CN108636137B - A kind of film composite material loaded with indium zinc sulfide and polyvinylidene fluoride and preparation method thereof - Google Patents

Abstract

The invention discloses a film composite material supporting indium zinc sulfide and polyvinylidene fluoride and a preparation method thereof, comprising the following steps: step 1, preparing an aqueous solution of zinc chloride, indium chloride tetrahydrate and thioacetamide; step 2, dissolving polyvinylpyrrolidone and polyvinylidene fluoride in N,N-dimethylacetamide; step 3, applying the precursor solution obtained in step 1 and the casting solution obtained in step 2 on two sides of the carbon felt respectively. The surface of the side is completely reacted under the condition of 80-160 DEG C, and the film composite material of the indium zinc sulfide and polyvinylidene fluoride loaded is obtained. The membrane composite material of the invention can continuously catalyze and degrade sewage; the indium zinc sulfide photocatalyst is supported on one side of the carbon felt support layer, and the PVDF film is supported on the other side of the carbon felt support layer, thereby realizing photocatalysis and The separation of the membrane separation process in space, the two processes will not affect each other.

Description

A kind of film composite material loaded with indium zinc sulfide and polyvinylidene fluoride and preparation method thereof

technical field

The invention belongs to the technical field of photocatalytic or photoelectric catalytic film composite materials, and particularly relates to a film composite material supporting indium zinc sulfide and polyvinylidene fluoride and a preparation method thereof.

Background technique

Indium zinc sulfide has great potential value in the fields of photocatalysis, charge storage, electrochemical recording, and thermoelectric applications, and has become a hot research material in recent years. Indium zinc sulfide has a suitable semiconductor band gap structure, has high photocatalytic activity under visible light, and has a variety of synthetic methods, easy to prepare, and has been widely used in photocatalytic degradation of refractory organic pollutants, photocatalytic hydrogen Catalytic reduction of carbon dioxide and selective catalytic oxidation, etc. However, the nano- or micro-scale powder indium-zinc sulfide photocatalyst is difficult to separate in sewage treatment.

Polyvinylidene fluoride (PVDF) is one of the most widely used membrane separation materials today. It has strong antioxidant activity, excellent chemical resistance, strong thermal stability, high mechanical strength, good film-forming properties and high wear resistance. Easy to process. PVDF membranes are often used in ultrafiltration, microfiltration and other processes in water treatment. At present, there are two main ways to couple PVDF membrane and photocatalytic process for sewage treatment: (1) supported photocatalytic membrane reactor; (2) suspended photocatalytic membrane reactor. The supported photocatalytic film is divided into film surface loading and bulk modification, but the PVDF film surface is very smooth, and it is difficult for the catalyst to be supported on its surface for a long time, and the photocatalytic doping into the PVDF film will significantly reduce the photocatalytic effect, and organic The membrane structure of the PVDF membrane material may be destroyed in the long-term photocatalytic reaction. For the suspended photocatalytic membrane reactor, the PVDF membrane is mainly used to trap and separate the catalyst, but the catalyst particles will block the membrane pores and further form a filter cake layer on the membrane surface, resulting in serious membrane fouling, resulting in a decrease in PVDF membrane flux.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a film composite material loaded with indium zinc sulfide and polyvinylidene fluoride and a preparation method thereof, so as to solve the above-mentioned technical problems. The membrane composite material of the invention can continuously catalyze degradation and filtration of sewage; the indium zinc sulfide photocatalyst is supported on one side of the carbon felt support layer, and the PVDF film is supported on the other side of the carbon felt support layer, which can realize photocatalysis and Membrane separation process is spatially separated, but the two processes are coupled together, and the two processes do not interact with each other.

To achieve the above object, the present invention adopts the following technical solutions:

A preparation method of a film composite material loaded with indium zinc sulfide and polyvinylidene fluoride, comprising the following steps:

Step 1, prepare an aqueous solution of zinc chloride, indium chloride tetrahydrate and thioacetamide to obtain a precursor solution;

Step 2, dissolving polyvinylpyrrolidone and polyvinylidene fluoride in N,N-dimethylacetamide to obtain a casting solution;

In step 3, the precursor solution obtained in step 1 and the casting solution obtained in step 2 are respectively coated on the surfaces of both sides of the carbon felt, and the reaction is completed at 80-160 ° C to obtain the supported indium zinc sulfide and polyvinylidene fluoride. Vinyl membrane composites.

Further, step 1 specifically includes, dissolving zinc chloride, indium chloride tetrahydrate and thioacetamide in deionized water, and the molar mass ratio of zinc chloride, indium chloride tetrahydrate and thioacetamide is 1: 2:6; adjust the pH of the prepared aqueous solution to 2-3.

Further, in step 2, the mass ratio of polyvinylpyrrolidone and polyvinylidene fluoride is 1:5.

Further, in step 2, at room temperature, polyvinylpyrrolidone and polyvinylidene fluoride are dissolved in N,N-dimethylacetamide under continuous stirring, and the stirring is continued until air bubbles are removed.

Further, step 3 also includes pretreatment of the carbon felt, and the specific steps include:

(1) The selected carbon felt is placed in acetone and soaked for 30-60 minutes, and rinsed with deionized water;

(2) placing the carbon felt treated in step (1) in dehydrated alcohol for 30-60 minutes, and rinsed with deionized water again;

(3) drying the carbon felt treated in step (2) at 60° C. for 4 hours.

Further, in step 3, the precursor solution is coated on the surface of the relatively rough side of the carbon felt, and the casting liquid is coated on the surface of the relatively smooth side of the carbon felt.

Further, step 3 specifically includes:

Step 3.1, evenly spray the precursor solution on the front of the pretreated carbon felt, and react at 80-160°C for 6-16 hours;

Step 3.2, rinse the surface of the carbon felt treated in step 3.1 with deionized water, and then vacuum dry it at 60°C for 6 hours;

Step 3.3, fix the carbon felt treated in step 3.2 with the back side up on the glass plate, and use a doctor blade to evenly coat the casting liquid on the back side of the carbon felt;

Step 3.4, placing the carbon felt treated in step 3.3 in clean water to obtain a membrane composite material;

Among them, the front side of the carbon felt is the rougher side, and the back side of the carbon felt is the smoother side.

A film composite material of indium zinc sulfide and polyvinylidene fluoride prepared by any of the above preparation methods, PVDF film coating, carbon felt layer and indium zinc sulfide adhesion layer; using the carbon felt layer as the support and conductive layer, The indium zinc sulfide adhesion layer and the PVDF film coating are respectively attached to the surfaces of both sides of the carbon felt layer.

Further, indium zinc sulfide is attached to the surface of the relatively rough side of the carbon felt, and polyvinylidene fluoride is attached to the surface of the relatively smooth side of the carbon felt.

An application of any of the above-mentioned membrane composite materials loaded with indium zinc sulfide and polyvinylidene fluoride, the membrane composite material is applied to the treatment of sewage.

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

The preparation method of the supported indium zinc sulfide and PVDF membrane composite material of the present invention uses carbon felt as a support layer, so that the surfaces on both sides of the carbon felt can be respectively attached to the indium zinc sulfide and PVDF membrane, and the photocatalysis and membrane separation process are realized in space. On the other hand, the two processes do not affect each other, but the two processes are cleverly coupled together for continuous photocatalytic or photoelectric catalytic reactions. In addition, as a conductive layer, carbon felt has a stable structure, good adsorption capacity and good conductivity, and can be used as an electrode for photoelectric catalysis.

The supported indium zinc sulfide and PVDF membrane composite material of the present invention can enable continuous catalytic degradation and filtration of sewage, and can treat pollutants in water while ensuring the filtration rate; photocatalytic degradation and sewage filtration are carried out at the same time, and the integration of sewage can be realized No interval is required for processing; indium zinc sulfide and polyvinylidene fluoride are respectively attached to both sides of the carbon felt template, which can prevent indium zinc sulfide from clogging the membrane pores and ensure the filtration rate. The membrane composite material of the present invention is applied to the treatment of sewage, and can perform continuous photocatalytic or photoelectric catalytic treatment.

Description of drawings

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

1 is a schematic cross-sectional structure diagram of a film composite material loaded with indium zinc sulfide and polyvinylidene fluoride according to the present invention;

Fig. 2 is the surface scanning electron microscope image of one side of carbon felt loaded with indium zinc sulfide in Fig. 1;

Fig. 3 is the scanning electron microscope picture of one side of carbon felt loaded PVDF film in Fig. 1;

In Figure 1, 1 is the PVDF film coating, 2 is the carbon felt layer, and 3 is the indium zinc sulfide adhesion layer.

Detailed ways

Referring to FIG. 1 to FIG. 3 , a method for preparing a film composite material loaded with indium zinc sulfide and polyvinylidene fluoride (PVDF) according to the present invention includes the following steps:

(1) Select carbon felt as the support and conductive layer of the membrane composite material. The size of the carbon felt is the same as that of the water treatment membrane module, and the selected carbon felt is pretreated. The amount of acetone and anhydrous ethanol in the pretreatment can be Just submerge the carbon felt, including:

The first step is to soak the carbon felt in acetone for 30-60 minutes, then rinse it with deionized water several times;

In the second step, the carbon felt is soaked in absolute ethanol for 30-60 minutes, and then rinsed several times with deionized water again;

In the third step, the washed carbon felt is dried at 60° C. for 4 hours to obtain a pre-treated ready-to-use carbon felt template.

(2) Preparation of casting liquid:

At room temperature, 3 g of polyvinylpyrrolidone (K.30) and 15 g of polyvinylidene fluoride (PVDF) were dissolved in 100 mL of N,N-dimethylacetamide (DMAC) under constant stirring overnight to remove air bubbles , to obtain the casting liquid.

(3) Prepare the precursor solution:

0.1363 g of zinc chloride, 0.5865 g of indium chloride tetrahydrate and 0.4508 g of thioacetamide were dissolved in 10-100 mL of deionized water, and the pH was adjusted to 2-3 by adding hydrochloric acid to obtain a precursor solution.

(4) Synthesis of membrane composites:

Using a robotic arm and an art airbrush, evenly spray the precursor solution prepared in step (3) on the front of the pretreated carbon felt in step (1), and then put the carbon felt into an airtight container without heat insulation, at 80 The reaction is carried out under the condition of ℃-160° for 6-16 hours. After the reaction was completed, the carbon felt was taken out, the surface of the carbon felt was rinsed with deionized water, and then vacuum-dried at 60° C. for 6 hours. Next, fix the carbon felt on the glass plate with the back side up, and use a doctor blade to evenly coat the casting liquid on the back of the carbon felt, and finally put it in clean water to obtain a film loaded with indium zinc sulfide and polyvinylidene fluoride (PVDF). composite material. Among them, the front side of the carbon felt is a relatively rough side, and the back side of the carbon felt is a relatively smooth side.

In step (4), the film casting solution can also be coated on the back of the carbon felt to obtain a PVDF film coating, and then the precursor solution is sprayed on the front of the carbon felt to carry out the above catalyst synthesis and loading process to finally obtain a membrane composite material.

Referring to FIG. 1, a film composite material of indium zinc sulfide and polyvinylidene fluoride prepared by the above preparation method adopts carbon felt as the support and conductive layer, and indium zinc sulfide and polyvinylidene fluoride are respectively attached to both sides of the carbon felt. surface; indium zinc sulfide is attached to the surface of the rougher side of the carbon felt, and polyvinylidene fluoride is attached to the surface of the smoother side of the carbon felt. Referring to Figure 2, it can be observed that a layer of indium zinc sulfide is attached to the surface of the carbon felt fiber, and even agglomerates are abundant. Referring to Figure 3, it can be observed that the PVDF membrane is attached to the surface of the carbon felt and has a large number of filtering pores.

An application of the above-prepared membrane composite material loaded with indium zinc sulfide and polyvinylidene fluoride, the membrane composite material is applied to the treatment of sewage.

Example 1

A preparation method of a loaded indium zinc sulfide and PVDF membrane composite material, comprising the following steps:

(1) Select 17cm×19cm carbon felt as the composite material template for pretreatment:

In the first step, soak the carbon felt in 200 mL of acetone for 30 minutes, then rinse it with deionized water;

In the second step, soak the carbon felt in 200 mL of absolute ethanol for 30 minutes, and then rinse it with deionized water again;

In the third step, the washed carbon felt is dried at 60°C for 4 hours.

(2) Preparation of casting liquid:

At room temperature, 3 g of polyvinylpyrrolidone (K.30) and 15 g of PVDF were dissolved in 100 mL of N,N-dimethylacetamide (DMAC) under constant stirring overnight to remove air bubbles.

(3) Precursor solution preparation:

0.1363 g of zinc chloride, 0.5865 g of indium chloride tetrahydrate and 0.4508 g of thioacetamide were dissolved in 10 mL of deionized water to prepare a precursor solution, and hydrochloric acid was added to adjust the pH to 2.

(4) Composite material synthesis:

Using a robotic arm and an art airbrush, the precursor solution was evenly sprayed on the front of the pretreated carbon felt, placed in an uninsulated sealed container, and reacted at 80°C for 6 hours. After the reaction, the carbon felt was taken out, the surface was rinsed with deionized water, and then vacuum-dried at 60° C. for 6 hours. Next, fix the carbon felt on the glass plate with the back side up, and use a doctor blade to evenly coat the casting liquid on the back of the carbon felt, and finally place it in clean water to obtain a carbon felt-based PVDF film coating.

Embodiment 2

A preparation method of a loaded indium zinc sulfide and PVDF membrane composite material, comprising the following steps:

(1) Select 17cm×19cm carbon felt as the composite material template for pretreatment:

The first step is to soak the carbon felt in 200 mL of acetone for 60 minutes, then rinse it with deionized water;

In the second step, soak the carbon felt in 200 mL of absolute ethanol for 60 minutes, and then rinse it with deionized water again;

In the third step, the washed carbon felt is dried at 60°C for 4 hours.

(2) Preparation of casting liquid:

At room temperature, 3 g of polyvinylpyrrolidone (K.30) and 15 g of PVDF were dissolved in 100 mL of N,N-dimethylacetamide (DMAC) under constant stirring overnight to remove air bubbles.

(3) Precursor solution preparation:

Dissolve 0.1363 g of zinc chloride, 0.5865 g of indium chloride tetrahydrate and 0.4508 g of thioacetamide in 20 mL of deionized water to prepare a precursor solution, and add hydrochloric acid to adjust the pH to 2.5.

(4) Composite material synthesis:

The carbon felt was fixed on the glass plate with the back side facing upward, and the casting liquid was uniformly coated on the back side of the carbon felt using a doctor blade, and then placed in clean water to obtain a carbon felt-based PVDF film coating. Then use a robotic arm and an art airbrush to evenly spray the precursor solution on the front of the pretreated carbon felt, put it into an uninsulated sealed container, and react at 100°C for 10 hours. After the reaction, the carbon felt was taken out, the surface was rinsed with deionized water, and then vacuum-dried at 60° C. for 6 hours.

Embodiment 3

A preparation method of a loaded indium zinc sulfide and PVDF membrane composite material, comprising the following steps:

(1) Select 17cm×19cm carbon felt as the composite material template for pretreatment:

In the first step, soak the carbon felt in 200 mL of acetone for 45 minutes, then rinse it with deionized water;

In the second step, soak the carbon felt in 200 mL of absolute ethanol for 45 minutes, and then rinse it with deionized water again;

In the third step, the washed carbon felt is dried at 60°C for 4 hours.

(2) Preparation of casting liquid:

At room temperature, 3 g of polyvinylpyrrolidone (K.30) and 15 g of PVDF were dissolved in 100 mL of N,N-dimethylacetamide (DMAC) under constant stirring overnight to remove air bubbles.

(3) Precursor solution preparation:

Dissolve 0.1363 g of zinc chloride, 0.5865 g of indium chloride tetrahydrate and 0.4508 g of thioacetamide in 50 mL of deionized water to prepare a precursor solution, and add hydrochloric acid to adjust the pH to 2.5.

(4) Composite material synthesis:

Using a robotic arm and an art airbrush, the precursor solution was evenly sprayed on the front of the pretreated carbon felt, placed in an uninsulated sealed container, and reacted at 120°C for 16 hours. After the reaction, the carbon felt was taken out, the surface was rinsed with deionized water, and then vacuum-dried at 60° C. for 6 hours. Next, fix the carbon felt on the glass plate with the back side up, and use a doctor blade to evenly coat the casting liquid on the back of the carbon felt, and finally place it in clean water to obtain a carbon felt-based PVDF film coating.

Embodiment 4

A preparation method of a loaded indium zinc sulfide and PVDF membrane composite material, comprising the following steps:

(1) Select 17cm×19cm carbon felt as the composite material template for pretreatment:

In the first step, soak the carbon felt in 200 mL of acetone for 30 minutes, then rinse it with deionized water;

In the second step, soak the carbon felt in 200 mL of absolute ethanol for 30 minutes, and then rinse it with deionized water again;

In the third step, the washed carbon felt is dried at 60°C for 4 hours.

(2) Preparation of casting liquid:

At room temperature, 3 g of polyvinylpyrrolidone (K.30) and 15 g of PVDF were dissolved in 100 mL of N,N-dimethylacetamide (DMAC) under constant stirring overnight to remove air bubbles.

(3) Precursor solution preparation:

0.1363 g of zinc chloride, 0.5865 g of indium chloride tetrahydrate and 0.4508 g of thioacetamide were dissolved in 100 mL of deionized water to prepare a precursor solution, and the pH value was adjusted to 3.

(4) Composite material synthesis:

The carbon felt was fixed on the glass plate with the back side facing upward, and the casting liquid was uniformly coated on the back side of the carbon felt using a doctor blade, and then placed in clean water to obtain a carbon felt-based PVDF film coating. Then use a robotic arm and an art airbrush to evenly spray the precursor solution on the front of the pretreated carbon felt, put it into an uninsulated sealed container, and react at 160°C for 10 hours. After the reaction, the carbon felt was taken out, the surface was rinsed with deionized water, and then vacuum-dried at 60° C. for 6 hours.

Claims (9)

1. A preparation method of a film composite material loaded with indium zinc sulfide and polyvinylidene fluoride is characterized by comprising the following steps:

step 1, preparing aqueous solutions of zinc chloride, indium chloride tetrahydrate and thioacetamide to obtain a precursor solution;

step 2, dissolving polyvinylpyrrolidone and polyvinylidene fluoride in N, N-dimethylacetamide to obtain a membrane casting solution;

step 3, respectively coating the precursor solution obtained in the step 1 and the casting solution obtained in the step 2 on the surfaces of two sides of a carbon felt, and completely reacting at the temperature of 80-160 ℃ to obtain the film composite material loaded with indium zinc sulfide and polyvinylidene fluoride;

the step 3 specifically comprises the following steps:

step 3.1, uniformly spraying the precursor solution on the front surface of the pretreated carbon felt, and reacting for 6-16 hours at the temperature of 80-160 ℃;

step 3.2, washing the surface of the carbon felt treated in the step 3.1 by deionized water, and then drying for 6 hours in vacuum at the temperature of 60 ℃;

3.3, fixing the carbon felt processed in the step 3.2 on a glass plate with the back face upward, and uniformly coating the casting solution on the back face of the carbon felt by using a film scraping knife;

step 3.4, placing the carbon felt treated in the step 3.3 in clear water to obtain a membrane composite material;

wherein, the front of the carbon felt is a rough surface, and the back of the carbon felt is a smooth surface.

2. The preparation method according to claim 1, wherein the step 1 specifically comprises dissolving zinc chloride, indium chloride tetrahydrate and thioacetamide in deionized water, wherein the molar mass ratio of the zinc chloride, the indium chloride tetrahydrate and the thioacetamide is 1:2: 6; adjusting the pH value of the prepared aqueous solution to 2-3.

3. The method according to claim 1, wherein in the step 2, the mass ratio of the polyvinylpyrrolidone to the polyvinylidene fluoride is 1: 5.

4. The method according to claim 1, wherein the step 2 is to dissolve polyvinylpyrrolidone and polyvinylidene fluoride in N, N-dimethylacetamide under continuous stirring at room temperature, and to continue stirring until bubbles are removed.

5. The preparation method of claim 1, wherein the step 3 further comprises pretreatment of the carbon felt, and the specific steps comprise:

(1) soaking the selected carbon felt in acetone for 30-60 minutes, and washing with deionized water;

(2) soaking the carbon felt treated in the step (1) in absolute ethyl alcohol for 30-60 minutes, and washing with deionized water again;

(3) and (3) drying the carbon felt treated in the step (2) for 4 hours at the temperature of 60 ℃.

6. The method according to claim 1, wherein in step 3, the precursor solution is coated on a relatively rough surface of the carbon felt, and the casting solution is coated on a relatively smooth surface of the carbon felt.

7. A film composite supporting indium zinc sulfide and polyvinylidene fluoride prepared by the preparation method according to any one of claims 1 to 6, comprising: a PVDF film coating (1), a carbon felt layer (2) and an indium zinc sulfide adhesion layer (3); the carbon felt layer (2) is used as a supporting and conducting layer, and the indium zinc sulfide adhesion layer (3) and the PVDF film coating (1) are respectively adhered to the surfaces of two sides of the carbon felt layer (2).

8. The indium zinc sulfide and polyvinylidene fluoride-loaded film composite of claim 7, wherein the indium zinc sulfide is attached to the rougher side surface of the carbon felt and the polyvinylidene fluoride is attached to the smoother side surface of the carbon felt.

9. Use of the indium zinc sulfide and polyvinylidene fluoride-loaded membrane composite of claim 7 or 8 in the treatment of wastewater.

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