A ZSAS film material for solar-driven interface evaporation and preparation method thereof

Abstract

The invention discloses a ZSAS membrane material for solar-driven interfacial evaporation and a preparation method thereof, which are applied in the technical field of functional materials. The technical scheme comprises the following key points: S1: preparing a mixed liquid: pouring γ-mercaptopropyltrimethoxysilane into deionized water under ultrasonic conditions, stirring evenly, and obtaining a mixed liquid of γ-mercaptopropyltrimethoxysilane and water for standby use; S2: preparing an emulsion: dropwise adding NH3·H2O to the mixed liquid in step S1, stirring evenly, and obtaining a white emulsion. The technical effects of the invention are as follows: the preparation process is environmentally friendly and simple, with a wide source of raw materials and low cost; the ZSAS membrane is used for solar-driven interfacial evaporation, has a fast evaporation rate, good photothermal conversion performance and mechanical properties, and also has photocatalytic performance and adsorption effects, can effectively remove pollutants in heavy metal wastewater and organic dye wastewater, can also effectively perform seawater desalination, and has a long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and in particular to a ZSAS film material for solar-driven interface evaporation and a preparation method thereof. Background Art

[0002] The use of photocatalysts to degrade organic pollutants in water is widely recognized for its high efficiency, low cost, and low energy consumption. Consequently, semiconductor-based materials with potential photocatalytic capabilities have received increasing research. Consequently, the use of semiconductor-based materials as photothermal materials in interfacial evaporation systems, in conjunction with interfacial evaporation, to degrade organic pollutants in water has garnered increasing attention.

[0003] As a layered ternary sulfide semiconductor material, ZnIn2S4 has a suitable energy band position, stable chemical properties, and is non-toxic and pollution-free. Therefore, it has great application potential in the field of environmental protection. In addition, compared with other ternary sulfides, ZnIn2S4 also has a wider range of raw material sources, which makes it relatively cost-effective. Although ZnIn2S4 has good light absorption properties under visible light, the photocatalytic efficiency of pure ZnIn2S4 is not ideal due to its high recombination rate of photogenerated electrons. In current research, it is widely believed that constructing heterostructures with ZnIn2S4 and other semiconductors can effectively reduce the tendency of photogenerated electrons and holes to recombine, thereby improving catalytic activity and stability. In addition, the bonding method between semiconductors is also worth exploring. Constructing the microstructure of the semiconductors and maximizing the contact area between the two semiconductors can maximize the transfer and separation of electrons, shorten the electron transfer distance, and further improve the catalytic performance of the composite material.

[0004] Traditional dry methods for preparing silica microspheres, such as the vapor phase method and the arc method, produce silica microsphere products with high purity and good monodispersity, but they have problems such as complex process operation, high equipment requirements, low yield, and expensive raw materials. Summary of the Invention

[0005] The present invention aims to provide a ZSAS membrane material for solar-driven interfacial evaporation and a preparation method thereof. Advantages of the present invention are: the preparation process of the present invention is environmentally friendly and simple, the raw material source is wide, and the cost is low; the ZSAS membrane is used for solar-driven interfacial evaporation, has a fast evaporation rate, good photothermal conversion performance and mechanical properties, and also has photocatalytic properties and adsorption effects, can effectively remove pollutants in heavy metal wastewater and organic dye wastewater, can also effectively desalinate seawater, and has a long service life.

[0006] A first object of the present invention is to provide a method for preparing a ZSAS film for solar-driven interfacial evaporation, comprising the following steps: S1: preparing a mixed solution: pouring γ-mercaptopropyltrimethoxysilane into deionized water under ultrasonic conditions and stirring uniformly to obtain a mixed solution of γ-mercaptopropyltrimethoxysilane and water for later use;

[0007] S2: preparing an emulsion: adding NH3·H2O dropwise to the mixed solution in step S1 and stirring to obtain a white emulsion;

[0008] S3: producing organosilicon microspheres: centrifuging, washing and freeze-drying the emulsion in step S2 to obtain organosilicon microspheres;

[0009] S4: Under ultrasonic conditions, ethylene glycol is added to deionized water and ultrasonically dispersed for 5-20 minutes. ZnCl2, InCl3·4H2O, organosilicon microspheres, and sodium citrate are then dissolved in the solution. After stirring, thioacetamide is added and stirring is continued to obtain a mixture.

[0010] S5: The mixture obtained in step S4 is transferred to a reactor and reacted at 110°-130°C. After the reaction is completed, the mixture is centrifuged and rinsed three times with deionized water and ethanol, and freeze-dried to obtain a ZnIn2S4@SiO2 composite material;

[0011] S6: Disperse the ground activated carbon powder in HNO3 solution, stir for 8-14 hours, rinse with deionized water, and dry for later use;

[0012] S7: Under ultrasonic conditions, the activated carbon powder in step S6 is dispersed in deionized water, and sodium alginate is added to the above solution and mixed with stirring to prepare a black hydrogel;

[0013] S8: The black hydrogel in step S7 is frozen and dried to obtain a black SA aerogel;

[0014] S9: The ZnIn2S4@SiO2 composite material in step S5 is dispersed in a CaCl2 solution, and black SA aerogel is added for cross-linking. After the reaction is completed, the mixture is immersed in deionized water, and finally freeze-dried to obtain a ZSAS membrane.

[0015] The present invention is further configured as follows: in step S1, the amount of γ-mercaptopropyltrimethoxysilane is 0.8-1.5 g, and the stirring time is 1-1.5 h.

[0016] The present invention is further configured as follows: in step S4, the mass percentage of the NH3·H2O is 26-30 wt%.

[0017] The present invention is further configured as follows: the amount of the organosilicon microspheres is 0.05-0.2 g, the stirring time is 20-50 min, and the amount of the thioacetamide is 0.1-0.2 g.

[0018] The present invention is further configured as follows: in step S5, the ZnIn2S4@SiO2 composite material is specifically ZS-1, ZS-2, ZS-3 and ZS-4.

[0019] The present invention is further configured as follows: in step S6, the concentration of the HNO3 solution is 1.8-2.2 mol / L, and the volume of the HNO3 solution is 10-20 mL.

[0020] The present invention is further configured as follows: in step S6, the drying temperature is 50-70°C and the drying time is 10-14 hours.

[0021] The present invention is further configured as follows: in step S7, the amount of sodium alginate added is 0.8-1.2 g.

[0022] The present invention is further configured as follows: in step S9, the mass percentage of the CaCl2 solution is 1.8-2.2wt%, and the capacity of the CaCl2 solution is 8-12mL.

[0023] The second object of the present invention is to provide a ZSAS membrane material prepared by the aforementioned method.

[0024] In summary

[0025] 1. In the present invention, for the first time, in a weak alkaline environment created by ammonia water, γ-mercaptopropyltrimethoxysilane is hydrolyzed to produce organosilicon microspheres (OSMS) with mercapto groups on the surface; zinc chloride, indium chloride and sodium citrate are dissolved in a mixed solution of ethylene glycol and ultrapure water to create a weak alkaline environment, and then OSMS and thioacetamide (TAA) are dispersed and dissolved in the above solution. 2+ and In 3+ The S 2- ZnIn2S4 was self-assembled in situ on the OSMS surface and freeze-dried to obtain a ZnIn2S4@SiO2 composite material. The ZnIn2S4@SiO2 composite material was dispersed in a CaCl2 solution and loaded onto the aerogel surface using a cross-linking chemical reaction of sodium alginate aerogel. The ZSAS interfacial evaporation film was then freeze-dried.

[0026] 2. The preparation process of the present invention is environmentally friendly, simple, has a wide source of raw materials, and is low in cost. The ZSAS membrane is used for solar-driven interfacial evaporation, has a fast evaporation rate, good photothermal conversion performance and mechanical properties, and also has photocatalytic properties and adsorption effects. It can effectively remove pollutants in heavy metal wastewater and organic dye wastewater, and can also effectively desalinate seawater with a long service life.

[0027] 3. The ZSAS membrane prepared by the present invention is used for solar-driven interfacial water evaporation, has a fast evaporation rate, and has good photothermal conversion performance and mechanical properties.

[0028] 4. The ZSAS membrane prepared by the present invention can effectively remove the main ions in seawater and has a long service life. It can also adapt well to salt water environments with various salt concentrations.

[0029] 5. The ZSAS membrane prepared by the present invention has good photocatalytic performance and adsorption effect, and can effectively remove pollutants in heavy metal wastewater and organic dye wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 (a) is a macroscopic structural image of the ZSAS membrane of Example 1 of the present invention; (b) is a picture of the petals of Example 1 of the present invention; (cf) are SEM images of the ZSAS membrane of Example 1 of the present invention; (g) is a picture of the ZSAS membrane of Example 1 of the present invention before ultrasonic treatment; (h) is a picture of the ZSAS membrane of Example 1 of the present invention after 20 minutes of ultrasonic treatment;

[0031] Figure 2 (a) is the overall dispersion SEM image of OSMS in Example 1 of the present invention; (b) is the overall dispersion SEM image of ZnIn2S4@SiO2 in Example 1 of the present invention; (c) is the particle size distribution of OSMS in Example 1 of the present invention; (d) is the particle size distribution of ZnIn2S4@SiO2 in Example 1 of the present invention;

[0032] Figure 3 (a) is an SEM image of the OSMS of Example 1 of the present invention; (b) is an SEM image of the ZnIn2S4@SiO2 composite material of Example 1 of the present invention; (c) is a TEM image of the ZnIn2S4@SiO2 composite material of Example 1 of the present invention; (d) is a sheet structure of ZnIn2S4 attached to the surface of Example 1 of the present invention; (e) is an HRTEM image of ZnIn2S4 on the surface of OSMS of Example 1 of the present invention; (fi) is an EDS element distribution diagram of ZnIn2S4@SiO2 of (f) silicon, (g) zinc, (h) indium and (i) sulfur in Example 1 of the present invention;

[0033] Figure 4(a) is the Fourier transform infrared spectrum of OSMS and ZnIn2S4@SiO2 in Example 1 of the present invention; (b) is the XRD pattern of pure OSMS and ZnIn2S4 and ZnIn2S4@SiO2 composite materials with different organosilicon contents in Example 1 of the present invention; (cf) are high-resolution XPS spectra of (c) zinc, (d) indium, (e) silicon and (f) sulfur elements in the composite material of Example 1 of the present invention;

[0034] Figure 5 (a) Absorbance test of various interface evaporation films in the full spectrum range of Example 1 of the present invention and the test example; (b) The maximum temperature reached on the surface of pure water and various interface evaporation films in Example 1 of the present invention and the test example after irradiation at one solar intensity for 1 hour; (c) The mass change of pure water and water with evaporation film in Example 1 of the present invention and the test example after irradiation at one solar intensity for 1 hour; (d) The evaporation rate and photothermal conversion efficiency of pure water and various sample films in Example 1 of the present invention and the test example; (e) Performance comparison of ZSAS-3 membrane in Example 1 of the present invention and the test example with other reported aerogel evaporators; (f) The mass change of water treated by ZSAS-3 membrane in dark environment and different light intensities in Example 1 of the present invention and the test example;

[0035] Figure 6 (a) is the compressive stress-strain curve of ZSAS-3 in Example 1 and the test example of the present invention; (b) is the compressive stress-strain curve of SA in Example 1 and the test example of the present invention; (c) is the compressive stress-strain curve of the uncross-linked pure sodium alginate aerogel in Example 1 and the test example of the present invention;

[0036] Figure 7 (a) is the resistivity test of the seawater distillate of Example 1 and the test example of the present invention; (b) is the resistivity test of tap water of Example 1 and the test example of the present invention; (c) is the resistivity test of the simulated seawater of Example 1 and the test example of the present invention;

[0037] Figure 8 (a) is the ion removal rate of ZSAS-3 in simulated seawater according to Example 1 and the test example of the present invention; (b) is the continuous seawater desalination capacity evaluation of ZSAS-3 according to Example 1 and the test example of the present invention; (c) is the mass change of salt water of different concentrations under the action of ZSAS-3 according to Example 1 and the test example of the present invention; (d) is the evaporation rate of ZSAS-3 in salt water of different concentrations according to Example 1 and the test example of the present invention;

[0038] Figure 9(a) is the removal rate of heavy metal ions by ZSAS-3 in Example 1 of the present invention and the experimental example; (b) is the removal rate of organic dyes by different interface evaporated films in Example 1 of the present invention and the experimental example; (c) is the impedance curve of pure ZnIn2S4 and ZnIn2S4@SiO2 composite materials in Example 1 of the present invention and the experimental example; (d) is the photocurrent curve of pure ZnIn2S4 and ZnIn2S4@SiO2 composite materials in Example 1 of the present invention and the experimental example. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Example 1:

[0041] A method for preparing a ZSAS film for solar-driven interfacial evaporation, comprising:

[0042] (1) The preparation method of organosilicon microspheres (OSMS) includes:

[0043] Under ultrasonic conditions, 1 g of γ-mercaptopropyltrimethoxysilane (TMST) was slowly added dropwise to a three-necked flask containing 250 mL of deionized water, and then stirred for 1 hour until the TMST and water were evenly mixed. 3.5 mL of NH3·H2O (28 wt%) was then slowly added dropwise to the mixture, and stirred for 12 hours using a mechanical stirrer until the mixture became a white emulsion. The mixture was then centrifuged at graded speeds, washed, and freeze-dried to obtain organosilicon microspheres.

[0044] (2) The preparation method of the ZnIn2S4@SiO2 composite material (ZS) includes:

[0045] Under ultrasonic conditions, 10 mL of ethylene glycol (EG) was added to 20 mL of deionized water and ultrasonically dispersed for 20 minutes to dissolve ZnCl2, InCl3·4H2O and sodium citrate in the above solution. Then, a certain amount of 0.05 g of OSMS was dispersed into the solution, stirred thoroughly for 30 minutes, and 150 mg of thioacetamide (TAA) was dissolved in the solution and stirred for another 30 minutes. The mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted at 120 ° C for 12 hours. After the reaction, the mixture was centrifuged and rinsed three times with deionized water and ethanol and freeze-dried to obtain ZnIn2S4@SiO2 composite materials, which were respectively ZS-1 and set aside;

[0046] (3) The preparation method of ZnIn2S4@SiO2 / AC@SA (ZSAS) evaporated film includes:

[0047] Ground activated carbon (AC) powder was dispersed in 15 mL of 2 mol / L HNO₃ solution and stirred continuously for 12 hours to remove surface ash. The treated AC was centrifuged and rinsed with deionized water to remove residual HNO₃ solution, then dried at 60°C for 12 hours before use. The resulting AC powder was dispersed in 25 mL of deionized water under ultrasonic conditions. 1 g of sodium alginate (SA) was then added to the mixture and stirred vigorously to produce a black hydrogel. ZS-1 was dispersed in 10 mL of 2 wt% CaCl₂ solution. The freeze-dried black SA aerogel was then immersed in this mixture for crosslinking. The ZnIn₂S₄@SiO₂ composite was then loaded onto the surface of the black SA aerogel via chemical crosslinking. The crosslinked black aerogel was then immersed in deionized water for 12 hours to remove excess CaCl₂. The ZSAS membrane, designated ZSAS-1, was obtained after freeze-drying to obtain the ZSAS membrane.

[0048] Example 2:

[0049] A method for preparing a ZSAS film for solar-driven interfacial evaporation, comprising:

[0050] (1) The preparation method of organosilicon microspheres (OSMS) includes:

[0051] Under ultrasonic conditions, 1 g of γ-mercaptopropyltrimethoxysilane (TMST) was slowly added dropwise to a three-necked flask containing 250 mL of deionized water, and then stirred for 1 hour until the TMST and water were evenly mixed. 3.5 mL of NH3·H2O (28 wt%) was then slowly added dropwise to the mixture, and stirred for 12 hours using a mechanical stirrer until the mixture became a white emulsion. The mixture was then centrifuged at graded speeds, washed, and freeze-dried to obtain organosilicon microspheres.

[0052] (2) The preparation method of the ZnIn2S4@SiO2 composite material (ZS) includes:

[0053] Under ultrasonic conditions, 10 mL of ethylene glycol (EG) was added to 20 mL of deionized water and ultrasonically dispersed for 20 minutes to dissolve ZnCl2, InCl3·4H2O, and sodium citrate in the above solution. Then, a certain amount of 0.1 g of OSMS was dispersed into the solution, stirred thoroughly for 30 minutes, and 150 mg of thioacetamide (TAA) was dissolved in the solution and stirred for another 30 minutes. The mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted at 120 ° C for 12 hours. After the reaction, the mixture was centrifuged and rinsed three times with deionized water and ethanol and freeze-dried to obtain a ZnIn2S4@SiO2 composite material, which was named ZS-2 and set aside.

[0054] (3) The preparation method of ZnIn2S4@SiO2 / AC@SA (ZSAS) evaporated film includes:

[0055] Ground activated carbon (AC) powder was dispersed in 15 mL of 2 mol / L HNO₃ solution and stirred continuously for 12 hours to remove surface ash. The treated AC was centrifuged and rinsed with deionized water to remove residual HNO₃ solution, then dried at 60°C for 12 hours before use. The resulting AC powder was dispersed in 25 mL of deionized water under ultrasonic conditions. 1 g of sodium alginate (SA) was then added to the mixture and stirred vigorously to produce a black hydrogel. ZS-1, ZS-2, ZS-3, and ZS-4 were each dispersed in 10 mL of 2 wt% CaCl₂ solution. The freeze-dried black SA aerogels were then immersed in this mixture for crosslinking. The ZnIn₂S₄@SiO₂ composite was then loaded onto the surface of the black SA aerogels via chemical crosslinking. The crosslinked black aerogels were then immersed in deionized water for 12 hours to remove excess CaCl₂. The ZSAS membrane, designated ZSAS-2, was then freeze-dried.

[0056] Example 3:

[0057] A method for preparing a ZSAS film for solar-driven interfacial evaporation, comprising:

[0058] (1) The preparation method of organosilicon microspheres (OSMS) includes:

[0059] Under ultrasonic conditions, 1 g of γ-mercaptopropyltrimethoxysilane (TMST) was slowly added dropwise to a three-necked flask containing 250 mL of deionized water, and then stirred for 1 hour until the TMST and water were evenly mixed. 3.5 mL of NH3·H2O (28 wt%) was then slowly added dropwise to the mixture, and stirred for 12 hours using a mechanical stirrer until the mixture became a white emulsion. The mixture was then centrifuged at graded speeds, washed, and freeze-dried to obtain organosilicon microspheres.

[0060] (2) The preparation method of the ZnIn2S4@SiO2 composite material (ZS) includes:

[0061] Under ultrasonic conditions, 10 mL of ethylene glycol (EG) was added to 20 mL of deionized water and ultrasonically dispersed for 20 minutes to dissolve ZnCl2, InCl3·4H2O and sodium citrate in the above solution. Then, a certain amount of 0.15 g of OSMS was dispersed into the solution, stirred thoroughly for 30 minutes, and 150 mg of thioacetamide (TAA) was dissolved in the solution and stirred for another 30 minutes. The mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted at 120 ° C for 12 hours. After the reaction, the mixture was centrifuged and rinsed three times with deionized water and ethanol and freeze-dried to obtain a ZnIn2S4@SiO2 composite material, which was named ZS-3 and set aside.

[0062] (3) The preparation method of ZnIn2S4@SiO2 / AC@SA (ZSAS) evaporated film includes:

[0063] Ground activated carbon (AC) powder was dispersed in 15 mL of 2 mol / L HNO₃ solution and stirred continuously for 12 hours to remove surface ash. The treated AC was centrifuged and rinsed with deionized water to remove residual HNO₃ solution, then dried at 60°C for 12 hours before use. The resulting AC powder was dispersed in 25 mL of deionized water under ultrasonic conditions. 1 g of sodium alginate (SA) was then added to the mixture and stirred vigorously to produce a black hydrogel. ZS-1, ZS-2, ZS-3, and ZS-4 were each dispersed in 10 mL of 2 wt% CaCl₂ solution. The freeze-dried black SA aerogels were then immersed in this mixture for crosslinking. The ZnIn₂S₄@SiO₂ composite was then loaded onto the surface of the black SA aerogels via chemical crosslinking. The crosslinked black aerogels were then immersed in deionized water for 12 hours to remove excess CaCl₂. The ZSAS membrane, designated ZSAS-3, was then freeze-dried to obtain the ZSAS membrane.

[0064] Figure 1 (a) is a macroscopic structural image of the ZSAS membrane of Example 3 of the present invention; it can be seen from the figure that the ZSAS membrane is brown-black in color as a whole;

[0065] Figure 1 (b) is a picture of Example 3 of the present invention on a petal. From the picture, it can be seen that the ZSAS membrane is easily supported by the petal, indicating that the overall mass of the ZSAS membrane is very light;

[0066] Figure 1 (cf) is the SEM image of the ZSAS membrane of Example 3 of the present invention, Figure 1 As can be seen from Figures c and d, the upper surface of the ZSAS membrane has a large number of irregular pore structures. These pore structures greatly increase the specific surface area of the ZSAS membrane, which is beneficial to the adhesion of the composite material in the later stage. Figure 1As shown in Figures e and f, the freeze-dried ZSAS membrane exhibits a relatively uniform vertical array structure, which provides abundant channels for the transport of water during evaporation.

[0067] Figure 1 (g) is a ZSAS membrane image before ultrasonic treatment in Example 3 of the present invention, Figure 1 (h) is a picture of the ZSAS membrane after 20 minutes of ultrasonic treatment in Example 3 of the present invention. It can be seen from the figure that after 20 minutes of ultrasonic treatment, the ZnIn2S4@SiO2 on the surface did not show obvious shedding, which greatly reduced the performance degradation and cost loss caused by material shedding during the working process.

[0068] Figure 2 (a) is a SEM image of the overall dispersion of OSMS in Example 3 of the present invention. It can be seen from the figure that silica microspheres with good monodispersity are obtained;

[0069] Figure 2 (b) is the overall dispersion SEM image of ZnIn2S4@SiO2 of Example 3 of the present invention. It can be seen from the figure that the synthesized ZnIn2S4@SiO2 also has relatively good dispersibility;

[0070] Figure 2 (c) is the OSMS particle size distribution diagram of Example 3 of the present invention, from Figure 2 It can be seen from Figures b and c that the particle size of ZnIn2S4@SiO2 is slightly larger than that of silica microspheres.

[0071] Figure 2 (d) is the particle size distribution diagram of ZnIn2S4@SiO2 in Example 3 of the present invention.

[0072] Figure 3 (a) is a SEM image of the OSMS of Example 3 of the present invention. It can be seen from the figure that the pure OSMS has a relatively smooth surface;

[0073] Figure 3 (b) is an SEM image of the ZnIn2S4@SiO2 composite material of Example 3 of the present invention. It can be seen from the figure that the surface of ZnIn2S4@SiO2 is obviously rougher due to the presence of ZnIn2S4;

[0074] Figure 3 (c) is a TEM image of the ZnIn2S4@SiO2 composite material of Example 3 of the present invention. It can be seen from the figure that the coverage thickness of each part is inconsistent;

[0075] Figure 3(d) is the sheet structure of ZnIn2S4 attached to the surface of OSMS of Example 3 of the present invention. As can be seen from the figure, the loaded ZnIn2S4 presents a very thin sheet structure, which can effectively increase the specific surface area of the composite material and is more conducive to the photodegradation of organic pollutants in later applications;

[0076] Figure 3 (e) is the HRTEM image of ZnIn2S4 on the OSMS surface of Example 3 of the present invention. As can be seen from the figure, the HRTEM image of ZnIn2S4 shows obvious lattice fringes with a lattice spacing of 0.325 nm, which corresponds to the (102) crystal plane of ZnIn2S4;

[0077] Figure 3 (fi) is the EDS element distribution diagram of (f) silicon, (g) zinc, (h) indium and (i) sulfur in ZnIn2S4@SiO2 of Example 3 of the present invention. It can be seen from the figure that the distribution ranges of elements such as Zn, In, S correspond to the distribution area of ZnIn2S4, and can evenly cover the distribution range of Si element, which once again proves the successful synthesis of ZnIn2S4 on OSMS and its high coverage.

[0078] Figure 4 (a) is the Fourier transform infrared spectrum of OSMS and ZnIn2S4@SiO2 of Example 3 of the present invention. As can be seen from the figure, (b) is the XRD spectrum of pure OSMS and ZnIn2S4 of Example 1 of the present invention and the ZnIn2S4@SiO2 composite material with different organic silicon contents. As can be seen from the figure, (cf) is the high-resolution XPS spectrum of (c) zinc, (d) indium, (e) silicon and (f) sulfur elements in the ZnIn2S4@SiO2 composite material of Example 3 of the present invention. As can be seen from the figure, the above series of test results all prove the successful construction of the ZnIn2S4@SiO2 composite material.

[0079] Example 4:

[0080] A method for preparing a ZSAS film for solar-driven interfacial evaporation, comprising:

[0081] (1) The preparation method of organosilicon microspheres (OSMS) includes:

[0082] Under ultrasonic conditions, 1 g of γ-mercaptopropyltrimethoxysilane (TMST) was slowly added dropwise to a three-necked flask containing 250 mL of deionized water, and then stirred for 1 hour until the TMST and water were evenly mixed. 3.5 mL of NH3·H2O (28 wt%) was then slowly added dropwise to the mixture, and stirred for 12 hours using a mechanical stirrer until the mixture became a white emulsion. The mixture was then centrifuged at graded speeds, washed, and freeze-dried to obtain organosilicon microspheres.

[0083] (2) The preparation method of the ZnIn2S4@SiO2 composite material (ZS) includes:

[0084] Under ultrasonic conditions, 10 mL of ethylene glycol (EG) was added to 20 mL of deionized water and ultrasonically dispersed for 20 minutes to dissolve ZnCl2, InCl3·4H2O and sodium citrate in the above solution. Then, a certain amount of 0.2 g of OSMS was dispersed into the solution, stirred thoroughly for 30 minutes, and 150 mg of thioacetamide (TAA) was dissolved in the solution and stirred for another 30 minutes. The mixture was transferred to a polytetrafluoroethylene-lined reactor and reacted at 120 ° C for 12 hours. After the reaction, the mixture was centrifuged and rinsed three times with deionized water and ethanol and freeze-dried to obtain a ZnIn2S4@SiO2 composite material, which was named ZS-4 and set aside.

[0085] (3) The preparation method of ZnIn2S4@SiO2 / AC@SA (ZSAS) evaporated film includes:

[0086] Ground activated carbon (AC) powder was dispersed in 15 mL of 2 mol / L HNO₃ solution and stirred continuously for 12 hours to remove surface ash. The treated AC was centrifuged and rinsed with deionized water to remove residual HNO₃ solution, then dried at 60°C for 12 hours before use. The resulting AC powder was dispersed in 25 mL of deionized water under ultrasonic conditions. Then, 1 g of sodium alginate (SA) was added to the mixture and stirred vigorously to produce a black hydrogel. ZS-1, ZS-2, ZS-3, and ZS-4 were dispersed in 10 mL of 2 wt% CaCl₂ solution. The freeze-dried black SA aerogels were then immersed in this mixture for crosslinking. The ZnIn₂S₄@SiO₂ composite was then loaded onto the surface of the black SA aerogels via chemical crosslinking. The crosslinked black aerogels were immersed in deionized water for 12 hours to remove excess CaCl₂ and freeze-dried to produce a ZSAS membrane, designated ZSAS-4.

[0087] Test example:

[0088] 1. Solar-driven interfacial water evaporation experiment

[0089] (1) Test method:

[0090] Under indoor conditions of a temperature of 28-30°C and a humidity of 37-39%, a xenon lamp was used as the light source. An AM1.5G filter was used to control the wavelength to the solar wavelength. Simulating sunlight, solar-driven interfacial water evaporation was performed. A suitable amount of pure water was poured into a quartz beaker. The ZSAS membranes of Examples 1-4 were embedded in polyethylene foam and floated on the water surface of the beaker. The quartz beaker was then placed on an electronic balance to monitor the changes in water quality in real time. The test results are shown in FIG. Figure 5 shown.

[0091] (2) Test results and conclusions:

[0092] from Figure 5 As can be seen from a, the absorbance of the ZSAS films prepared in Examples 1-4 of the present invention can reach more than 80% in the full spectrum range; Figure 5 As can be seen from Figures 5b and 5c, after one hour of irradiation at one solar intensity, the surface temperature of the ZSAS-3 membrane prepared in Example 3 of the present invention is the highest, and the quality of evaporated water is the highest; Figure 5 As shown in Figure d, the evaporation rate of the ZSAS films prepared in Examples 1-4 can reach 1.4 kg / m -2 h -1 Among them, ZSAS-3 has the fastest evaporation rate and the highest photothermal efficiency, with an evaporation rate of 1.485 kg / m -2 h -1 , the photothermal efficiency reaches 96.33%; Figure 5 As shown in Figure 5, the excellent evaporation rate and good photothermal efficiency of the ZSAS-3 film are also very competitive among the reported aerogel-based interface evaporators; Figure 5 As shown in Figure f, under 0.6 solar intensity, the evaporation rate of the ZSAS-3 film can still reach 1.263 kg / m -2 h -1 , which is about 8 times the evaporation rate in the dark state. The evaporation rate under 3 suns of light even reached an astonishing 3.507 kg / m -2 h -1 ,In summary, the ZSAS-3 membrane has excellent evaporation performance and photothermal conversion performance.

[0093] 2. Mechanical properties experiment of interface evaporation film

[0094] (1) Test method:

[0095] Cyclic compression tests were performed on uncrosslinked sodium alginate aerogel, crosslinked sodium alginate aerogel (SA), and ZSAS-3. The compression deformation was set to 50%, and each sample was cyclically compressed 30 times. The compressive stress-strain curves of the samples were plotted. The test results are shown in Figure 2. Figure 6shown.

[0096] (2) Test results and conclusions:

[0097] from Figure 6 It can be seen that the maximum compressive stress of ZSAS-3 in the first compression cycle and the fifth compression cycle is higher than that of SA and uncross-linked sodium alginate aerogel. It can be seen that the cross-linked ZSAS-3 doped with activated carbon powder has better mechanical stability.

[0098] 3. Solar-driven seawater desalination and sewage treatment experiments

[0099] (1) Test method:

[0100] Under indoor conditions of a temperature of 28-30°C and a humidity of 37-39%, a xenon lamp was used as the light source, and an AM1.5G filter was used to control the wavelength to the solar wavelength. Solar-driven interfacial water evaporation was performed under simulated sunlight. An appropriate amount of simulated seawater or simulated sewage was poured into a quartz beaker, which was placed in a closed transparent quartz collector. The ZSAS-3 membrane of Example 3 was embedded in polyethylene foam and floated on the water surface of the beaker. The concentration of the distillate of the simulated seawater or simulated heavy metal sewage in the collector was measured by a resistivity meter and an inductively coupled plasma mass spectrometer (ICP). The concentration of the distillate of the simulated organic dye sewage in the collector was measured by ultraviolet spectroscopy and high-performance liquid chromatography. The test results are shown in FIG. Figure 7 、 Figure 8 and Figure 9 shown.

[0101] (2) Test results and conclusions:

[0102] from Figure 7 and Figure 8 As can be seen in a, the concentrations of sodium ions, potassium ions, calcium ions, magnesium ions, and boron ions in the seawater distillate treated with the ZSAS-3 membrane have all decreased significantly compared to the original solution, and are far below the minimum standard for ion concentration in desalinated seawater stipulated by the World Health Organization. The ion removal rate can reach about 99.9%; Figure 8 As shown in Figure 2, the desalination capacity of ZSAS-3 in simulated seawater was tested in a cyclic test. The cyclic experiment included five cycles, each lasting 8 hours. The evaporation rate in each cycle was maintained at 1.33 kg / m -2 h -1 There is no significant decrease in evaporation rate due to continuous operation, indicating that the ZSAS-3 membrane has excellent and stable seawater desalination function and a long working life. Figure 8 c and Figure 8d shows the evaporation performance of ZSAS-3 in brine with different salt concentrations. It can be seen that the surface ZSAS-3 membrane can maintain a relatively good desalination capacity in brine with a salt concentration of at least 7.0 wt%. Figure 9 As can be seen in Figure a, after the three heavy metal wastewaters containing cadmium ions, chromium ions and lead ions were treated with the ZSAS-3 membrane, the corresponding heavy metal ion content in their distillates was significantly reduced, and the removal rate of the three heavy metal ions was able to reach more than 99.9%, which has met the standards for heavy metal ion content in drinking water stipulated by the World Health Organization. Figure 9 As can be seen in b, after the three organic dye wastewaters containing methyl orange, rhodamine B and methylene blue were treated by ZSAS-3 membrane, the organic dye removal rate in their distillates was the highest, indicating that ZSAS-3 membrane has excellent purification function for heavy metal wastewater and organic dye wastewater. Figure 9 As shown in Figure b, in order to detect the photodegradation and adsorption effects of ZnIn2S4@SiO2 on organic pollutants, SA (cross-linked sodium alginate aerogel) and AC / SA (cross-linked sodium alginate aerogel doped with activated carbon powder) were also selected as control groups. It was found that the heterogeneous structure formed between ZnIn2S4 and SiO2 promoted the transfer of photogenerated electrons and improved the photocatalytic performance of ZSAS-3. In addition, the purification function of ZSAS-3 and AC / SA doped with activated carbon was better than that of SA because of the adsorption effect of activated carbon.

[0103] 4. ZnIn2S4@SiO2 photoelectric performance experiment

[0104] (1) Test method:

[0105] A small amount of ZnIn2S4@SiO2 composite material was dispersed in ethanol solution, coated on conductive glass and dried for use. 0.2M sodium sulfate solution was used as the electrolyte solution, Ag / AgCl and Pt electrodes were used as the reference electrode and counter electrode, respectively. The impedance and photocurrent curves of ZnIn2S4@SiO2 composite material and ZnIn2S4 under light conditions were tested respectively.

[0106] (2) Test results and conclusions:

[0107] from Figure 9 c and Figure 9 As can be seen in Figure d, the heterostructure formed between ZnIn2S4 and SiO2 does indeed reduce the impedance of pure ZnIn2S4 and increase the lifetime of photogenerated electrons. This also proves that the selected semiconductor-based composite photothermal material has excellent photothermal performance while achieving photodegradation of organic dye pollutants in water.

[0108] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing a ZSAS film for solar-driven interfacial evaporation, characterized in that: The steps include: S1: preparing a mixed solution: pouring γ-mercaptopropyltrimethoxysilane into deionized water under ultrasonication and stirring evenly to obtain a mixed solution of γ-mercaptopropyltrimethoxysilane and water for later use; S2: preparing an emulsion: adding NH3·H2O dropwise to the mixed solution in step S1 and stirring to obtain a white emulsion; S3: producing organosilicon microspheres: centrifuging, washing and freeze-drying the emulsion in step S2 to obtain organosilicon microspheres; S4: Under ultrasonic conditions, ethylene glycol is added to deionized water and ultrasonically dispersed for 5-20 minutes. ZnCl2, InCl3·4H2O, organosilicon microspheres, and sodium citrate are then dissolved in the solution. After stirring, thioacetamide is added and stirring is continued to obtain a mixture. S5: The mixture obtained in step S4 is transferred to a reactor and reacted at 110°-130°C. After the reaction is completed, the mixture is centrifuged and rinsed three times with deionized water and ethanol, and freeze-dried to obtain a ZnIn2S4@SiO2 composite material; S6: Disperse the ground activated carbon powder in HNO3 solution, stir for 8-14 hours, rinse with deionized water, and dry for later use; S7: Under ultrasonic conditions, the activated carbon powder in step S6 is dispersed in deionized water, and sodium alginate is added to the above solution and mixed with stirring to prepare a black hydrogel; S8: The black hydrogel in step S7 is frozen and dried to obtain a black SA aerogel; S9: The ZnIn2S4@SiO2 composite material in step S5 is dispersed in a CaCl2 solution, and black SA aerogel is added for cross-linking. After the reaction is completed, the mixture is immersed in deionized water, and finally freeze-dried to obtain a ZSAS membrane.

2. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S1, the amount of γ-mercaptopropyltrimethoxysilane is 0.8-1.5 g, and the stirring time is 1-1.5 h.

3. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S2, the mass percentage of NH3·H2O is 26-30 wt%.

4. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S4, the amount of the organosilicon microspheres is 0.05-0.2 g, the stirring time is 20-50 min, and the amount of the thioacetamide is 0.1-0.2 g.

5. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S5, the ZnIn2S4@SiO2 composite material is specifically ZS-1 or ZS-2 or ZS-3 or ZS-4.

6. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S6, the concentration of the HNO3 solution is 1.8-2.2 mol / L, and the amount of the HNO3 solution used is 10-20 mL.

7. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S6, the drying temperature is 50-70° C. and the drying time is 10-14 hours.

8. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S7, the amount of sodium alginate added is 0.8-1.2 g.

9. The method for preparing a ZSAS film for solar-driven interfacial evaporation according to claim 1, characterized in that: In step S9, the mass percentage of the CaCl2 solution is 1.8-2.2 wt%, and the amount of the CaCl2 solution used is 8-12 mL.

10. A ZSAS membrane material prepared according to the method according to any one of claims 1 to 9.

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