A GO / MXene-Fe 2+ Two-dimensional composite thin film heterogeneous photo-Fenton catalysts, their preparation methods and applications

Abstract

The application discloses a GO / MXene two-dimensional composite film heterogeneous photo-Fenton catalyst and a preparation method and application thereof, wherein MXene and graphene oxide (GO) are mixed in proportion, then a mixed dispersion liquid is uniformly dropped and coated onto a surface of a filter paper substrate soaked with a solution by using a drop coating method, and a GO / MXene two-dimensional composite film is obtained through drying; the obtained two-dimensional composite film is added into a dye solution; a solution is added into a dye wastewater system, a xenon lamp is started to simulate visible light for continuous irradiation, and a photo-Fenton degradation reaction is started. The catalyst is a self-supporting film, is easy to recycle, does not generate a large amount of iron sludge, greatly reduces secondary pollution, is suitable for deep treatment of actual textile printing and dyeing dye wastewater, and has an industrial application prospect.

Description

Technical Field

[0001] This invention relates to water treatment catalytic materials technology, specifically to a GO / MXene- Two-dimensional composite thin film heterogeneous photo-Fenton catalyst, its preparation method and application. Background Technology

[0002] The textile printing and dyeing industry continuously discharges large amounts of wastewater containing recalcitrant dyes. Water-soluble dyes possess strong biological toxicity after entering water bodies, and some dyes and degradation intermediates pose carcinogenic risks. Conventional coagulation sedimentation, physical adsorption, and biological methods cannot completely mineralize the chromophores of the dyes, resulting in effluent that fails to meet discharge standards. Fenton oxidation technology, as a classic advanced oxidation process, relies on… catalytic It generates strong oxidizing hydroxyl radicals, which can non-selectively oxidize and decompose organic dyes, resulting in excellent mineralization. However, the traditional homogeneous Fenton system has significant defects: (1) the effective reaction pH window is extremely narrow, and it is only suitable for strongly acidic environments, resulting in high costs for wastewater pretreatment and acidification; (2) a large amount of iron sludge solid waste is generated after the reaction, resulting in high costs for solid waste disposal and secondary pollution; (3) iron ions are dissolved and lost, and the catalyst cannot be recycled. Visible light-assisted photo-Fenton technology can improve the free radical yield and broaden the pH range of application, while heterogeneous photo-Fenton catalysts have become a research hotspot due to their recyclability and low metal ion dissolution. Existing single-component carbon-based or MXene-based Fenton catalysts have defects: single GO materials have severe photogenerated electron-hole recombination, resulting in low photocatalytic efficiency; pure MXene has insufficient adsorption and enrichment capacity for organic dyes. Existing binary composite carriers are mostly prepared by hydrothermal and high-temperature calcination processes, which have high energy consumption and complex preparation processes, making it difficult to scale up production; and most powder catalysts have difficulties in separation and recovery, limiting their application in actual wastewater treatment projects. Therefore, developing a heterogeneous photo-Fenton thin film catalyst that is simple to prepare, easy to recycle, applicable to a wide pH range, and capable of broadly degrading a variety of dyes is a technical challenge that urgently needs to be solved in the field of dyeing and printing wastewater treatment. Summary of the Invention

[0003] To overcome the common technical shortcomings of existing technologies, such as the narrow pH range of traditional homogeneous Fenton catalysts, the generation of iron sludge, and the non-recyclability of catalysts, as well as the high energy consumption in the preparation of existing powdered heterogeneous catalysts, the difficulty in recovery, the significant shortcomings in the catalytic performance of single materials, the weak resistance to water quality interference, and the poor versatility in dye degradation, this invention provides a GO / MXene- Two-dimensional composite thin-film heterogeneous photo-Fenton catalysts, their preparation methods, and applications. The aim is to provide a two-dimensional thin-film heterogeneous photo-Fenton catalytic system with synergistic structure, simple preparation, easy separation and reuse, wide pH adaptability, and broad-spectrum high efficiency. Simultaneously, a simplified preparation process and standardized dye wastewater treatment procedure are provided to address the practical need for low-cost, deep mineralization treatment of dyeing and printing wastewater.

[0004] This invention provides a GO / MXene- A method for preparing two-dimensional composite thin-film heterogeneous photo-Fenton catalysts, which will... MXene and graphene oxide (GO) were mixed in a certain proportion, and then the mixture was uniformly drop-coated onto a substrate using a drop-coating method. The solution-wetted filter paper substrate surface is dried to obtain the GO / MXene- Two-dimensional composite thin film heterogeneous photo-Fenton catalyst.

[0005] Furthermore, the aforementioned The mass ratio of MXene to graphene oxide is 1:9 to 9:1.

[0006] Furthermore, by wetting the back of the filter paper with deionized water, the two-dimensional composite film can be easily peeled off.

[0007] This invention also provides GO / MXene- prepared by the above method. A two-dimensional composite thin film heterogeneous photo-Fenton catalyst, which can be repeatedly recycled after being used in the photo-Fenton degradation reaction and washed.

[0008] This invention also provides the above-mentioned GO / MXene- The application of two-dimensional composite thin-film heterogeneous photo-Fenton catalysts involves adding the obtained two-dimensional composite thin-film heterogeneous photo-Fenton catalysts to dye solutions and adding them to dye wastewater systems. The solution is subjected to continuous irradiation with a xenon lamp to simulate visible light, initiating the photo-Fenton degradation reaction. The dye wastewater is suitable for various pH levels, with optimal catalytic degradation efficiency under weakly acidic conditions.

[0009] Furthermore, the dye is any one or more mixed dyes selected from methyl orange, methylene blue, and rhodamine B.

[0010] Beneficial effects: The catalytic material of this invention relies on GO, MXene and The synergistic effect of the ternary components significantly enhances catalytic performance. GO's ultra-large specific surface area allows for the pre-adsorption and enrichment of dye pollutants in water. MXene's excellent metallic conductivity rapidly separates photogenerated electron-hole pairs, suppressing ineffective carrier recombination. Stable coordination and fixation of Fe... 2+ Under visible light, hydrogen peroxide can be continuously activated to generate strong oxidizing hydroxyl radicals. Dye degradation follows a pseudo-second-order kinetic model, primarily through complete chemical oxidation and mineralization. This material overcomes the limitation of traditional Fenton dyes, which are only suitable for strongly acidic environments, maintaining stable catalytic activity in weakly acidic to weakly alkaline water bodies. It also exhibits good tolerance to coexisting anions in dyeing and printing wastewater, making it suitable for complex industrial dyeing and printing wastewater.

[0011] The accompanying preparation process of this invention is simplified and efficient, with room temperature solution preparation throughout and cross-linking molding completed only by low-temperature drying. It requires no high-energy-consuming equipment, uses readily available raw materials, has a short production process, and is easy to mass-produce industrially. The catalyst is an integrated self-supporting thin film structure that can be directly removed, recycled, and reused after the reaction. Relying on coordinate bonds for firm fixation, the amount of metal ion leaching is low, avoiding the generation of large amounts of hazardous iron sludge in the traditional Fenton system, significantly reducing the overall operating costs of wastewater acidification and solid waste disposal, and possessing significant economic and environmental advantages. Attached Figure Description

[0012] Figure 1 The GO / MXene- prepared in Example 1 of this invention SEM and EDS images of two-dimensional composite films.

[0013] Figure 2 This section compares the degradation performance under different synergistic catalytic systems.

[0014] Figure 3 This shows a comparison of degradation performance at different dye concentrations.

[0015] Figure 4 This shows a comparison of the degradation performance of dye solutions at different pH values.

[0016] Figure 5 This section compares the degradation performance of dye solutions under different interfering anions. Detailed implementation method: The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0017] This invention provides a GO / MXene- A method for preparing two-dimensional composite thin-film heterogeneous photo-Fenton catalysts, which will... MXene and graphene oxide (GO) are mixed at a mass ratio of 1:9 to 9:1, and then the mixture is uniformly drop-coated onto a substrate using a drop-coating method. The solution-wetted filter paper substrate surface was dried to obtain GO / MXene- Two-dimensional composite thin film; the specific preparation method is as follows: first, the substrate is pretreated, then qualitative filter paper is laid flat on a glass petri dish, and a solution prepared with ferrous sulfate is used. The solution thoroughly wets the filter paper, removing air bubbles between the filter paper and the petri dish; take 5 mg / mL GO solution and 5 mg / mL... The MXene solution was stirred and mixed evenly at a certain mass ratio to obtain a GO / MXene mixed dispersion; the mixed dispersion was then evenly drop-coated onto the wetting surface. The solution was applied to the filter paper substrate surface; the coated sample was placed in an oven and dried at 45℃ for 5 h to complete the ionic crosslinking reaction; then it was removed from the oven, and deionized water was dripped onto the back of the filter paper to wet it, yielding GO / MXene- Two-dimensional composite thin film catalyst.

[0018] GO / MXene- The application of a two-dimensional composite thin-film heterogeneous photo-Fenton catalyst involves adding the obtained two-dimensional composite thin-film heterogeneous photo-Fenton catalyst to a dye solution, wherein the dye is any one or more mixed dyes selected from methyl orange, methylene blue, and rhodamine B; and adding the catalyst to a dye wastewater system. The solution is then subjected to continuous irradiation with a xenon lamp to simulate visible light, thus initiating the photo-Fenton degradation reaction.

[0019] Example 1 A GO / MXene- Two-dimensional composite thin-film heterogeneous photo-Fenton catalyst, its preparation method and application, wherein the method is as follows: (1) MXene (5 mg / ml) dispersion and GO (5 mg / ml) solution were mixed uniformly at a ratio of 1:4, and then the mixture was evenly drop-coated onto a surface. The filter paper substrate surface wetted with solution was dried in a forced-air drying oven at 45°C for 5 hours to obtain GO / MXene- Two-dimensional composite thin films; (2) GO / MXene- Two-dimensional composite film, methyl orange (MO) dye solution (concentration 100 mg / L), The degradation was investigated using both solution and xenon lamp. Specifically, GO / MXene- Directly add to MO solution; add GO / MXene- Place and In a thoroughly mixed MO solution; The solution was thoroughly mixed with the MO solution and irradiated with a xenon lamp; the GO / MXene- Place and The MO solution was thoroughly mixed and then irradiated with a xenon lamp. A comparison of the degradation effects is shown in the figure below. Figure 2 .

[0020] Example 2 (1) GO / MXene- The preparation of the two-dimensional composite film is as described in step (1) of Example 1; (2) Prepare MO solutions of different concentrations, namely 50, 100, 200 and 300 mg / L, and then add the same amount of water. The solution was thoroughly mixed, and equal masses of GO / MXene were added. The composite films were placed in MO solutions of the same volume concentration but different concentrations and irradiated with a xenon lamp. The degradation effect comparison is shown in the figure below. Figure 3 .

[0021] Example 3 (1) GO / MXene- The preparation of the two-dimensional composite film is as described in step (1) of Example 1; (2) Prepare MO solutions with different pH values, each with a concentration of 100 mg / L, and pH values ​​of 3, 5, 7, 9, 11, and the original solution. Then add the same amount of [unclear - possibly a specific ingredient or solution]. The solution was thoroughly mixed, and equal masses of GO / MXene were added. The composite film was placed in MO solutions of the same concentration but different pH values ​​and irradiated with a xenon lamp. The degradation effect comparison is shown in the figure below. Figure 4 .

[0022] Example 4 (1) GO / MXene- The preparation of the two-dimensional composite film is as described in step (1) of Example 1; Prepare MO solutions containing different anions at a concentration of 100 mg / L. The interfering ions are as follows: , , and , will be the same The solution was added to the original solution along with different interfering ions, and mixed thoroughly. Equal masses of GO / MXene- were then added. The composite film was placed in the above MO solution and irradiated with a xenon lamp. The degradation effect comparison is shown in the figure below. Figure 5 .

Claims

1. A GO / MXene- A method for preparing a two-dimensional composite thin film heterogeneous photo-Fenton catalyst, characterized in that, Will MXene and graphene oxide (GO) were mixed in a certain proportion, and then the mixture was uniformly drop-coated onto a substrate using a drop-coating method. The solution-wetted filter paper substrate surface is dried to obtain the GO / MXene- Two-dimensional composite thin film heterogeneous photo-Fenton catalyst.

2. A GO / MXene- as described in claim 1 A method for preparing a two-dimensional composite thin film heterogeneous photo-Fenton catalyst, characterized in that, The The mass ratio of MXene to graphene oxide is 1:9 to 9:

1.

3. A GO / MXene- as described in claim 1 A method for preparing a two-dimensional composite thin film heterogeneous photo-Fenton catalyst, characterized in that, The two-dimensional composite film can be easily peeled off by wetting the back of the filter paper with deionized water.

4. GO / MXene prepared by the method according to any one of claims 1-3 Two-dimensional composite thin-film heterogeneous photo-Fenton catalyst, characterized in that, The catalyst can be reused after being used in the photo-Fenton degradation reaction and then rinsed.

5. The GO / MXene as described in claim 4 The application of two-dimensional composite thin film heterogeneous photo-Fenton catalysts is characterized by, The obtained two-dimensional composite thin film heterogeneous photo-Fenton catalyst was added to the dye solution; and then added to the dye wastewater system. The solution is then subjected to continuous irradiation with a xenon lamp to simulate visible light, thus initiating the photo-Fenton degradation reaction.

6. The GO / MXene as described in claim 5 The application of two-dimensional composite thin film heterogeneous photo-Fenton catalysts is characterized by, The dye is any one or more of the following: methyl orange, methylene blue, and rhodamine B.

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