A preparation method and application of fixed ternary nano-photocatalyst

Abstract

The invention discloses a method for preparing a fixed ternary nanometer photocatalyst, belonging to the technical field of photocatalysis and water treatment. The ternary nanometer photocatalyst is CuFeS 2 , the catalyst carrier matrix is ​​calcium alginate. The present invention fixes the photocatalyst in the nano-powder state in the macroporous gel, which helps the photocatalyst to achieve stable dispersion and reuse, and can achieve the separation and recycling of the photocatalyst without reducing the photocatalytic ability. In addition, the macroporous immobilized gel improves the efficiency of photocatalysis and substrate adsorption, and enhances the mass transfer inside the photocatalyst immobilized gel. The calcium alginate used in the present invention has the characteristics of high light transmittance, strong plasticity, and simple preparation, and can achieve the CuFeS 2 The immobilization of the catalyst can effectively improve the catalytic efficiency.

Description

Technical Field

[0001] The invention relates to a preparation method for fixing a ternary nanometer photocatalyst, and belongs to the technical field of photocatalysis and water treatment. Background Art

[0002] The deep treatment of refractory organic pollutants (organic chlorides, organophosphorus pesticides, aromatic nitrates) in wastewater has become a research hotspot. Common treatment methods include activated carbon adsorption, biological treatment technology and advanced chemical methods. Among them, the recently developed metal nano-photoconversion of organic pollutants in advanced chemical methods has attracted widespread attention due to its high selectivity, high reaction rate and milder reaction conditions.

[0003] Recently, ternary nanocrystals have shown good application prospects in sewage treatment due to their low toxicity, earth abundance and adjustable band gap. For example, the invention patent with application publication number CN109621988A discloses a sea urchin-shaped hollow structure nickel-copper-selenium ternary nanocatalytic material and its preparation method and application, and the nickel-copper-selenium ternary nanocatalytic material is used to reduce nitrobenzene series in water. Due to the limitations of the development of reactor design, the application of photocatalysis in large-scale treatment of wastewater pollutants is subject to certain restrictions. The morphology of nanocrystals is often powdery, and it is difficult to separate nanocrystals by general post-treatment methods, resulting in the loss and waste of catalysts, which not only reduces the photocatalytic efficiency, but also causes further damage to the environment. In addition, traditional immobilized reactors, such as high molecular polymers, quartz, silica gel, etc., cannot evenly disperse nanocrystals, resulting in a reduction in their specific surface area. The opaque physical properties of the immobilized material itself lead to a reduction in the effective reaction area of ​​the photocatalyst and a reduction in light intensity. For example, the invention patent with authorization announcement number CN107262087B discloses a CeO 2 / Bi 2 WO 6 / Pumice-supported catalyst and its preparation method. The catalyst uses pumice as a carrier, on which CeO is loaded 2 / Bi 2 WO 6 / Compliant with catalytic powder. However, the pumice carrier is opaque, and only the catalyst loaded on the surface of the carrier can be exposed to light, which reduces the effective reaction area. The invention patent with the authorization announcement number CN104084183B discloses a method for fixing a powdered photocatalyst. The carrier is an aluminum plate. The specific surface area of ​​the carrier is low, and the light source cannot be transmitted.

[0004] As an immobilization material with strong plasticity, excellent light transmittance and easily controllable morphology, gel matrix has received extensive attention from the scientific community. However, specialized equipment and complex processes have hindered the large-scale production of macroporous photocatalyst immobilized gels. In addition, the current photocatalyst immobilized macroporous gels are mainly block-shaped in morphology, while photocatalyst immobilized spherical gel beads can be more conveniently operated on fixed beds and fluidized beds compared to block gels, and even stimulate the design of new photocatalytic reactors. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a preparation method for fixing a ternary nanometer photocatalyst, that is, fixing a powdered photocatalyst in a macroporous gel, and then degrading nitrobenzene pollutants in water. This can not only achieve the separation and recycling of the photocatalyst, but also does not significantly reduce the photocatalytic ability, thereby effectively improving the degradation efficiency.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a method for preparing a ternary nanometer photocatalyst and immobilizing the same, which specifically comprises the following steps:

[0007] A method for preparing a fixed ternary nanometer photocatalyst comprises the following steps:

[0008] CuFeS 2 Dispersed in water, then ultrasonically treated, thickener added to water and stirred, surfactant and carbonate added to the solution to continue to obtain a solution containing microbubbles;

[0009] The solution containing microbubbles is squeezed out through a needle and added into a mixed solution containing metal salt and acid. After solidifying overnight in the solution, the gel is washed, dehydrated, and freeze-dried;

[0010] The thickener includes sodium alginate, gelatin, and sodium hydroxymethyl cellulose; the surfactant includes but is not limited to sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium glycocholate, and dioctyl sodium sulfosuccinate; the carbonate includes sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; the metal salt includes calcium chloride, zinc chloride, barium chloride, magnesium chloride, magnesium sulfate, and zinc sulfate; the acid includes formic acid, acetic acid, hydrochloric acid, and sulfuric acid.

[0011] Preferred CuFeS 2 The mass ratio of the surfactant to the thickener is 1-1:3-8, and the mass ratio of the surfactant to the carbonate is 1-4:1-9.

[0012] CuFeS is preferred 2 The mass ratio of surfactant to thickener is 1:3, and the mass ratio of surfactant to carbonate is 1:5.

[0013] Preferably, the inner diameter of the needle is 0.33-1.6 mm; the average diameter of the gel beads is 2.3-4.8 mm.

[0014] Preferably, the inner diameter of the needle is 0.33 mm; the average diameter of the gel beads is 2.3 mm.

[0015] The ternary nano photocatalyst CuFeS 2 The preparation method is as follows:

[0016] Under vacuum conditions, cuprous and ferric salts are mixed in an organic solvent to obtain solution A, and then the reaction atmosphere is switched to nitrogen, followed by continued heating and stirring; hexamethyldisilathioane is mixed with octadecene to obtain solution B, and solution B is reacted with solution A to obtain a precursor;

[0017] Sodium sulfide nonahydrate is dissolved in water and an organic solvent to obtain solution C. The precursor is mixed with solution C in a cyclohexane medium to obtain CuFeS 2 Ternary nanocrystals.

[0018] Preferably, the cuprous salt includes CuI, CuCl, CuBr, and the ferric salt includes FeCl 3 , Fe 2 (SO 4 ) 3 The organic solvent in the solution A includes oleylamine and oleic acid.

[0019] Preferably, the concentration of hexamethyldisilathane in the solution B is 0.6-1 mol / L; the organic solvent in the solution C includes dimethylformamide, dimethylacetamide, tetrahydrofuran, acetone, and acetonitrile;

[0020] The volume ratio of solution A to solution B is 1-9:1; the concentration of sodium sulfide nonahydrate in the solution C is 0.15-0.25 mol / L; the volume ratio of ultrapure water to organic solvent is 1:2-4;

[0021] The molar ratio of cuprous, ferric salt and hexamethyldisilathione is 1-10:1-10:20-30; the cuprous and ferric salts in solution A are 0.02-0.05 mol / L;

[0022] The heating and stirring refers to the reaction at 100°C to 220°C for 1-8h.

[0023] Preferably, the concentration of hexamethyldisilathione in solution B is 0.67 mol / L, the volume ratio of solution A to solution B is 9:1; the concentration of sodium sulfide nonahydrate in solution C is 0.2 mol / L; the volume ratio of ultrapure water to organic solvent is 1:3; the molar ratio of cuprous, ferric salt and hexamethyldisilathione is 1:1:2; and the concentration of cuprous and ferric salt in solution A is 0.35 mol / L.

[0024] A ternary nano photocatalyst obtained by any of the above contents is used for degrading nitrobenzene in industrial wastewater.

[0025] Catalytic experiment of photocatalyst in free state

[0026] Add 10mg CuFeS to the pressure tube 2 Catalyst, add 0.1-5mmol nitrobenzene, 0.05-1mL hydrazine hydrate (50% solution) and 0-3mL ethanol. After mixing by stirring (60s) and ultrasonic (30s), the sealed vial is irradiated for 0-4h in a light band with a peak value at 440-450nm under stirring at room temperature. After the reaction is completed, centrifuge at 13200rpm for 5min in a dark environment, and take the supernatant to detect the conversion rate of the reaction by gas chromatography.

[0027] Catalytic experiments of immobilized photocatalyst gel

[0028] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 0.05-1 mL of hydrazine hydrate (50% solution) and 0-3 mL of ethanol, shake slowly in an oscillator for 10 minutes, then add 0.1-5 mmol of nitrobenzene and seal the beaker. Under room temperature stirring, irradiate with a light source that reaches a peak at 440-450 nm for 0-4 hours. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the conversion rate of the reaction.

[0029] Repeated photocatalytic experiments of immobilized photocatalyst gel

[0030] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate solution (50% concentration) and 3 mL of ethanol, shake slowly in an oscillator for 10 minutes, then add 1 mmol of nitrobenzene and seal the beaker. Under stirring at room temperature, irradiate for 2 hours using a light source with a peak at 440-450 nm. After the reaction is completed, use a Buchner funnel to quickly separate the reaction solution and the gel, and use gas chromatography to detect the conversion rate of the reaction. After the gel is separated, soak it in 10 mL of ethanol solution (50% concentration), shake it slowly in a vibrator for 10 minutes, repeat the washing three times, and then reuse the immobilized gel. After 6 consecutive recycling runs, the efficiency of macroporous gel in degrading nitrobenzene has hardly decreased.

[0031] Beneficial effects:

[0032] 1. The present invention uses CuFeS 2As the key to plasmon-enhanced nanocatalysis, taking advantage of the high abundance of the earth and using cheap raw materials, the rapid photocatalytic degradation of nitrobenzene pollutants in wastewater was achieved. This method avoids secondary pollution and expensive precious metal catalysts in traditional reactions, has mild reaction conditions, strong sustainability, high safety, and rapid reaction, which is more in line with the requirements of green chemistry;

[0033] 2. The present invention uses calcium alginate as an immobilization carrier to fix the nano-photocatalyst in the macroporous gel, which is convenient for the separation and reuse of the catalyst; the immobilization method is simple and highly operable, and the immobilized photocatalyst gel has stable catalytic performance.

[0034] 3. The immobilized photocatalyst macroporous gel of the present invention has good light transmittance. The immobilized photocatalyst is evenly distributed in the gel, which increases the overall specific surface area, thereby effectively improving the efficiency of photocatalytic degradation of nitrobenzene and improving the wastewater treatment capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0036] Figure 1 The following is the reaction scheme of the present invention.

[0037] Figure 2 Schematic diagram of the photocatalyst and gels of different sizes in the present invention.

[0038] Figure 3 This is a schematic diagram of the reusability of the photocatalyst macroporous gel of the present invention.

[0039] Figure 4 It is the gas chromatography analysis chart of nitrobenzene and aniline of the present invention. DETAILED DESCRIPTION

[0040] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0041] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0042] Example 1

[0043] 1mmol CuI and 1mmol FeCl 3Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0044] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.3 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 60 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a 0.33 mm needle, and dripped with 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0045] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, then add 5 mmol of nitrobenzene and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the conversion rate of the reaction is 100%.

[0046] Example 2

[0047] 1mmol CuI and 1mmol FeCl3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0048] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.1 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 60 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0049] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 83%.

[0050] Example 3

[0051] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0052] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.6 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 60 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0053] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, then add 5 mmol of nitrobenzene and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the conversion rate of the reaction is 100%.

[0054] Example 4

[0055] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0056] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.6 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 60 mg sodium dodecyl sulfate and 0.6 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0057] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 77%.

[0058] Example 5

[0059] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 3 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0060] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.6 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 60 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0061] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, then add 5 mmol of nitrobenzene and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the conversion rate of the reaction is 100%.

[0062] Example 6

[0063] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 1 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0064] 0.1 g CuFeS 2 Dispersed in 20 mL ultrapure water, then sonicated for 30 min. Next, 0.6 g of sodium alginate was added to the above suspension and stirred overnight to obtain a uniform solution. 60 mg of sodium dodecyl sulfate was added and the solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a 0.33 mm inner diameter needle, and dripped with 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0065] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, then add 5 mmol of nitrobenzene and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 65%.

[0066] Example 7

[0067] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0068] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.6 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 100 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0069] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 87%.

[0070] Example 8

[0071] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0072] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.6 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 200 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a 1.3 mm inner diameter needle, and dripped with 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0073] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 66%.

[0074] Example 9

[0075] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0076] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.3 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 100 mg sodium dodecyl sulfate and 0.3 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.78 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0077] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect the reaction conversion rate of 86%.

[0078] Example 10

[0079] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C under vacuum and keep for 1 h to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep for 6 h. Under vigorous stirring, 2 mmol of hexamethyldisilathione is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0080] 0.1 g CuFeS 2 Disperse in 20 mL ultrapure water and then sonicate for 30 min. Next, add 0.2 g sodium alginate to the above suspension and stir overnight to obtain a uniform solution. Add 100 mg sodium dodecyl sulfate and 0.45 g NaHCO 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a 1.6 mm inner diameter needle, and dripped with 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0081] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, add 5 mmol of nitrobenzene, and seal the beaker. Under room temperature stirring, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the conversion rate of the reaction is 70%.

[0082] Comparative Example 1

[0083] 1mmol CuI and 1mmol FeCl 3 Dissolve in 27 mL of oleylamine and stir in a three-necked round-bottom flask to obtain solution A. Heat the mixture to 120 ° C and keep it for 2 h under vacuum to remove oxygen and moisture. Switch the reaction atmosphere to nitrogen, then raise it to 200 ° C and stir, and keep it for 8 h. Under vigorous stirring, 2 mmol of hexamethyldisilathane is dissolved in 3 mL of 1-octadecene (ODE) to obtain solution B, which is quickly injected into the above mixture and the temperature is maintained at 200 ° C for 30 min. The solution is cooled to room temperature, toluene and ethanol are added to the reaction mixture, kept at 1000 rpm for 10 min, and then the precipitate is washed with a mixture of ethanol and toluene and dried under reduced pressure at 60 ° C. 0.1 g of sodium sulfide nonahydrate is dissolved in 5 mL of ultrapure water, and then 15 mL of dimethylformamide is added to obtain solution C. The dried precipitate is dispersed in 10 mL of cyclohexane, then mixed with solution C, and stirred at room temperature for 60 min. The mixture was centrifuged at 13200 rpm for 5 min, and the precipitate was washed with ethanol, which was repeated three times, and finally dried under reduced pressure at 60° C. Before use, the catalyst was fully ground into powder.

[0084] 0.1 g CuFeS 2 Disperse in 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, add 5 mmol of nitrobenzene in the reaction bottle. Under stirring at room temperature, irradiate for 4 hours using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the conversion rate of the reaction is 100%.

[0085] Comparative Example 2

[0086] 0.6 g of sodium alginate was added to the above suspension in 20 mL of ultrapure water and stirred overnight to obtain a homogeneous solution. 100 mg of sodium dodecyl sulfate and 0.3 g of NaHCO were added. 3 The solution was stirred continuously for about 2 h. The solution containing microbubbles was transferred to a syringe, squeezed out through a needle with an inner diameter of 0.33 mm, and dripped with a solution containing 10% (w / v) CaCl 2 and 10% (v / v) CH 3 After the gel was solidified overnight in the solution, the porous beads were washed several times with pure water to remove unreacted CaCl 2 and CH 3 COOH, and then kept under vacuum for 5 min. Finally, the macroporous gel was freeze-dried for 36 h.

[0087] Take 30 mg of freeze-dried gel beads and add them to a beaker, add 1 mL of hydrazine hydrate (50% solution) and 3 mL of ethanol, shake slowly in an oscillator for 10 min, then add 5 mmol of nitrobenzene and seal the beaker. Under stirring at room temperature, irradiate for 4 h using a light source with a peak at 440-450 nm. Take out 100 μL of sample solution regularly, extract with ethyl acetate, and use gas chromatography to detect that the nitrobenzene consumption is 2%.

Claims

1. A method for preparing a ternary nano-photocatalyst immobilization, Features: The following steps are involved: CuFeS 2 Dispersed in water, then ultrasonically treated, thickener added to water and stirred, surfactant and sodium bicarbonate added to the solution to continue to obtain a solution containing microbubbles; The solution containing microbubbles is squeezed out through a needle and added into a mixed solution containing metal salt and acid. After solidifying overnight in the solution, the gel is washed, dehydrated, and freeze-dried; The CuFeS 2 The mass ratio of the surfactant to the thickener is 1:3-8, and the mass ratio of the surfactant to sodium bicarbonate is 1-4:1-9; The thickener is sodium alginate; the surfactant is selected from sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium glycocholate, and dioctyl sodium sulfosuccinate; the metal salt is calcium chloride; and the acid includes formic acid, acetic acid, hydrochloric acid, and sulfuric acid.

2. The preparation method according to claim 1, Features: CuFeS 2 The mass ratio of surfactant to thickener is 1:3, and the mass ratio of surfactant to sodium bicarbonate is 1:

5.

3. The preparation method according to claim 1, Features: The inner diameter of the needle is 0.33-1.6 mm; the average diameter of the gel beads is 2.3-4.8 mm.

4. The preparation method according to claim 3, Features: The inner diameter of the needle is 0.33 mm; the average diameter of the gel beads is 2.3 mm.

5. The preparation method according to claim 1, Features: The ternary nano photocatalyst CuFeS 2 The preparation method is as follows: Under vacuum conditions, cuprous and ferric salts are mixed in an organic solvent to obtain solution A, and then the reaction atmosphere is switched to nitrogen, and then heating and stirring are continued; hexamethyldisilathioane is mixed with octadecene to obtain solution B, and solution B is reacted with solution A to obtain a precursor; Sodium sulfide nonahydrate is dissolved in water and an organic solvent to obtain solution C. The precursor is mixed with solution C in a cyclohexane medium to obtain CuFeS 2 Ternary nanocrystals.

6. The preparation method according to claim 5, Features: The cuprous salts include CuI, CuCl, and CuBr, and the iron salts include FeCl 3 , Fe 2 (SO 4 ) 3 The organic solvent in the solution A includes oleylamine and oleic acid.

7. The preparation method according to claim 5, Features: The concentration of hexamethyldisilathane in the solution B is 0.6-1 mol / L; the organic solvent in the solution C includes dimethylformamide, dimethylacetamide, tetrahydrofuran, acetone, and acetonitrile; The volume ratio of solution A to solution B is 1-9:1; the concentration of sodium sulfide nonahydrate in the solution C is 0.15-0.25 mol / L; the volume ratio of water to organic solvent is 1:2-4; The molar ratio of cuprous, ferric salt and hexamethyldisilathione is 1-10:1-10:20-30; the cuprous and ferric salts in solution A are 0.02-0.05 mol / L; The heating and stirring refers to reacting at 100°C to 220°C for 1 to 8 hours.

8. The preparation method according to claim 7, Features: The concentration of hexamethyldisilathione in the solution B is 0.67 mol / L; the volume ratio of solution A to solution B is 9:1; the concentration of sodium sulfide nonahydrate in the solution C is 0.2 mol / L; the volume ratio of water to organic solvent is 1:3; the molar ratio of cuprous, ferric salt and hexamethyldisilathione is 1:1:2; the cuprous and ferric salts in solution A are 0.35 mol / L.

9. A ternary nano-photocatalyst obtained by the preparation method according to any one of claims 1 to 8, used for degrading nitrobenzene in industrial wastewater.

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