-10 mmol / L; the dosage of the defect-rich low-dimensional metal-based Fenton catalyst is 0.1-2 g / L; and the pH range of the reaction system is 2-9.