ZIS / NaCOF-2 catalyst, preparation method thereof and application of ZIS / NaCOF-2 catalyst in photocatalytic production of H2O2

Abstract

The invention relates to the technical field of catalyst preparation, in particular to a ZIS / NaCOF-2 catalyst, a preparation method of the ZIS / NaCOF-2 catalyst and application of the ZIS / NaCOF-2 catalyst in photocatalytic production of H2O2, NaOH is dissolved in a mixed solvent of ethyl alcohol and water, then 1, 4-diacetylbenzene is added to obtain a mixed solution, ammonia water and 2, 5-dimethoxybenzene-1, 4-dicarboxaldehyde are added into the mixed solution, stirring is conducted at the room temperature, and NaCOF-2 is obtained; znIn2S4 quantum dots and NaCOF-2 are ground, mixed and dried in absolute ethyl alcohol to obtain the ZIS / NaCOF-2 catalyst, the structure of the catalyst is optimized, the absorption efficiency of the catalyst to sunlight is improved, the recombination rate of photon-generated carriers is reduced, the selectivity of the catalyst to H2O2 is enhanced, and the composition, the structure and the morphology of the catalyst are accurately regulated and controlled, so that the more efficient photocatalytic H2O2 production process is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and specifically relates to a ZIS / NaCOF-2 catalyst, a preparation method thereof, and an application thereof in photocatalytic production of H2O2. Background Art

[0002] As a high-value multifunctional chemical, H2O2 exhibits extensive application potential in multiple fields such as chemical synthesis, medical disinfection, and wastewater treatment. With the enhancement of environmental protection awareness and the increasing demand for sustainable development, the demand for H2O2 is expected to continue to grow. The traditional anthraquinone method for preparing H2O2 has disadvantages such as high energy consumption, intensive waste, and toxic by-products, which do not conform to the development trend of green chemistry. Therefore, photocatalytic production of H2O2, as a green, sustainable, and energy-saving production method, has attracted extensive attention in recent years. This method uses abundant solar energy and renewable H2O and O2 as raw materials to synthesize H2O2 through photocatalytic oxygen reduction reaction (ORR, 2e - ), and has advantages such as mild reaction conditions, simple and controllable operation, and no secondary pollution. However, the efficiency of photocatalytic production of H2O2 is still limited by factors such as the small absorption range of sunlight by photocatalysts, easy recombination of photogenerated carriers, many side reactions, and poor selectivity of H2O2.

[0003] Currently, photocatalysts mainly include various oxide and sulfide semiconductors such as titanium dioxide, zinc oxide, tin oxide, zirconium dioxide, and cadmium sulfide. The preparation methods mainly include sol-gel method, impregnation method, and co-precipitation method, etc. However, the existing preparation methods have problems such as complex preparation processes, high requirements for condition control, low light source utilization rate, and easy recombination of photogenerated electron-hole pairs, resulting in low photoquantum efficiency. Summary of the Invention

[0004] Aiming at the above deficiencies of the prior art, the purpose of the present invention is to provide a ZIS / NaCOF-2 catalyst, a preparation method thereof, and an application thereof in photocatalytic production of H2O2. By optimizing the catalyst structure, the present invention improves its absorption efficiency of sunlight, reduces the recombination rate of photogenerated carriers, and enhances the selectivity of H2O2. By precisely regulating the ZIS / NaCOF-2 with different mass ratios, structure, and morphology, a more efficient photocatalytic production of H2O2 process can be achieved.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: Dissolve NaOH in a mixed solvent of ethanol and water, then add 1,4-diacetylbenzene to obtain a mixed solution. Next, add ammonia water and 2,5-dimethoxybenzene-1,4-dicarbaldehyde to the mixed solution and stir at room temperature. NaCOF-2 is obtained through the Diels-Alder reaction. This method is simple in operation, constructs a D-A type COF, and after 20 synthesis cycles, its morphological structure still shows good stability.

[0006] Prepare ZnIn2S4 quantum dots. Grind and mix ZnIn2S4 quantum dots and NaCOF-2 in anhydrous ethanol, and obtain the ZIS / NaCOF-2 catalyst after drying.

[0007] The reason why the ZIS / NaCOF-2 catalyst prepared in the present invention has high efficiency for photocatalytic production of H2O2 is mainly that it forms an S-type heterojunction. This special structure promotes the effective separation of photogenerated electrons and holes, reduces the recombination of electron-hole pairs, and thus increases the number of electrons participating in the reduction reaction to generate H2O2. Specifically, the S-type heterojunction is composed of two semiconductors with staggered energy bands, and a built-in electric field is formed at the interface. This electric field accelerates the separation and transport of carriers, enabling more photogenerated electrons to participate in the reaction for generating H2O2. Therefore, the ZIS / NaCOF-2 catalyst significantly improves the efficiency of photocatalytic production of H2O2 by forming an S-type heterojunction. Moreover, the preparation method of the present invention is simple, the reaction conditions are mild, and by optimizing the structure of the catalyst, the absorption efficiency of sunlight is improved, the recombination rate of photogenerated carriers is reduced, and the selectivity for H2O2 is enhanced.

[0008] The structural formula of NaCOF-2 (4-(2,5-dimethoxyphenyl isocyanate)-2,6-diphenylpyridine) is as follows: 。

[0009] In a preferred embodiment of the present invention, in the ZIS / NaCOF-2 catalyst, the mass percentage of ZnIn2S4 quantum dots is 20% - 60%.

[0010] In a preferred embodiment of the present invention, the dosage ratio of NaOH to ethanol and water is 1.0 g - 1.2 g: 100 mL.

[0011] In a preferred embodiment of the present invention, the mass ratio of 1,4-diacetylbenzene to NaOH is 0.34 - 0.36: 1.

[0012] In a preferred embodiment of the present invention, the dosage ratio of ammonia water, 2,5-dimethoxy-1,4-dicarbaldehyde to NaOH is 5 mL: 0.19 g - 0.20 g: 1.0 g - 1.2 g.

[0013] In a preferred embodiment of the present invention, the preparation method of ZnIn2S4 quantum dots comprises the following steps: dissolving a soluble Zn salt, a soluble In salt and GSH in water, performing ultrasonic treatment, then adjusting the pH with an alkali solution to obtain a mixed solution, heating the mixed solution and adding Na2S, performing hydrothermal reaction, and obtaining ZnIn2S4 quantum dots through post-treatment.

[0014] In a preferred embodiment of the present invention, the molar ratio of the soluble Zn salt, the soluble In salt and GSH is 0.1 - 0.2:0.7 - 0.9:1.9 - 2.1, the dosage ratio of the soluble Zn salt to water is 0.1 mmol:35 mL - 45 mL, and the molar ratio of Na2S to the soluble Zn salt is 2:0.1 - 0.2.

[0015] In a preferred embodiment of the present invention, the hydrothermal reaction temperature is 85°C - 95°C, the hydrothermal reaction time is 1 h, the alkali solution for adjusting the pH is NaOH, and the pH is adjusted to 8.5.

[0016] Another object of the present invention is to provide a ZIS / NaCOF-2 catalyst prepared by the preparation method described in any one of the above.

[0017] The third object of the present invention is to provide an application of the above-mentioned ZIS / NaCOF-2 catalyst in photocatalytic production of H2O2.

[0018] Compared with the prior art, the beneficial effects of the present invention are: 1. In the present invention, NaOH is dissolved in a mixed solvent of ethanol and water, and then 1,4-diacetylbenzene is added to obtain a mixed solution. Next, ammonia water and 2,5-dimethoxy-1,4-dicarbaldehyde are added to the mixed solution, and the mixture is stirred at room temperature to obtain the NaCOF-2 organic framework material. Then, the NaCOF-2 organic framework material and ZnIn2S4 quantum dots are ground and mixed in absolute ethanol, and after drying, the ZIS / NaCOF-2 catalyst is obtained. The reason why the ZIS / NaCOF-2 catalyst prepared in the present invention has a high efficiency for photocatalytic production of H2O2 mainly lies in the formation of an S-scheme heterojunction. This special structure promotes the effective separation of photo-generated electrons and holes, reduces the recombination of electron-hole pairs, and thus increases the number of electrons participating in the reduction reaction to generate H2O2. Specifically, the S-scheme heterojunction is composed of two semiconductors with staggered energy bands, and a built-in electric field is formed at the interface. This electric field accelerates the separation and transport of carriers, enabling more photo-generated electrons to participate in the reaction for generating H2O2. Therefore, the ZIS / NaCOF-2 catalyst significantly improves the efficiency of photocatalytic production of H2O2 by forming an S-scheme heterojunction. Moreover, the preparation method of the present invention is simple, the reaction conditions are mild, and by optimizing the structure of the catalyst, the absorption efficiency of sunlight is improved, the recombination rate of photo-generated carriers is reduced, and the selectivity for H2O2 is enhanced.

[0019] 2. As a semiconductor catalyst that is easy to prepare, non-toxic, and has good visible light response, ZnIn2S4 quantum dots have excellent photocatalytic performance and are widely used in the fields of photocatalytic water splitting for hydrogen production, photocatalytic degradation of pollutants, and photocatalytic reduction of CO2. And the NaCOF-2 prepared in the present invention, as an organic framework material, has excellent pore structure, appropriate specific surface area, and tunable chemical properties, which make it a potential catalyst or catalyst support in the field of photocatalysis. In the present invention, ZIS and NaCOF-2 are prepared into the ZIS / NaCOF-2 catalyst by grinding and mixing. During the grinding process, ZnIn2S4 nanoparticles are uniformly dispersed in the pores or on the surface of NaCOF-2 to form a physical mixture, and this mixture can be achieved through physical forces such as van der Waals forces and electrostatic interactions. Brief Description of the Drawings

[0020] Figure 1 It is a morphology diagram of the 40% ZIS / NaCOF-2 catalyst prepared in the present invention.

[0021] Figure 2 It is an XRD pattern of the catalyst prepared in the present invention.

[0022] Figure 3 It is a photocatalytic H2O2 rate diagram under pure water conditions in the present invention.

[0023] Figure 4Photocatalytic H2O2 production rate diagrams of ZIS / NaCOF-2 of the present invention with 1 mL of benzyl alcohol added under three atmospheres.

[0024] Figure 5 Photocatalytic H2O2 production cycle experiment of 40% ZIS / NaCOF-2 of the present invention. Detailed implementation manners

[0025] The following combines the embodiments of the present invention and uses preferred embodiments and accompanying drawings for detailed description. The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0026] It should be noted that all professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the following embodiments of the present invention can be obtained through market purchases or prepared by existing methods.

[0027] Example 1 A preparation method of a ZIS / NaCOF-2 catalyst includes the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir at room temperature overnight to obtain NaCOF-2.

[0028] (2) Accurately weigh 0.1 mmol of Zn(NO3)·6H2O, 0.8 mmol of indium nitrate hydrate In(NO3)3·xH2O, and 2 mmol of glutathione (GSH), dissolve them in 40 mL of deionized water, ultrasonically treat for 10 min, and add 0.05 mol / L NaOH solution dropwise under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condenser reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol of Na2S, and continuously react at a constant temperature of 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment to collect a milky white powder, namely ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0029] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 40%.

[0030] Example 2 A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir overnight at room temperature to obtain NaCOF-2.

[0031] (2) Accurately weigh 0.1 mmol of Zn(NO3)·6H2O, 0.8 mmol of In(NO3)3·xH2O, and 2 mmol of GSH and dissolve them in 40 mL of deionized water. Ultrasonically treat for 10 min, and dropwise add 0.05 mol / L NaOH solution under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condenser reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol of Na2S, and continuously react at a constant temperature of 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment to collect a milky white powder, namely ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0032] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 50%.

[0033] Example 3 A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir overnight at room temperature to obtain NaCOF-2.

[0034] (2) Accurately weigh 0.1 mmol Zn(NO3)·6H2O, 0.8 mmol In(NO3)3·xH2O, and 2 mmol GSH, dissolve them in 40 mL of deionized water, ultrasonically treat for 10 min, dropwise add 0.05 mol / L NaOH solution under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condensing reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol Na2S, and continuously carry out a constant-temperature reaction at 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment to collect a milky white powder, namely ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0035] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 60%.

[0036] Example 4 A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir overnight at room temperature to obtain NaCOF-2.

[0037] (2) Accurately weigh 0.1 mmol Zn(NO3)·6H2O, 0.8 mmol In(NO3)3·xH2O, and 2 mmol GSH, dissolve them in 40 mL of deionized water, ultrasonically treat for 10 min, dropwise add 0.05 mol / L NaOH solution under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condensing reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol Na2S, and continuously carry out a constant-temperature reaction at 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment to collect a milky white powder, namely ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0038] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 30%.

[0039] Example 5 A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir at room temperature overnight to obtain NaCOF-2.

[0040] (2) Accurately weigh 0.1 mmol of Zn(NO3)·6H2O, 0.8 mmol of In(NO3)3·xH2O, and 2 mmol of GSH and dissolve them in 40 mL of deionized water. Ultrasonically treat for 10 min, and dropwise add 0.05 mol / L NaOH solution under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condenser reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol of Na2S, and continuously react at a constant temperature of 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment to collect a milky white powder, namely ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0041] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 20%.

[0042] Comparative Example 1 A preparation method of a ZIS / NaCOF-2 catalyst, comprising the following steps: (1) Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir at room temperature overnight to obtain NaCOF-2.

[0043] (2) Accurately weigh 0.1 mmol of Zn(NO3)·6H2O, 0.8 mmol of In(NO3)3·xH2O, and 2 mmol of GSH, dissolve them in 40 mL of deionized water, sonicate for 10 min, add 0.05 mol / L NaOH solution dropwise under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condensing reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol of Na2S, and continuously react at a constant temperature of 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment. Collect the milky white powder, which is ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0044] (3) Put ZIS QDs and NaCOF-2 in a mortar, add a small amount of absolute ethanol, grind until the powders are evenly mixed, and finally dry at 60 °C for 2 h to obtain the ZIS / NaCOF-2 catalyst, where the mass percentage of ZIS QDs in the ZIS / NaCOF-2 catalyst is 10%.

[0045] Comparative Example 2 A preparation method of a NaCOF-2 catalyst includes the following steps: Weigh 1.0 g of NaOH and dissolve it in a mixed solution of 75 mL of ethanol and 25 mL of water. After the NaOH is dissolved, add 0.35 g of 1,4-diacetylbenzene, and the solution turns yellow. Then add 5 mL of ammonia water and 0.194 g of 2,5-dimethoxybenzene-1,4-dicarboxaldehyde, and stir overnight at room temperature to obtain NaCOF-2.

[0046] Comparative Example 3 A preparation method of a ZIS catalyst includes the following steps: Accurately weigh 0.1 mmol of Zn(NO3)·6H2O, 0.8 mmol of In(NO3)3·xH2O, and 2 mmol of GSH, dissolve them in 40 mL of deionized water, sonicate for 10 min, add 0.05 mol / L NaOH solution dropwise under magnetic stirring to adjust the pH to 8.5 to obtain a mixed solution. Then transfer the mixed solution to a 250 mL three-necked flask and place it in an oil bath equipped with a condensing reflux device. Under nitrogen protection and magnetic stirring, heat up to 90 °C and add 2 mmol of Na2S, and continuously react at a constant temperature of 90 °C for 1 h. After the reaction is completed, centrifuge and wash with isopropanol to obtain a white precipitate, and perform vacuum drying treatment. Collect the milky white powder, which is ZnIn2S4 quantum dots, denoted as ZIS QDs.

[0047] Result Analysis Figure 1 This is the morphology diagram of the 40% ZIS / NaCOF-2 catalyst prepared by the present invention. It can be seen from the figure that the sample presents a regular quasi-spherical structure, and its particle size distribution range is in the interval of 500 nm to 1000 nm.

[0048] Figure 2 This is the XRD pattern of the catalyst samples prepared in Examples 1 to 5 and Comparative Examples 1 to 3 of the present invention. It can be seen from the figure that ZIS and NaCOF-2 have good crystallinity. ZIS has obvious characteristic diffraction peaks at 27.9° and 48°, which respectively correspond to the (311) and (440) crystal planes of cubic phase ZIS (JCPDS No.72-0305). From the XRD pattern of ZIS / NaCOF-2, it can be seen that the characteristic pattern of the composite material basically overlaps with that of ZIS and NaCOF-2. As the amount of ZIS added gradually increases, the diffraction peak of NaCOF-2 gradually weakens, and the diffraction peak of ZIS gradually strengthens. The results show that there is close interfacial contact between ZIS and NaCOF-2, forming a heterostructure.

[0049] To explore the performance of the material for photocatalytic production of H2O2, under visible light irradiation, a photocatalytic experiment was carried out on 50 mL of deionized water with 5 mg of the catalyst. Figure 3 As can be seen, the amount of H2O2 produced by single NaCOF-2 after 1 h of photocatalysis is 1349 μmol g -1 . The performance of the composite material ZIS / NaCOF-2 for photocatalytic production of H2O2 is significantly better than that of NaCOF-2. Among them, for 10%, 20%, and 30% ZIS / NaCOF-2, due to the small amount of ZIS added, the photocatalytic performance did not reach the ideal state; while in 50% and 60% ZIS / NaCOF-2, the content of ZIS is too high to form a closed effect, resulting in a decrease in photocatalytic performance; the 40% ZIS / NaCOF-2 photocatalyst reaches the best ratio, and the effect of producing H2O2 is the best. The amount of H2O2 produced by photocatalysis for 1 h is 4359 μmol g -1 , which is 3.2 times that of pure NaCOF-2.

[0050] According to the data of photocatalytic production of H2O2, the efficiency of photocatalytic production of H2O2 in different atmospheres was explored. Figure 4 It can be seen that under air conditions, the efficiency of photocatalytic production of H2O2 by adding 1 mL of benzyl alcohol with 5 mg of 40% ZIS / NaCOF-2 is the highest, significantly higher than that in oxygen and much greater than that in argon.

[0051] To verify the stability and durability of the catalyst, a cyclic test of photocatalytic production of H2O2 was carried out on 5 mg of 40% ZIS / NaCOF-2 added with 1 mL of benzyl alcohol under air conditions.Figure 5 It can be seen that after 6 cycles, the efficiency of photocatalytic H2O2 production remains stable with small losses.

[0052] In summary, the reason why the ZIS / NaCOF-2 catalyst prepared in this invention has high efficiency in photocatalytic H2O2 production is mainly that it forms an S-scheme heterojunction. This special structure promotes the effective separation of photo-generated electrons and holes, reduces the recombination of electron-hole pairs, and thus increases the number of electrons participating in the reduction reaction to generate H2O2. Specifically, the S-scheme heterojunction consists of two semiconductors with staggered energy bands, forming a built-in electric field at the interface. This electric field accelerates the separation and transport of carriers, enabling more photo-generated electrons to participate in the H2O2 generation reaction. Therefore, the ZIS / NaCOF-2 catalyst significantly improves the efficiency of photocatalytic H2O2 production by forming an S-scheme heterojunction. Moreover, the preparation method of this invention is simple and the reaction conditions are mild. By optimizing the structure of the catalyst, the absorption efficiency of sunlight is improved, the recombination rate of photo-generated carriers is reduced, and the selectivity for H2O2 is enhanced.

[0053] It should be noted that when the present invention involves numerical ranges, it should be understood that any value between the two endpoints of each numerical range and the two endpoints themselves can be selected. Since the steps and methods adopted are the same as those in the examples, to avoid repetition, the present invention describes the preferred examples. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0054] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A method for preparing a ZIS / NaCOF-2 catalyst, characterized in that: The following steps are involved: NaOH is dissolved in a mixed solvent of ethanol and water, and then 1,4-diacetylbenzene is added to obtain a mixed solution, and then ammonia water and 2,5-dimethoxybenzene-1,4-dicarbaldehyde are added to the mixed solution, and the mixture is stirred at room temperature to obtain NaCOF-2 through a Diels-Alder reaction; ZnIn2S4 quantum dots are prepared, and the ZnIn2S4 quantum dots and NaCOF-2 are ground and mixed in anhydrous ethanol, and then dried to obtain a ZIS / NaCOF-2 catalyst.

2. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 1, characterized in that: In the ZIS / NaCOF-2 catalyst, the mass percentage of ZnIn2S4 quantum dots is 20%~60%.

3. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 1, characterized in that: The dosage ratio of NaOH to the mixed solvent of ethanol and water is 1.0 g~1.2 g:100 mL.

4. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 1, characterized in that: The mass ratio of 1,4-diacetylbenzene to NaOH is 0.34~0.36:

1.

5. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 1, characterized in that: The dosage ratio of ammonia water, 2,5-dimethoxy-1,4-dicarbaldehyde and NaOH is 5 mL: 0.19 g~0.20 g: 1.0 g~1.2 g.

6. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 1, characterized in that: The preparation method of ZnIn2S4 quantum dots comprises the following steps: A soluble Zn salt, a soluble In salt and glutathione are mixed and dissolved in water, ultrasonically treated, and then an alkali solution is used to adjust the pH to obtain a mixed solution. The mixed solution is heated and Na2S is added to perform a hydrothermal reaction, and ZnIn2S4 quantum dots are obtained after post-treatment.

7. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 6, characterized in that: The molar ratio of soluble Zn salt, soluble In salt and GSH is 0.1~0.2:0.7~0.9:1.9~2.1, the dosage ratio of soluble Zn salt and water is 0.1mmol:35mL~45mL, and the molar ratio of Na2S to soluble Zn salt is 2:0.1~0.

2.

8. The method for preparing the ZIS / NaCOF-2 catalyst according to claim 6, characterized in that: The hydrothermal reaction temperature is 85°C~95°C, and the hydrothermal reaction time is 1 h.

9. A ZIS / NaCOF-2 catalyst, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. Use of the ZIS / NaCOF-2 catalyst according to claim 9 in photocatalytic production of H2O2.

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