Biocl / pedot:pss-based photocatalytic hydrogel with solvent effect and application

Abstract

The application discloses a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a solvent effect and application, wherein the BiOCl / PEDOT:PSS-based photocatalytic hydrogel is formed by dispersing BiOCl particles into a konjac glucomannan / polyvinyl alcohol / carrageenan network structure reinforced by PEDOT:PSS, and a multiple network interpenetrating structure is formed. The application utilizes an in-situ doping method to prepare a three-dimensional photocatalytic hydrogel system with high carrier transport efficiency. The three-dimensional macrostructure of the hydrogel can provide favorable conditions for sufficient fixation and uniform dispersion of the photocatalyst, and can help to expose more active sites of the catalyst; meanwhile, the highly dispersed photocatalyst has a large interface contact area with the three-dimensional hydrogel network, and can provide a large number of channels for carrier transport.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of water pollution purification, in particular to a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a solvent effect and application. BACKGROUND

[0002] With the acceleration of social development process, the discharge amount of various organic pollutants such as antibiotics, dyes and pesticides also increases year by year, which seriously pollutes water bodies and causes threats to human health and the environment. Photocatalysis is a simple water pollution treatment method, which can directly use sunlight as the only energy source to decompose organic pollutants into water and carbon dioxide, and is one of the promising methods in organic wastewater treatment. However, due to the limitations of the band gap structure, contact area and carrier separation of the material, the current photocatalyst is mainly applied in the form of nano powder, and the powder granular material is difficult to separate after use, which will cause high treatment cost and secondary pollution, hindering its practical application. Loading the powder photocatalyst into the hydrogel bulk material can solve the problem of difficult recovery of the photocatalyst, which is conducive to the recycling of the photocatalyst. Moreover, the adsorption of the hydrogel can also promote the photocatalytic degradation of the organic pollutants, realizing the synergistic purification effect of adsorption-photocatalysis. Among many hydrogel materials, biomass hydrogel has attracted widespread attention due to its excellent adsorption performance, wide source, green environmental protection and biodegradability. Loading the photocatalyst on the biomass hydrogel can effectively solve the problem of difficult recovery of the photocatalyst. However, due to the poor transport capacity of most biomass hydrogels for carriers, the catalytic performance of the biomass hydrogel photocatalytic system cannot meet the expected performance.

[0003] Therefore, developing green, efficient and stable photocatalytic macroscopic materials is still a difficult problem in the field of photocatalytic technology. SUMMARY

[0004] The application solves the technical problem of providing a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a solvent effect and application.

[0005] The purpose of the application is to provide a preparation method and application of a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a solvent effect.

[0006] In a first aspect, the application provides a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a solvent effect, wherein the BiOCl / PEDOT:PSS-based photocatalytic hydrogel is formed by dispersing BiOCl particles into a PEDOT:PSS-enhanced konjac glucomannan / polyvinyl alcohol / carrageenan network structure to form a multiple network interpenetrating structure.

[0007] In a second aspect, the present application provides a preparation method of a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect, and the steps are as follows:

[0008] Step 1: Bismuth nitrate pentahydrate and ethylene glycol were added into a beaker, stirred and dissolved to obtain solution A; potassium chloride and deionized water were added into a beaker, stirred and dissolved to obtain solution B; solution B was slowly added into solution A, stirred for a certain time, and then the mixed solution was transferred into a high-pressure reaction kettle for constant temperature reaction; after the reaction was completed, the product was extracted, washed and dried to obtain BiOCl.

[0009] Step 2: BiOCl, PEDOT:PSS and deionized water were added into a beaker and ultrasonically dispersed for a certain time; then polyvinyl alcohol was added, heated and stirred in a water bath for a certain time until it was completely dissolved, and then transferred into a constant temperature water bath.

[0010] Step 3: carrageenan was added into the uniform dispersion system obtained in step 2, stirred and reacted for a certain time, then konjac glucomannan was added, stirred for a certain time to form a solution colloid; the solution colloid was transferred into a mold, and the shaped gel was subjected to freeze-thaw cycle to improve its mechanical properties, and finally a BiOCl / PEDOT:PSS-based photocatalytic hydrogel product was obtained.

[0011] Preferably, in step 1, the mass ratio of bismuth nitrate pentahydrate, ethylene glycol, potassium chloride and deionized water is (0.4-3):(10-110):(0.1-2):(3-35).

[0012] Preferably, in step 1, the stirring time is 15-70 min.

[0013] Preferably, in step 1, the constant temperature reaction temperature is 140-200℃, and the constant temperature reaction time is 100-350 min.

[0014] Preferably, the mass ratio of BiOCl, PEDOT:PSS, deionized water and polyvinyl alcohol is (0.03-4):(0.001-0.015):(5-40):(0.1-1).

[0015] Preferably, in step 2, the ultrasonic dispersion time is 15-75 min, the water bath heating temperature is 60-90℃, and the stirring time is 15-50 min; the constant temperature water bath temperature is 15-28℃.

[0016] Preferably, in step 3, the mass ratio of BiOCl, PEDOT:PSS, deionized water, polyvinyl alcohol, carrageenan and konjac glucomannan is (0.03-4):(0.001-0.015):(5-40):(0.1-1):(0.1-1):(0.035-0.9).

[0017] Preferably, the first stirring time is 10-60 min, the second stirring time is 50-180 min, the freezing time is 2-8 h, the thawing time is 1-4 h, and the freezing-thawing cycle number is 3-8 times.

[0018] In a third aspect, the present application also relates to the application of the aforementioned BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect to sewage purification, and the application method is as follows:

[0019] (1) A target pollutant is configured into a pollutant solution.

[0020] (2) The pollutant solution is taken, BiOCl / PEDOT:PSS-based photocatalytic hydrogel is added under the action of magnetic stirring, and a photocatalytic degradation reaction is carried out under visible light irradiation, and after the reaction, the photocatalytic hydrogel is taken out, and the purified water body after removal of the pollutant is obtained.

[0021] (3) The used photocatalytic hydrogel is placed in ethanol for dehydration and self-purification treatment, and dry gel is obtained, and the dry gel is placed in deionized water to recover, and regenerated photocatalytic hydrogel is obtained, which can be directly used for the next photocatalytic degradation reaction.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) The present application uses an in-situ doping method to prepare a three-dimensional photocatalytic hydrogel system with high carrier transport efficiency. The three-dimensional macroscopic structure of the hydrogel can provide favorable conditions for the full fixation and uniform dispersion of the photocatalyst, which helps to expose more active sites of the catalyst; at the same time, the highly dispersed photocatalyst has a large interface contact area with the three-dimensional hydrogel network, which can provide a large number of channels for carrier transport. Secondly, the introduced conductive polymer PEDOT:PSS has strong charge transport capacity, which can build a fast path for carrier transport in the photocatalytic reaction, promote the directional migration of photo-generated charges and the efficient separation of carriers, and improve the photocatalytic activity. In addition, the conductive polymer PEDOT:PSS can form hydrogen bonds with the hydrogel system, improve the mechanical properties of the hydrogel, and enhance its practical applicability.

[0024] (2) The process used in the method has the characteristics of simplicity, cleanliness and environmental protection, the prepared composite photocatalytic hydrogel overcomes the key problem of difficult recovery of traditional powder catalyst, has excellent mechanical properties and adsorption-visible light photocatalytic synergistic removal of organic pollutants, and has solvent effect, simple regeneration method, excellent recycling performance, and wide application prospect in the field of actual organic wastewater purification, in addition, the introduced conductive polymer PEDOT:PSS has strong charge transport capacity, can build a fast path for the transport of carriers in photocatalytic reaction, promote the directional migration and efficient separation of photo-generated charges, and improve the photocatalytic activity. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 BiOCl / PEDOT:PSS-based photocatalytic hydrogel in ethanol dehydration, in deionized water in the process of recovery;

[0026] Figure 2 BiOCl / PEDOT:PSS-based photocatalytic hydrogel on rhodamine B adsorption-photocatalytic removal capacity;

[0027] Figure 3 Stress-strain curve of BiOCl / PEDOT:PSS-based photocatalytic hydrogel. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0029] The present embodiment relates to a preparation method of BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect, and the specific steps are as follows:

[0030] Embodiment 1

[0031] Step 1: In a beaker, add 1.2g bismuth nitrate pentahydrate and 40g ethylene glycol, stir to dissolve, get solution A; in a beaker, add 0.53g potassium chloride and 15g deionized water, stir to dissolve, get solution B; slowly add solution B to solution A, stir for 35min, then transfer the mixed solution to a high-pressure reaction kettle and react at 160℃ for 160min, after reaction, filter, wash and dry to get BiOCl.

[0032] Step 2, 0.18 g of BiOCl, 0.008 g of PEDOT:PSS and 25 g of deionized water were added into a beaker and ultrasonically dispersed for 20 min; then 0.5 g of polyvinyl alcohol was added, heated to 90°C in a water bath, and stirred for 15 min to completely dissolve, and then transferred to a 25°C constant temperature water bath.

[0033] Step 3, 0.35 g of carrageenan was added to the uniform dispersion system obtained in step 2, stirred for 35 min, then 0.3 g of konjac glucomannan was added, stirred for 140 min to form a solution colloid; the solution colloid was transferred to a mold, and the shaped gel was cycled 5 times for 5 h freezing and 2 h thawing to improve its mechanical properties, and finally a BiOCl / PEDOT:PSS-based photocatalytic hydrogel product was obtained.

[0034] Example 2

[0035] Step 1, 2.8 g of bismuth nitrate pentahydrate and 100 g of ethylene glycol were added into a beaker and stirred to dissolve to obtain solution A; 0.92 g of potassium chloride and 33 g of deionized water were added into a beaker and stirred to dissolve to obtain solution B; solution B was slowly added to solution A, stirred for 60 min, then the mixed solution was transferred to a high-pressure reaction kettle and reacted at 170°C for 120 min; after the reaction was completed, it was filtered, washed and dried to obtain BiOCl.

[0036] Step 2, 0.2 g of BiOCl, 0.015 g of PEDOT:PSS and 40 g of deionized water were added into a beaker and ultrasonically dispersed for 75 min; then 0.7 g of polyvinyl alcohol was added, heated to 85°C in a water bath, and stirred for 30 min to completely dissolve, and then transferred to a 27°C constant temperature water bath.

[0037] Step 3, 0.67 g of carrageenan was added to the uniform dispersion system obtained in step 2, stirred for 40 min, then 0.5 g of konjac glucomannan was added, stirred for 150 min to form a solution colloid; the solution colloid was transferred to a mold, and the shaped gel was cycled 8 times for 10 h freezing and 4 h thawing to improve its mechanical properties, and finally a BiOCl / PEDOT:PSS-based photocatalytic hydrogel product was obtained.

[0038] Example 3

[0039] Step 1, 0.5 g of bismuth nitrate pentahydrate and 15 g of ethylene glycol were added into a beaker and stirred to dissolve to obtain solution A; 0.15 g of potassium chloride and 5 g of deionized water were added into a beaker and stirred to dissolve to obtain solution B; solution B was slowly added to solution A, stirred for 15 min, then the mixed solution was transferred to a high-pressure reaction kettle and reacted at 140°C for 350 min; after the reaction was completed, it was filtered, washed and dried to obtain BiOCl.

[0040] Step 2, 0.06g BiOCl, 0.004g PEDOT:PSS and 18g deionized water were added into a beaker and ultrasonically dispersed for 15min; then 0.2g polyvinyl alcohol was added, heated to 70℃ in a water bath, and stirred for 50min to completely dissolve, and then transferred into a 18℃ constant temperature water bath.

[0041] Step 3, 0.2g carrageenan was added into the uniform dispersion system obtained in step 2, stirred for 20min, then 0.18g konjac glucomannan was added, stirred for 55min to form a solution colloid; the solution colloid was transferred into a mold, and the shaped gel was subjected to 3 cycles of freezing for 3h and thawing for 1h to improve its mechanical properties, and finally a BiOCl / PEDOT:PSS-based photocatalytic hydrogel product was obtained.

[0042] Example 4

[0043] Step 1, 0.89g bismuth nitrate pentahydrate and 28g ethylene glycol were added into a beaker and stirred to dissolve to obtain solution A; 0.3g potassium chloride and 10g deionized water were added into a beaker and stirred to dissolve to obtain solution B; solution B was slowly added into solution A, stirred for 25min, then the mixed solution was transferred into a high-pressure reaction kettle and reacted at 150℃ for 230min, after the reaction was completed, filtration, washing and drying were performed to obtain BiOCl.

[0044] Step 2, 0.08g BiOCl, 0.006g PEDOT:PSS and 23g deionized water were added into a beaker and ultrasonically dispersed for 20min; then 0.3g polyvinyl alcohol was added, heated to 80℃ in a water bath, and stirred for 40min to completely dissolve, and then transferred into a 20℃ constant temperature water bath.

[0045] Step 3, 0.33g carrageenan was added into the uniform dispersion system obtained in step 2, stirred for 25min, then 0.21g konjac glucomannan was added, stirred for 120min to form a solution colloid; the solution colloid was transferred into a mold, and the shaped gel was subjected to 3 cycles of freezing for 4h and thawing for 1h to improve its mechanical properties, and finally a BiOCl / PEDOT:PSS-based photocatalytic hydrogel product was obtained.

[0046] The BiOCl / PEDOT:PSS-based photocatalytic hydrogel prepared in examples 1-4 of the application was used for the application of adsorption-photocatalysis synergistic removal of pollutants, and the steps were as follows:

[0047] (1) 0.02g of target pollutants (such as rhodamine B, methylene blue, etc.) was taken to prepare a 20mg / L solution to obtain simulated pollutant wastewater.

[0048] (2) Take 50 mL of 20 mg / L simulated pollutant wastewater, with the aid of magnetic stirring, add BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a thickness of 2 mm and a diameter of 3.5 cm, adsorb for 30 min in the dark, and then place it under visible light for photocatalytic degradation reaction. Measure the pollutant concentration at regular intervals. After the reaction, remove the photocatalytic hydrogel to obtain purified water after removing pollutants.

[0049] (3) The adsorption-photocatalytic removal capacity of the BiOCl / PEDOT:PSS-based photocatalytic hydrogel prepared in Examples 1-4 for pollutants such as rhodamine B and methylene blue can reach 100%.

[0050] (4) The used photocatalytic hydrogel is placed in ethanol for dehydration and self-cleaning treatment to obtain dry gel. The dry gel is then placed in deionized water to restore it, and the regenerated photocatalytic hydrogel (as shown in Figure 1 ) can be directly used for the next photocatalytic degradation reaction.

[0051] The BiOCl / PEDOT:PSS-based photocatalytic hydrogel prepared in Example 1 was subjected to adsorption-photocatalytic performance test analysis, with rhodamine B as the target pollutant. The results are shown in Figure 2 Under visible light irradiation, the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with a thickness of 2 mm and a diameter of 3.5 cm can remove 100% of rhodamine B (50 mL, 20 mg / L).

[0052] The BiOCl / PEDOT:PSS-based photocatalytic hydrogel prepared in Example 1 was subjected to mechanical property test analysis. The results are shown in Figure 3 The addition of BiOCl and PEDOT:PSS can improve the mechanical properties of the hydrogel matrix.

[0053] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect, characterized in that: The BiOCl / PEDOT:PSS-based photocatalytic hydrogel is prepared by dispersing BiOCl particles into a PEDOT:PSS-enhanced konjac glucomannan / polyvinyl alcohol / carrageenan network structure to form a multi-layered interpenetrating network structure. The preparation method includes the following steps: S1. Add bismuth nitrate pentahydrate and ethylene glycol to a beaker, stir and dissolve to obtain solution A; add potassium chloride and deionized water to a beaker, stir and dissolve to obtain solution B; slowly add solution B to solution A, stir for a certain time, transfer the mixed solution to a high-pressure reactor for constant temperature reaction, filter after the reaction is completed, wash and dry to obtain BiOCl; S2. Add BiOCl, PEDOT:PSS and deionized water to a beaker and ultrasonically disperse for a certain time; then add polyvinyl alcohol, heat and stir in a water bath for a certain time to completely dissolve it, and then transfer to a constant temperature water bath. S3. Add carrageenan to the uniformly dispersed system obtained in step S2, stir and react for a certain time, then add konjac glucomannan and stir for a certain time to form a solution colloid; transfer the solution colloid to a mold, and perform a freeze-thaw cycle on the shaped gel to improve its mechanical properties, finally obtaining the BiOCl / PEDOT:PSS-based photocatalytic hydrogel product.

2. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S1, the mass ratio of bismuth nitrate pentahydrate, ethylene glycol, potassium chloride, and deionized water is (0.4~3):(10~110):(0.1~2):(3~35).

3. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S1, the stirring time is 15-70 minutes.

4. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S1, the constant temperature reaction temperature is 140~200℃, and the constant temperature reaction time is 100~350min.

5. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S2, the mass ratio of BiOCl, PEDOT:PSS, deionized water and polyvinyl alcohol is (0.03~4):(0.001~0.015):(5~40):(0.1~1).

6. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S2, the ultrasonic dispersion time is 15~75 min, the water bath heating temperature is 60~90℃, the stirring time is 15~50 min, and the constant temperature water bath temperature is 15~28℃.

7. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S3, the mass ratio of BiOCl, PEDOT:PSS, deionized water, polyvinyl alcohol, carrageenan, and konjac glucomannan is (0.03~4):(0.001~0.015):(5~40):(0.1~1):(0.1~1):(0.035~0.9).

8. The method for preparing the BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect according to claim 1, characterized in that: In step S3, the first stirring time is 10-60 min, the second stirring time is 50-180 min, the freezing time is 2-8 h, the thawing time is 1-4 h, and the freezing-thawing cycle is 3-8 times.

9. A BiOCl / PEDOT:PSS-based photocatalytic hydrogel with solvent effect as described in any one of claims 1-8, applied to water pollution purification, characterized in that: Specifically as follows: (1) Prepare a specific pollutant solution from the target pollutant; (2) Take the pollutant solution, add BiOCl / PEDOT:PSS-based photocatalytic hydrogel under magnetic stirring, and carry out photocatalytic degradation reaction under visible light irradiation. After the reaction, take out the photocatalytic hydrogel to obtain the purified water after removing the pollutants. (3) The used photocatalytic hydrogel is placed in ethanol for dehydration and self-purification treatment to obtain dry gel. The dry gel is then placed in deionized water to restore it, and the regenerated photocatalytic hydrogel can be directly used for the next photocatalytic degradation reaction.

Images