Light-driven ZnIn2S4 / reduced graphene oxide / melamine formaldehyde sponge motor, preparation method and application thereof

Abstract

The application discloses a light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor and a preparation method and application thereof, wherein the preparation method comprises the following steps: firstly, preparing graphene oxide; and then growing ZnIn2S4 / reduced graphene oxide on the surface of melamine formaldehyde sponge in situ. The prepared sponge motor can autonomously move in water under the condition of controlling the switch of a light source, and exhibits excellent photocatalytic performance. The application highlights its advantages in the field of water treatment, improves the contact efficiency with pollutants and photocatalytic performance, and utilizes the photothermal effect of reduced graphene oxide to autonomously move under visible light without additional stirring equipment, thereby reducing the water treatment cost. The sponge motor has a significant photocatalytic effect on Cr(VI), is easy to recycle and reuse, and shows great potential and broad prospects in practical application.

Description

Technical Field

[0001] This invention belongs to the field of photocatalysis, and specifically discloses a light-driven ZnIn2S4 / reduced graphene oxide / melamine formaldehyde sponge motor, its preparation method and application. Background Technology

[0002] In recent years, with rapid industrialization, large amounts of harmful pollutants have been discharged into the aquatic environment, leading to serious water pollution problems. Among these, wastewater containing dyes, heavy metal ions, and heavy oil poses a significant threat to aquatic ecosystems, flora and fauna, and human life. To effectively address these pollution problems, researchers have been continuously exploring new materials and methods.

[0003] In the treatment of dyes and heavy metal ions, photocatalysis has attracted widespread attention due to its advantages such as simple operation, energy saving, environmental friendliness, and high efficiency in removing pollutants. Compared with powdered photocatalysts, monolithic photocatalysts, such as aerogels or hydrogels, have enormous application potential in the field of photocatalysis. They are not only easy to recycle but also less likely to cause secondary pollution. However, existing aerogel photocatalysis processes usually require mechanical vibration or stirring to enhance the contact between the aerogel and harmful substances in the water. This method may damage the structure of the aerogel and has limited contact efficiency.

[0004] Meanwhile, new materials have been developed for heavy oil adsorption. For example, patent document CN115193409A discloses a graphene-modified melamine sponge as a heavy oil adsorption material. This modified melamine sponge achieves a significant improvement in overall thermal conductivity and rapid adsorption of heavy oil through the effective encapsulation of the melamine sponge skeleton by graphene. After reduction by heat treatment, this graphene oxide-based melamine sponge exhibits good mechanical properties and flame retardant characteristics. More importantly, it can remove adsorbed oil through mechanical extrusion under light, extrusion washing in light solvents, or a combination of both, thereby achieving material reuse and further reducing processing costs. This is of great significance for practical applications.

[0005] Furthermore, the development of self-driven smart materials has provided new ideas for the field of water treatment. Miniature motors, as a type of macroscopically sized self-driven smart material, can spontaneously move in response to external stimuli or provide driving force for other objects. In water, this material can automatically track, mix autonomously, and remove contaminants without the need for additional stirring devices, thus reducing water treatment costs. However, there are currently no research reports on the autonomous movement of light-driven aerogels or similar materials. Summary of the Invention

[0006] This invention provides a light-driven ZnIn2S4 / reduced graphene oxide / melamine formaldehyde sponge motor for water treatment, its preparation method, and its application. ZnIn2S4 / reduced graphene oxide is grown in situ on the surface of melamine formaldehyde sponge MF. By controlling the switching of the light source, the sponge motor can achieve autonomous movement in water.

[0007] The specific technical solution of this invention is as follows: A method for preparing a light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor specifically includes the following steps: S1: Preparation of graphene oxide; S2: The graphene oxide prepared in step S1 is ultrasonically dispersed in deionized water. After adding zinc source, indium source and sulfur source, it is ultrasonically dispersed again. Ascorbic acid is added and stirred to adjust the pH to 2.5. S3: Clean the oil stains off the surface of the melamine-formaldehyde sponge MF, immerse it in NaOH solution for alkaline treatment, and then wash and dry it; S4: Immerse the MF obtained in step S3 in the dispersion obtained in step S2, centrifuge to remove excess dispersion in the saturated MF channels, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h, then soak it in water for 24 h and dry it to obtain the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor.

[0008] In step S1, the preparation methods of the graphene oxide include the Hummers method, the Brodie method, and the Staudenmaier method.

[0009] In step S2, the zinc source is zinc nitrate or zinc chloride, the indium source is indium chloride and indium nitrate, and the sulfur source is thioacetamide. The molar ratio of the three elements—zinc source, indium source, and sulfur source—is (0.8-1.0):(1.9-2.2):(3.8-4.2), and the pH of the dispersion is adjusted to 2-7.

[0010] In step S2, the graphene oxide sample is ultrasonically dispersed in deionized water for 2 hours; after adding zinc source, indium source and sulfur source, it is ultrasonically dispersed for 1 hour; and ascorbic acid is added and stirred for 10 minutes.

[0011] In step S3, the oil stains on the surface of the melamine-formaldehyde sponge are cleaned with deionized water and anhydrous ethanol.

[0012] In step S4, the MF parameters for centrifugal impregnation saturation are 1500 r / min for 5 min.

[0013] A light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor prepared by the above method.

[0014] The above-mentioned light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor is applied in the field of photocatalysis, which enables the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor to dynamically photocatalyze Cr(VI) in a water environment under visible light, thereby further reducing the Cr(VI) content in the water.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: First, by in-situ growing ZnIn2S4 / reduced graphene oxide on the surface of melamine sponge (MF), a sponge motor was prepared that can move autonomously during the switching of the light source. This characteristic overcomes the problem that traditional monolithic photocatalysts cannot move autonomously in water, thereby improving the contact efficiency with pollutants and enhancing photocatalytic performance.

[0016] Secondly, this motor utilizes the photothermal effect of reduced graphene oxide (rGO) to achieve autonomous movement of the sponge motor under visible light irradiation by controlling the light source switch. This autonomous movement capability allows the sponge motor to automatically track, mix, and remove pollutants from the water without the need for additional stirring or oscillation equipment, thus reducing water treatment costs.

[0017] Furthermore, the ZnIn2S4 / reduced graphene oxide / melamine sponge motor prepared in this invention exhibits high photocatalytic activity. Under visible light, the motor demonstrates excellent self-driving performance, enabling it to rapidly and effectively degrade harmful pollutants in water. Simultaneously, due to the easy recyclability of the melamine sponge, the motor is easily separated and recycled from the aquatic environment after use, avoiding secondary pollution problems.

[0018] In summary, the ZnIn2S4 / reduced graphene oxide / melamine sponge motor and its preparation method provided by this invention have significant beneficial effects in the field of water treatment. It not only solves the problem of traditional monolithic photocatalysts being unable to move autonomously in water, but also improves photocatalytic performance, reduces water treatment costs, and is easy to recycle and reuse. Therefore, this technology has great potential and broad prospects in practical applications. Attached Figure Description

[0019] Figure 1 The image shows the SEM spectrum of the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor in Example 3.

[0020] Figure 2 The graph shows the speed of movement of visible light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motors of different sizes in water in Example 3.

[0021] Figure 3This is an optical photograph of the visible light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor moving in water in Example 3.

[0022] Figure 4 The graph shows the photocatalytic performance of the ZnIn2S4 / reduced graphene oxide / melamine sponge motor for Cr(VI) under visible light drive in Examples 1-5.

[0023] Figure 5 The graph shows the cycle performance of the ZnIn2S4 / reduced graphene oxide / melamine sponge motor driven by visible light in Example 3. Detailed Implementation

[0024] The technical solution of the present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. It should be noted that those skilled in the art can easily understand the structural design principle of the present invention, and those skilled in the art can make any modifications or alterations to the present invention, but other instances obtained without creative effort are all within the scope of protection of the present invention.

[0025] Example 1 Step 1: Transfer 10 mL of concentrated H2SO4 to a 100 mL three-necked flask, add 2 g of natural flake graphite, stir thoroughly, then add 1 g of K2S2O8 and 1 g of P2O5 to the mixture, stir evenly in an ice-water bath at 0°C, and then react in an 80°C constant temperature water bath for 6 h. Cool to room temperature, slowly add 100 mL of deionized water, vacuum filter and wash until neutral, and dry the resulting precipitate at 40°C. Mix 2 g of the dried pre-oxidized graphite powder with 46 mL of concentrated H2SO4 in an ice-water bath at 0°C, slowly add 6 g of KMnO4, maintain 180 r / min, react in a 35°C constant temperature water bath for 2 h, slowly add 92 mL of deionized water and 10 mL of H2O2 until bright yellow, centrifuge and wash until neutral, and dry the resulting precipitate at 60°C to obtain GO.

[0026] Step 2: Disperse 10 mg GO in 16.667 g deionized water and sonicate for 2 h. Then add 93 mg Zn(NO3)2·6H2O, 64 mg InCl3·4H2O, 40 mg thioacetamide (TAA), and 3.333 mL glycerol and stir for 1 h. Add 5 mg ascorbic acid and stir for 10 min to adjust the pH of the solution to 2.5.

[0027] Step 3: Cut the MF into 3×3×3 mm³ cubes, remove the oil stains from the surface of the MF with deionized water and anhydrous ethanol, dry it, and then put it into 5 mol L... -1The mixture was treated with NaOH solution for 1 hour, washed with deionized water until neutral, and dried at 60°C.

[0028] Step 4: Place the MF obtained in Step 3 into the dispersion in Step 30, centrifuge the saturated MF at 1500 r / min for 5 min to remove excess dispersion in the pores, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h. Soak the obtained sponge in water for 24 h, and then dry it at 60 ℃ to obtain the ZnIn2S4 / rGO / MF sponge motor.

[0029] Example 2 Step 1: Transfer 10 mL of concentrated H2SO4 to a 100 mL three-necked flask, add 2 g of natural flake graphite, stir thoroughly, then add 1 g of K2S2O8 and 1 g of P2O5 to the mixture, stir evenly in an ice-water bath at 0°C, and then react in an 80°C constant temperature water bath for 6 h. Cool to room temperature, slowly add 100 mL of deionized water, vacuum filter and wash until neutral, and dry the resulting precipitate at 40°C. Mix 2 g of the dried pre-oxidized graphite powder with 46 mL of concentrated H2SO4 in an ice-water bath at 0°C, slowly add 6 g of KMnO4, maintain 180 r / min, react in a 35°C constant temperature water bath for 2 h, slowly add 92 mL of deionized water and 10 mL of H2O2 until bright yellow, centrifuge and wash until neutral, and dry the resulting precipitate at 60°C to obtain GO.

[0030] Step 2: Disperse 6.667 mg GO in 16.667 g deionized water and sonicate for 2 h. Then add 93 mg Zn(NO3)2·6H2O, 64 mg InCl3·4H2O, 40 mg thioacetamide (TAA), and 3.333 mL glycerol and stir for 1 h. Add 5 mg ascorbic acid and stir for 10 min. Adjust the pH of the solution to 2.5.

[0031] Step 3: Cut the MF into 3×3×3 mm³ cubes, remove the oil stains from the surface of the MF with deionized water and anhydrous ethanol, dry it, and then put it into 5 mol L... -1 The mixture was treated with NaOH solution for 1 hour, washed with deionized water until neutral, and dried at 60°C.

[0032] Step 4: Place the MF obtained in Step 3 into the dispersion in Step 3, centrifuge the saturated MF at 1500 r / min for 5 min to remove excess dispersion in the pores, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h. Soak the obtained sponge in water for 24 h, and then dry it at 60 ℃ to obtain the ZnIn2S4 / rGO / MF sponge motor.

[0033] Example 3 Step 1: Transfer 10 mL of concentrated H2SO4 to a 100 mL three-necked flask, add 2 g of natural flake graphite, stir thoroughly, then add 1 g of K2S2O8 and 1 g of P2O5 to the mixture, stir evenly in an ice-water bath at 0°C, and then react in an 80°C constant temperature water bath for 6 h. Cool to room temperature, slowly add 100 mL of deionized water, vacuum filter and wash until neutral, and dry the resulting precipitate at 40°C. Mix 2 g of the dried pre-oxidized graphite powder with 46 mL of concentrated H2SO4 in an ice-water bath at 0°C, slowly add 6 g of KMnO4, maintain 180 r / min, react in a 35°C constant temperature water bath for 2 h, slowly add 92 mL of deionized water and 10 mL of H2O2 until bright yellow, centrifuge and wash until neutral, and dry the resulting precipitate at 60°C to obtain GO.

[0034] Step 2: Disperse 5 mg GO in 16.667 g deionized water and sonicate for 2 h. Then add 93 mg Zn(NO3)2·6H2O, 64 mg InCl3·4H2O, 40 mg thioacetamide (TAA), and 3.333 mL glycerol and stir for 1 h. Add 5 mg ascorbic acid and stir for 10 min to adjust the pH of the solution to 2.5.

[0035] Step 3: Cut the MF into 3×3×3 mm³ cubes, remove the oil stains from the surface of the MF with deionized water and anhydrous ethanol, dry it, and then put it into 5 mol L... -1 The mixture was treated with NaOH solution for 1 hour, washed with deionized water until neutral, and dried at 60°C.

[0036] Step 4: Place the MF obtained in Step 3 into the dispersion in Step 30, centrifuge the saturated MF at 1500 r / min for 5 min to remove excess dispersion in the pores, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h. Soak the obtained sponge in water for 24 h, and then dry it at 60 ℃ to obtain the ZnIn2S4 / rGO / MF sponge motor.

[0037] Example 4 Step 1: Transfer 10 mL of concentrated H2SO4 to a 100 mL three-necked flask, add 2 g of natural flake graphite, stir thoroughly, then add 1 g of K2S2O8 and 1 g of P2O5 to the mixture, stir evenly in an ice-water bath at 0°C, and then react in an 80°C constant temperature water bath for 6 h. Cool to room temperature, slowly add 100 mL of deionized water, vacuum filter and wash until neutral, and dry the resulting precipitate at 40°C. Mix 2 g of the dried pre-oxidized graphite powder with 46 mL of concentrated H2SO4 in an ice-water bath at 0°C, slowly add 6 g of KMnO4, maintain 180 r / min, react in a 35°C constant temperature water bath for 2 h, slowly add 92 mL of deionized water and 10 mL of H2O2 until bright yellow, centrifuge and wash until neutral, and dry the resulting precipitate at 60°C to obtain GO.

[0038] Step 2: Disperse 4 mg GO in 16.667 g deionized water and sonicate for 2 h. Then add 93 mg Zn(NO3)2·6H2O, 64 mg InCl3·4H2O, 40 mg thioacetamide (TAA), and 3.333 mL glycerol and stir for 1 h. Add 5 mg ascorbic acid and stir for 10 min to adjust the pH of the solution to 2.5.

[0039] Step 3: Cut the MF into 3×3×3 mm³ cubes, remove the oil stains from the surface of the MF with deionized water and anhydrous ethanol, dry it, and then put it into 5 mol L... -1 The mixture was treated with NaOH solution for 1 hour, washed with deionized water until neutral, and dried at 60°C.

[0040] Step 4: Place the MF obtained in Step 3 into the dispersion in Step 30, centrifuge the saturated MF at 1500 r / min for 5 min to remove excess dispersion in the pores, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h. Soak the obtained sponge in water for 24 h, and then dry it at 60 ℃ to obtain the ZnIn2S4 / rGO / MF sponge motor.

[0041] Example 5 Step 1: Transfer 10 mL of concentrated H2SO4 to a 100 mL three-necked flask, add 2 g of natural flake graphite, stir thoroughly, then add 1 g of K2S2O8 and 1 g of P2O5 to the mixture, stir evenly in an ice-water bath at 0°C, and then react in an 80°C constant temperature water bath for 6 h. Cool to room temperature, slowly add 100 mL of deionized water, vacuum filter and wash until neutral, and dry the resulting precipitate at 40°C. Mix 2 g of the dried pre-oxidized graphite powder with 46 mL of concentrated H2SO4 in an ice-water bath at 0°C, slowly add 6 g of KMnO4, maintain 180 r / min, react in a 35°C constant temperature water bath for 2 h, slowly add 92 mL of deionized water and 10 mL of H2O2 until bright yellow, centrifuge and wash until neutral, and dry the resulting precipitate at 60°C to obtain GO.

[0042] Step 2: Disperse 3.333 mg GO in 16.667 g deionized water and sonicate for 2 h. Then add 93 mg Zn(NO3)2·6H2O, 64 mg InCl3·4H2O, 40 mg thioacetamide (TAA), and 3.333 mL glycerol and stir for 1 h. Add 5 mg ascorbic acid and stir for 10 min. Adjust the pH of the solution to 2.5.

[0043] Step 3: Cut the MF into 3×3×3 mm³ cubes, remove the oil stains from the surface of the MF with deionized water and anhydrous ethanol, dry it, and then put it into 5 mol L... -1 The mixture was treated with NaOH solution for 1 hour, washed with deionized water until neutral, and dried at 60°C.

[0044] Step 4: Place the MF obtained in Step 3 into the dispersion in Step 30, centrifuge the saturated MF at 1500 r / min for 5 min to remove excess dispersion in the pores, then place it in a sealed sample bottle and keep it at 90 ℃ for 6 h. Soak the obtained sponge in water for 24 h, and then dry it at 60 ℃ to obtain the ZnIn2S4 / rGO / MF sponge motor.

[0045] Figure 1 The image shows the SEM spectrum of the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor in Example 3. Figure 1 As can be seen, rGO and ZIS grew on the melamine sponge skeleton in situ without changing the MF structure, and the rGO / MF was relatively uniformly dispersed.

[0046] Figure 2This is a graph showing the water velocity of ZnIn2S4 / reduced graphene oxide / melamine sponge motors of different sizes driven by visible light in Example 3. It can be seen that the five different sizes of ZnIn2S4 / reduced graphene oxide / melamine sponge motors can rise or fall in water with visible light on or off. When the sponge motor size is 3 mm, its self-driving speed is the highest, at 0.5 mm / s. -1 .

[0047] Figure 3 This is an optical photograph of the visible light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor moving in water in Example 3.

[0048] Figure 4 The graphs show the photocatalytic performance of the ZnIn2S4 / reduced graphene oxide / melamine sponge motor for Cr(VI) under visible light driven conditions in Examples 1-5 (Cr(VI) solution concentration: 50 mg / L, pH=7). The graphs show that the ZnIn2S4 / reduced graphene oxide / melamine sponge motor prepared in Example 3 exhibits the best photocatalytic effect on Cr(VI), reducing most of the Cr(VI) in the solution within 135 min, with a removal rate of 94%.

[0049] Figure 5 The graph shows the cycling performance of the ZnIn2S4 / reduced graphene oxide / melamine sponge motor under visible light drive in Example 3 (Cr(VI) solution concentration: 50 mg / L, pH=7). The graph shows that after three photocatalytic cycles, the photocatalytic reduction efficiency of the ZnIn2S4 / reduced graphene oxide / melamine sponge motor for Cr(VI) under visible light drive still reaches 88%.

[0050] The ZnIn2S4 / reduced graphene oxide / melamine sponge motor provided by this invention exhibits significant advantages in the field of water treatment. By in-situ growing ZnIn2S4 / reduced graphene oxide on the surface of melamine sponge, the prepared sponge motor can move autonomously during the switching of the light source, overcoming the problem that traditional photocatalysts cannot move autonomously in water, thereby improving the contact efficiency with pollutants and photocatalytic performance. Furthermore, this motor utilizes the photothermal effect of reduced graphene oxide to achieve autonomous movement under visible light, eliminating the need for additional stirring equipment and reducing water treatment costs. Experimental results also show that this motor has excellent photocatalytic effects on Cr(VI) and is easy to recycle and reuse, demonstrating great potential and broad prospects for practical applications.

Claims

1. A method for preparing a light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor, characterized in that, The preparation method specifically includes the following steps: S1: Preparation of graphene oxide; S2: The graphene oxide prepared in step S1 is ultrasonically dispersed in deionized water. After adding zinc source, indium source and sulfur source, it is ultrasonically dispersed again. Ascorbic acid is added and stirred to adjust the pH to 2.

5. S3: Clean the oil stains off the surface of the melamine-formaldehyde sponge MF, immerse it in NaOH solution for alkaline treatment, and then wash and dry it; S4: The MF obtained in step S3 is immersed in the dispersion obtained in step S2, centrifuged to remove excess dispersion in the saturated MF channels, and then placed in a sealed sample bottle and kept at 90 °C for 6 h. After that, it is soaked in water for 24 h and dried to obtain a light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor. In step S4, the MF parameters for centrifugal impregnation saturation are 1500 r / min for 5 min.

2. The preparation method of the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor according to claim 1, characterized in that, In step S1, the methods for preparing the graphene oxide include the Hummers method, the Brodie method, and the Staudenmaier method.

3. The method for preparing the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor according to claim 1, characterized in that, In step S2, the zinc source is zinc nitrate or zinc chloride, the indium source is indium chloride and indium nitrate, and the sulfur source is thioacetamide. The molar ratio of the three elements—zinc source, indium source, and sulfur source—is (0.8-1.0):(1.9-2.2):(3.8-4.2), and the pH of the dispersion is adjusted to 2-7.

4. The method for preparing the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor according to claim 1, characterized in that, In step S2, the graphene oxide sample is ultrasonically dispersed in deionized water for 2 hours; after adding zinc source, indium source and sulfur source, it is ultrasonically dispersed for 1 hour; and ascorbic acid is added and stirred for 10 minutes.

5. The method for preparing the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor according to claim 1, characterized in that, In step S3, the oil stains on the surface of the melamine-formaldehyde sponge are cleaned with deionized water and anhydrous ethanol.

6. A light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor prepared by any one of the preparation methods described in claims 1-5.

7. An application of the light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor as described in claim 6 in the field of photocatalysis, characterized in that, The light-driven ZnIn2S4 / reduced graphene oxide / melamine sponge motor is used to dynamically photocatalyze Cr(VI) in a visible light environment, further reducing the Cr(VI) content in the water.

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