Preparation method and application of ternary composite photocatalyst of dual-promoted NH2-MIL-125

Abstract

The application discloses a preparation method of a NH2-MIL-125 ternary composite photocatalyst regulated by a double assistant catalyst and application thereof. An ionic liquid is used as a carbon source and a modifier, and under the condition of phosphoric acid, 190 DEG C reaction is carried out for 4 days, and after purification, a CDs solution is obtained; 2-amino terephthalic acid and tetrabutyl titanate are used as raw materials, DMF and anhydrous methanol are used as solvents, and 150 DEG C reaction is carried out for 8 hours, and NH2-MIL-125 is obtained; through an impregnation method, an assistant catalyst Pt and CDs are loaded on NH2-MIL-125 to obtain a CDs-Pt / NH2-MIL-125 ternary composite photocatalyst. The preparation method is simple, convenient and good in reproducibility, and compared with the existing NH2-MIL-125-based photocatalyst, the prepared CDs-Pt / NH2-MIL-125 ternary composite photocatalyst has higher catalytic activity and good reusability in a photocatalytic water decomposition hydrogen production reaction process, and the hydrogen production rate reaches 3805.6 mu mol / g / h.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ternary composite photocatalysts for catalytic decomposition of water to produce hydrogen, and particularly relates to a preparation method of a NH2-MIL-125 ternary composite photocatalyst with double-assisted catalyst regulation and application thereof. BACKGROUND

[0002] Excessive use of fossil energy can cause serious environmental pollution and energy crisis. In order to reduce the consumption of non-renewable energy, the use of green and renewable clean energy has become the focus. Hydrogen energy has become a kind of green and renewable energy with great potential due to its high energy density, high calorific value, zero carbon emission and other advantages. There are many ways to produce hydrogen, such as thermal catalysis, electrocatalysis and photocatalysis. Among them, photocatalytic decomposition of water is considered an ideal way to produce hydrogen, which has the advantages of low cost, environmental friendliness, safety and harmlessness. At present, common photocatalysts include metal sulfides (CdS, Zn2InS4), metal oxides (TiO2, Co3O4), metal organic frameworks (MOFs) (NH2-MIL-125, UiO-66) and layered double hydroxides (LDHs). However, most of the photocatalysts have problems such as easy corrosion by light, narrow light response range, and low photocatalytic activity. Therefore, it is of great significance to develop new high-efficiency and structure-stable photocatalysts.

[0003] MOFs are a kind of porous organic polymers formed by coordination bonds between organic ligands and metal ions or metal clusters, which have the advantages of large specific surface area, adjustable structure and large porosity. Among a series of MOFs, NH2-MIL-125 has been widely used in the field of photocatalysis due to its low price, low toxicity and good redox ability. At the same time, the presence of electron-donating group -NH2 can significantly reduce the energy band gap (2.6eV) of NH2-MIL-125, so that the light absorption range of NH2-MIL-125 is expanded from the ultraviolet region (about 7%) to the visible light region (about 46%).

[0004] However, the NH2-MIL-125 still has the problem of low photocatalytic activity due to the easy recombination of photo-generated electron-hole pairs. Existing reports show that some carbon-based materials can act as cocatalysts or electron mediators to enhance the photocatalytic activity of MOFs. Carbon dots (CDs) are a class of zero-dimensional carbon nanomaterials with a size of less than 10 nm. They have attracted widespread attention due to their good biocompatibility, low toxicity, high electrical conductivity, and unique optical properties. After researching the literature, it was found that the existing CDs photocatalysts are all synthesized by using biomass (glucose, citric acid, etc.) as a carbon source. For example, He Youzhou et al. synthesized a bifunctional CDs / NH2-MIL-125 composite photocatalyst by using glucose as a carbon source. The catalyst has high photocatalytic activity. It can be used for photocatalytic decomposition of water to produce hydrogen, and can also effectively oxidize nitric oxide gas to generate nitrite and nitrate. (Y. He, S. Luo, X. Hu, Y. Cheng, Y. Huang, S. Chen, M. Fu, Y. Jia, X. Liu. Chem. Eng. J., 2021, 420, No. 127643). Zhang Fengming et al. combined g-C3N4 and NH2-UiO-66 to prepare NH2-UiO-66@g-C3N4 composite material, then immersed it in glucose solution and calcined under nitrogen atmosphere to obtain CDs / NH2-UiO-66@g-C3N4 photocatalyst. The hydrogen production rate of the catalyst is 17.5 times that of the undoped carbon dot material (X. Zhang, H. Dong, X. Sun, D. Yang, J. Sheng, H. Tang, X. Meng, F. Zhang. ACS Sustain. Chem. Eng., 2018, 6, 11563-11569). However, so far, there is no related literature report on the synthesis of CDs by using “green solvent” ionic liquid as a carbon source and modifier, and the use of the CDs and nano-Pt as double cocatalysts to regulate NH2-MIL-125 to obtain ternary composite photocatalyst CDs / Pt-NH2-MIL-125 for photocatalytic decomposition of water to produce hydrogen.

[0005] Therefore, it is of great significance to develop a double cocatalyst-regulated CDs-Pt / NH2-MIL-125 ternary composite photocatalyst with high activity, good stability and recyclable use, and to use it for efficient photocatalytic decomposition of water to produce hydrogen. SUMMARY

[0006] This section is intended to introduce the reader to some aspects of the embodiments of the present application and to relate them to the background art so that the novel aspects of the present application can be better understood and appreciated. However, nothing in this section should be taken as an indication that any particular aspect of the present application does not pertain to the prior art.

[0007] In view of the above and / or other problems existing in the prior art, the present application is proposed.

[0008] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and provide a preparation method of a NH2-MIL-125 ternary composite photocatalyst with dual cocatalyst regulation.

[0009] To solve the above technical problems, the present application provides the following technical scheme: a preparation method of a NH2-MIL-125 ternary composite photocatalyst with dual cocatalyst regulation, comprising,

[0010] Mixing the ionic liquid and the phosphoric acid solution uniformly, adding them into a hydrothermal kettle, reacting at 180-190 DEG C for 2-4 days, adjusting the pH of the solution to 7, and preparing a crude product CD solution;

[0011] Transferring the crude product CDs into a dialysis bag, then adding them into a container containing water for dialysis, and obtaining a CDs solution;

[0012] Dissolving 2-amino terephthalic acid in a mixed solution of DMF and anhydrous methanol, adding tetrabutyl titanate, stirring uniformly to obtain a mixed solution, transferring the mixed solution into a hydrothermal kettle, reacting at 150-160 DEG C for 6-8 hours, washing with DMF and anhydrous methanol, and drying to obtain NH2-MIL-125;

[0013] Adding a cocatalyst Pt, the CDs solution and the NH2-MIL-125 into anhydrous ethanol, fully immersing and stirring at room temperature, and obtaining a CDs-Pt / NH2-MIL-125 ternary composite photocatalyst.

[0014] As a preferred scheme of the preparation method of the present application, the ionic liquid is one or more of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium bistrifluoromethylsulfonylimide and 1-butyl-3-methylimidazolium tetrafluoroborate.

[0015] As a preferred scheme of the preparation method of the present application, the volume ratio of the ionic liquid and the phosphoric acid solution is 1:1-5:1.

[0016] As a preferred scheme of the preparation method of the present application, the mixed solution of DMF and anhydrous methanol, wherein the volume ratio of DMF and anhydrous methanol is 8:1-8:15.

[0017] As a preferred scheme of the preparation method, the 2-amino terephthalic acid is dissolved in a mixed solution of DMF and anhydrous methanol, and tetrabutyl titanate is added, wherein the ratio of 2-amino terephthalic acid to DMF is 0.21g-0.31g:8mL, and the ratio of 2-amino terephthalic acid to tetrabutyl titanate is 0.21g-0.31g:225μL.

[0018] As a preferred scheme of the preparation method, the 2-amino terephthalic acid is dissolved in a mixed solution of DMF and anhydrous methanol, and tetrabutyl titanate is added, wherein the ratio of 2-amino terephthalic acid to DMF is 0.21g-0.31g:8mL, and the ratio of 2-amino terephthalic acid to tetrabutyl titanate is 0.21g-0.31g:225μL.

[0019] Still another object of the present application is to overcome the deficiencies in the prior art and provide a NH2-MIL-125 ternary composite photocatalyst regulated by double cocatalysts.

[0020] Another object of the present application is to overcome the deficiencies in the prior art and provide an application of the ternary composite photocatalyst in the preparation of hydrogen by photocatalytic decomposition of water, comprising,

[0021] In the quartz reactor, the ternary composite photocatalyst, the sacrificial agent, acetonitrile and water are added, and the reaction is carried out under visible light for 4-6h to obtain hydrogen.

[0022] As a preferred scheme of the application, the sacrificial agent is one or more of triethanolamine, methanol and eosin Y; 1-4mg of photocatalyst is added per 1ml of water; and 0.1-7.0ml of sacrificial agent is added per 1ml of water.

[0023] As a preferred scheme of the application, the yield of the obtained hydrogen is as high as 3805.6μmol / g / h.

[0024] The present application has the following advantages:

[0025] (1) The present application uses "green solvent" ionic liquid as carbon source and modifier, synthesizes CDs by hydrothermal method, regulates NH2-MIL-125 by CDs and nano-Pt as double cocatalysts, and prepares CDs-Pt / NH2-MIL-125 ternary composite photocatalyst by impregnation method, which has the advantages of high activity, good light stability and good reproducibility.

[0026] (2) The synthesized CDs-Pt / NH2-MIL-125 ternary composite photocatalyst has a large specific surface area, which is conducive to the adsorption of water molecules; at the same time, the mesoporous structure contained in NH2-MIL-125 is also conducive to the adsorption and diffusion of the reactants; the nano-metal Pt and CDs act as double catalysts in the reaction process, on the one hand, Pt and NH2-MIL-125 form a coordination effect, promoting the rapid transfer of photo-generated electrons to the surface of Pt for reduction reaction to generate hydrogen; on the other hand, CDs act as an electron medium, which plays a role in stabilizing and activating Pt, the addition of CDs promotes more photo-generated electrons to migrate to the surface of Pt, accelerating the production of hydrogen, and the synergistic catalysis can significantly improve the photocatalytic activity of CDs-Pt / NH2-MIL-125.

[0027] (3) The CDs-Pt / NH2-MIL-125 ternary composite photocatalyst prepared in the application has high photocatalytic performance, and the hydrogen production rate is as high as 3805.6 μmol / g / h, which has certain potential in the application of solar hydrogen production. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art. Among them:

[0029] Figure 1 X-ray powder diffraction (XRD) spectra of NH2-MIL-125, Pt / NH2-MIL-125 and CDs100-Pt / NH2-MIL-125 prepared in Example 1 of the application;

[0030] Figure 2 Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) diagrams of NH2-MIL-125, CDs, and CDs100-Pt / NH2-MIL-125 prepared in Example 1 of the application;

[0031] Figure 3 Photocatalytic water decomposition hydrogen production diagram of NH2-MIL-125, Pt / NH2-MIL-125 and CDs100-Pt / NH2-MIL-125 prepared in Example 1 of the application;

[0032] Figure 4 Catalytic effect diagram of CDs100-Pt / NH2-MIL-125 prepared in Example 1 of the application for five times of photocatalytic water decomposition hydrogen production. DETAILED DESCRIPTION

[0033] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the description examples.

[0034] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific examples disclosed below.

[0035] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is separate or alternative to other embodiments.

[0036] The specifications of the chemical reagents used in the experiments of the present application are shown in Table 1.

[0037] Table 1

[0038]

[0039] The model numbers of the instruments and equipment used in the experiments of the present application are shown in Table 2.

[0040] Table 2

[0041]

[0042]

[0043] Example 1

[0044] (1) 10 mL of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190℃ for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D), and then added to a beaker containing water for dialysis to obtain a CDs solution; TEM characterization test results showed that the CDs were successfully prepared.

[0045] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to a hydrothermal kettle with a polytetrafluoroethylene lining, and reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The characterization test results by SEM and XRD showed that NH2-MIL-125 was successfully prepared.

[0046] (3) Finally, by excess impregnation method, 5 mg of promoter Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, and fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The characterization test results by XRD showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0047] The CDs, NH2-MIL-125, Pt / NH2-MIL-125, and CDs100-Pt / NH2-MIL-125 prepared in Example 1 were characterized.

[0048] A MiniFlex600 X-ray powder diffractometer (PXRD, Cu Kα radiation, λ = 0.15406 nm, scanning range 2θ 5°-60°) was used to analyze the crystal structure and crystal phase of NH2-MIL-125, Pt / NH2-MIL-125, and CDs100-Pt / NH2-MIL-125.

[0049] The test results are shown in Table 1. Figure 1 As shown in Table 1, the results showed that, in terms of peak intensity, the peak intensity of NH2-MIL-125 was strong and the peak shape was very sharp, indicating that NH2-MIL-125 had good crystallinity. From the XRD pattern of Pt / NH2-MIL-125, it can be seen that the characteristic diffraction peaks of Pt species were at 39.78° and 46.33°, indicating the successful loading of Pt on NH2-MIL-125. From the XRD pattern of CDs100-Pt / NH2-MIL-125, it can be seen that after CDs and Pt were loaded on NH2-MIL-125, NH2-MIL-125 still had very high crystallinity, indicating that NH2-MIL-125 had good stability and CDs and Pt had high dispersity on NH2-MIL-125.

[0050] TESCAN-field emission scanning electron microscope and FEI Talos F200X transmission electron microscope were used to analyze the morphology and crystal structure of NH2-MIL-125, CDs, CDs100-Pt / NH2-MIL-125. As shown in Fig. Figure 2 a, NH2-MIL-125 presents uniform size, about 500 nm in size, in the form of round sheet. In addition, it can be seen from the figure that the crystal phase of NH2-MIL-125 is relatively pure, without other impure amorphous phase, and the morphology and structure are relatively regular. From the transmission electron microscope Figure 2 b of CDs, it can be seen that CDs are spherical with a size of about 5 nm. From the transmission electron microscope Figure 2 c of CDs100-Pt / NH2-MIL-125, it can be seen that CDs and Pt are uniformly loaded on the surface of the carrier NH2-MIL-125, in which the lattice fringe spacing of CDs is 0.212 nm (100 plane), and the lattice fringe spacing of nano-Pt is 0.230 nm (111 plane), indicating the successful loading of the dual catalyst CDs and Pt on NH2-MIL-125.

[0051] Example 2

[0052] (1) 10 mL of 1-butyl-3-methyl hexafluorophosphate and 5 mL of phosphoric acid solution were mixed uniformly and transferred to a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D), and then added to a beaker containing water for dialysis to obtain a CDs solution. The test results of TEM characterization show that CDs are successfully prepared.

[0053] (2) Secondly, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, and 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The test results of SEM and XRD characterization show that NH2-MIL-125 is successfully prepared.

[0054] (3) Finally, by excess impregnation method, 5 mg of catalyst 5Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, and fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain a ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The test results of XRD characterization show that CDs100-Pt / NH2-MIL-125 is successfully prepared.

[0055] Example 3

[0056] (1) 10 mL of 1-butyl-3-methylimidazolium tetrafluoroborate and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D), and then added to a beaker with water as the dialysate for dialysis to obtain a CDs solution. TEM characterization test results showed that the CDs were successfully prepared.

[0057] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. SEM and XRD characterization test results showed that NH2-MIL-125 was successfully prepared.

[0058] (3) Finally, 5 mg of a cocatalyst Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol by an excess impregnation method, and fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain a CDs100-Pt / NH2-MIL-125 ternary composite photocatalyst. XRD characterization test results showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0059] Example 4

[0060] (1) 7.5 mL of 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide and 7.5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D), and then added to a beaker with water as the dialysate for dialysis to obtain a CDs solution. TEM characterization test results showed that the CDs were successfully prepared.

[0061] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. SEM and XRD characterization test results showed that NH2-MIL-125 was successfully prepared.

[0062] (3) Finally, the cocatalyst 5 mg Pt and 100 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The results of XRD characterization tests showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0063] Example 5

[0064] (1) 7.5 mL of 1-butyl-3-methylimidazolium hexafluorophosphate and 7.5 mL of phosphoric acid solution were mixed uniformly and transferred to a hydrothermal kettle with a polytetrafluoroethylene liner, which was reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000 D) and then added to a beaker of dialysis fluid, which was water, for dialysis to obtain a CDs solution. The results of TEM characterization tests showed that CDs were successfully prepared.

[0065] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of absolute methanol, and 225 μΐ of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to a hydrothermal kettle with a polytetrafluoroethylene liner, which was reacted at 150 °C for 8 hours; washed with DMF and absolute methanol and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0066] (3) Finally, the cocatalyst 5 mg Pt and 100 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The results of XRD characterization tests showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0067] Example 6

[0068] (1) 7.5 mL of 1-butyl-3-methylimidazolium tetrafluoroborate and 7.5 mL of phosphoric acid solution were mixed uniformly, transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000 D) and then added to a beaker containing water as the dialysate for dialysis to obtain a CDs solution. TEM characterization tests showed that the CDs were successfully prepared.

[0069] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0070] (3) Finally, by excess impregnation method, 5 mg of promoter Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain a ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. XRD characterization tests showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0071] Example 7

[0072] (1) 7.5 mL of 1-butyl-3-methylimidazolium tetrafluoroborate and 7.5 mL of phosphoric acid solution were mixed uniformly, transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000 D) and then added to a beaker containing water as the dialysate for dialysis to obtain a CDs solution. TEM characterization tests showed that the CDs were successfully prepared.

[0073] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0074] (3) Finally, the cocatalyst 5 mg Pt and 100 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min, to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The result of XRD characterization test showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0075] Example 8

[0076] (1) 12.5 mL of 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt and 2.5 mL of phosphoric acid solution were mixed uniformly, transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred into a dialysis bag (MWCO: 500-1000 D), and then added to a beaker with water as the dialysate for dialysis, to obtain a CDs solution. The result of TEM characterization test showed that CDs were successfully prepared.

[0077] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 1 mL of absolute methanol, 225 μΐ of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 150 °C for 8 hours; washed with DMF and absolute methanol, and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0078] (3) Finally, the cocatalyst 5 mg Pt and 100 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min, to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The result of XRD characterization test showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0079] Example 9

[0080] (1) 12.5 mL of 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt and 2.5 mL of phosphoric acid solution were mixed uniformly, transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred into a dialysis bag (MWCO: 500-1000 D), and then added to a beaker with water as the dialysate for dialysis, to obtain a CDs solution. The result of TEM characterization test showed that CDs were successfully prepared.

[0081] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 1 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests show that NH2-MIL-125 is successfully prepared.

[0082] (3) Finally, by excess impregnation method, 5 mg of Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The results of XRD characterization tests show that CDs100-Pt / NH2-MIL-125 is successfully prepared.

[0083] Example 10

[0084] (1) 10 mL of 1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D) and then added to a beaker of dialysis fluid which was water for dialysis to obtain a CDs solution. The results of TEM characterization tests show that CDs are successfully prepared.

[0085] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 1 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests show that NH2-MIL-125 is successfully prepared.

[0086] (3) Finally, by excess impregnation method, 5 mg of Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The results of XRD characterization tests show that CDs100-Pt / NH2-MIL-125 is successfully prepared.

[0087] Example 11

[0088] (1) 10 mL of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000 D), and then added to a beaker with water as the dialysate for dialysis to obtain a CDs solution. The results of TEM characterization tests showed that the CDs were successfully prepared.

[0089] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 10 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 150 °C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0090] (3) Finally, 5 mg of a cocatalyst Pt and 100 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol by an excess impregnation method, and fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain a CDs100-Pt / NH2-MIL-125 ternary composite photocatalyst. The results of XRD characterization tests showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0091] Example 12

[0092] (1) 10 mL of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000 D), and then added to a beaker with water as the dialysate for dialysis to obtain a CDs solution. The results of TEM characterization tests showed that the CDs were successfully prepared.

[0093] (2) Next, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 15 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added, and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, and reacted at 150 °C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0094] (3) Finally, the cocatalyst 5 mg Pt and 100 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs100-Pt / NH2-MIL-125. The result of XRD characterization test showed that CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0095] Example 13

[0096] (1) 10 mL of 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, which was reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred into a dialysis bag (MWCO: 500-1000 D), which was then added to a beaker containing water as the dialysate for dialysis to obtain a CDs solution. The result of TEM characterization test showed that CDs was successfully prepared.

[0097] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in 8 mL of a mixed solution of DMF and 2 mL of absolute methanol, and 225 μΐ of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, which was reacted at 150 °C for 8 hours; washed with DMF and absolute methanol and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0098] (3) Finally, the cocatalyst 5 mg Pt and 50 μΐ, of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of absolute ethanol, which was fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs50-Pt / NH2-MIL-125. The result of XRD characterization test showed that CDs50-Pt / NH2-MIL-125 was successfully prepared.

[0099] Example 14

[0100] (1) 10 mL of 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred into a hydrothermal kettle with a polytetrafluoroethylene liner, which was reacted at 190 °C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred into a dialysis bag (MWCO: 500-1000 D), which was then added to a beaker containing water as the dialysate for dialysis to obtain a CDs solution. The result of TEM characterization test showed that CDs was successfully prepared.

[0101] (2) Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0102] (3) Finally, by excess impregnation method, 5 mg of promoter Pt and 250 μL of CDs were simultaneously loaded on 100 mg of NH2-MIL-125 in 10 mL of anhydrous ethanol, fully impregnated at room temperature and stirred at 500 rpm for 30 min to obtain the ternary composite photocatalyst CDs250-Pt / NH2-MIL-125. The results of XRD characterization tests showed that CDs250-Pt / NH2-MIL-125 was successfully prepared.

[0103] Comparative Example 1

[0104] 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 20 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was not successfully prepared.

[0105] Comparative Example 2

[0106] 10 mL of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt and 5 mL of phosphoric acid solution were mixed uniformly and transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 190°C for 4 days; the pH of the solution was adjusted to 7 with sodium hydroxide; then the crude CDs were transferred to a dialysis bag (MWCO: 500-1000D) and then added to a beaker containing water for dialysis to obtain a CDs solution. The results of TEM characterization tests showed that CDs were successfully prepared.

[0107] Second, 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to an autoclave with a polytetrafluoroethylene liner, reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The results of SEM and XRD characterization tests showed that NH2-MIL-125 was successfully prepared.

[0108] Finally, 100 μL CDs were loaded on 100 mg NH2-MIL-125 by excess impregnation method in 10 mL anhydrous ethanol, which was impregnated sufficiently at room temperature and stirred at 500 rpm for 30 min, to obtain the CDs100 / NH2-MIL-125 binary composite photocatalyst. The results of characterization test by XRD showed that the CDs100 / NH2-MIL-125 was successfully prepared.

[0109] Comparative Example 3

[0110] 0.21 g of 2-amino terephthalic acid was dissolved in a mixed solution of 8 mL of DMF and 2 mL of anhydrous methanol, 225 μL of tetrabutyl titanate was added and stirred uniformly; the above mixed solution was transferred to a hydrothermal kettle with a polytetrafluoroethylene liner, and reacted at 150°C for 8 hours; washed with DMF and anhydrous methanol, and dried to obtain NH2-MIL-125. The results of characterization test by SEM and XRD showed that the NH2-MIL-125 was successfully prepared.

[0111] Finally, 5 mg of Pt was loaded on 100 mg of NH2-MIL-125 by excess impregnation method in 10 mL of anhydrous ethanol, which was impregnated sufficiently at room temperature and stirred at 500 rpm for 30 min, to obtain the Pt / NH2-MIL-125 binary composite photocatalyst. The results of characterization test by XRD showed that the Pt / NH2-MIL-125 was successfully prepared.

[0112] Comparative Example 4

[0113] In-situ synthesis of CDs-Pt / NH2-MIL-125

[0114] 5 mg of Pt and 100 μL of 1-butyl-3-methyl imidazole bis-trifluoromethanesulfonimide salt were added to anhydrous methanol containing 100 mg of NH2-MIL-125, mixed uniformly, centrifuged, dried, and the product was collected; the product was calcined at 300°C for 3 hours under N2atmosphere to obtain the CDs100-Pt / NH2-MIL-125 ternary composite photocatalyst. The results of characterization test by XRD showed that the CDs100-Pt / NH2-MIL-125 was successfully prepared.

[0115] Example 15

[0116] The hydrogen production performance of the CDs100-Pt / NH2-MIL-125 ternary composite photocatalyst prepared in Example 1 was studied.

[0117] In a 100 mL quartz reactor, 20 mg of CDs100-Pt / NH2-MIL-125 photocatalyst, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour by gas chromatograph. The results, as shown in Table 1, show that the hydrogen production rate was as high as 3805.6 μmol / g / h. Figure 3

[0118] Test conditions:

[0119] An Agilent GC 8860 gas chromatograph system was used, with a TCD detector, a 5A molecular sieve chromatographic column, and Ar as the carrier gas. The experimental parameters were set as follows: TCD device, 200°C; vaporization chamber temperature, 210°C; chromatographic column temperature, 50°C; and carrier gas flow rate, 1.0 mL / min.

[0120] Example 16

[0121] In a 100 mL quartz reactor, 20 mg of the CDs50-Pt / NH2-MIL-125 photocatalyst prepared in Example 13, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour by gas chromatograph. The hydrogen production rate was 3289.3 μmol / g / h.

[0122] Example 17

[0123] In a 100 mL quartz reactor, 20 mg of the CDs250-Pt / NH2-MIL-125 photocatalyst prepared in Example 14, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour by gas chromatograph. The hydrogen production rate was 2963.2 μmol / g / h.

[0124] Example 18

[0125] In a 100 mL quartz reactor, 20 mg of the CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 3 (carbon source: 1-butyl-3-methylimidazolium tetrafluoroborate), 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour by gas chromatograph. The hydrogen production rate was 2507.6 μmol / g / h.

[0126] Example 19

[0127] ​In a 100 mL quartz reactor, 20 mg of CDs100-Pt / NH2-MIL-125 photocatalyst (carbon source: 1-butyl-3-methylimidazolium hexafluorophosphate) prepared in Example 2, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 2798.3 μmol / g / h.

[0128] Example 20

[0129] In a 100 mL quartz reactor, 6 mg of CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 2169.5 μmol / g / h.

[0130] Example 21

[0131] In a 100 mL quartz reactor, 24 mg of CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 2319 μmol / g / h.

[0132] Example 22

[0133] In a 100 mL quartz reactor, 20 mg of CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 1.5 mL of methanol, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 1913.6 μmol / g / h.

[0134] Example 23

[0135] In a 100 mL quartz reactor, 20 mg of CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 1.5 mL of eosin Y, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 1707.8 μmol / g / h.

[0136] Example 24

[0137] In a 100 mL quartz reactor, 20 mg of the CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 6.5 mL of triethanolamine, 22.5 mL of acetonitrile and 1 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 1508.1 μmol / g / h.

[0138] Example 25

[0139] In a 100 mL quartz reactor, 20 mg of the CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 4.5 mL of triethanolamine, 22.5 mL of acetonitrile and 3 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was 1991.4 μmol / g / h.

[0140] Example 26

[0141] Circulation of the CDs100-Pt / NH2-MIL-125 ternary composite photocatalyst

[0142] In a 100 mL quartz reactor, 20 mg of the CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Example 1, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. After the reaction, the catalyst was separated by centrifugation, washed several times with deionized water and anhydrous ethanol, and dried at 80°C for 12 hours. The dried photocatalyst was used for five cycles under the same catalytic conditions, and the catalytic effect after the fifth cycle was as shown in Table 1, which showed that the catalytic activity remained essentially unchanged after five cycles. Figure 4

[0143] Comparative Example 5

[0144] In a 100 mL quartz reactor, 20 mg of the NH2-MIL-125 photocatalyst, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added and reacted under visible light for 4 hours. The generated gas was analyzed every hour using a gas chromatograph. The hydrogen production rate was only 30 μmol / g / h. The results showed that the catalytic performance was very low when only NH2-MIL-125 was used as a photocatalyst.

[0145] Comparative Example 6

[0146] ​In a 100 mL quartz reactor, 20 mg of the CDs100 / NH2-MIL-125 binary composite photocatalyst, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added, and reacted under visible light for 4 hours. The generated gas was analyzed every 1 hour by a gas chromatograph. The hydrogen production rate was 305 μmol / g / h. The results show that when CDs100 / NH2-MIL-125 is used as a photocatalyst, CDs can play the role of a cocatalyst, but the synergistic effect of the single cocatalyst on NH2-MIL-125 is weak, resulting in lower photocatalytic performance.

[0147] Comparative Example 7

[0148] In a 100 mL quartz reactor, 20 mg of the Pt / NH2-MIL-125 binary composite photocatalyst, 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added, and reacted under visible light for 4 hours. The generated gas was analyzed every 1 hour by a gas chromatograph. The hydrogen production rate was 1475.5 μmol / g / h. The results show that the single cocatalyst Pt regulated NH2-MIL-125 has a certain photocatalytic activity, but the activity is not high.

[0149] Comparative Example 8

[0150] In a 100 mL quartz reactor, 20 mg of the CDs100-Pt / NH2-MIL-125 photocatalyst prepared in Comparative Example 4 (prepared by an in-situ synthesis method), 1.5 mL of triethanolamine, 22.5 mL of acetonitrile and 6 mL of water were added, and reacted under visible light for 4 hours. The generated gas was analyzed every 1 hour by a gas chromatograph. The hydrogen production rate was 1698.8 μmol / g / h. The hydrogen production rate of the in-situ synthesis method prepared CDs100-Pt / NH2-MIL-125 photocatalyst is lower than that of the impregnation method, because in the process of preparing the photocatalyst by the in-situ synthesis method, a part of the ionic liquid covers the active sites of the photocatalyst itself, causing the contact sites of the photocatalyst and the reaction molecule to decrease, resulting in a decrease in the hydrogen production rate.

[0151] The application discloses a preparation method of a ternary composite photocatalyst CDs-Pt / NH2-MIL-125 with CDs and Pt as a double cocatalyst regulator and application of the ternary composite photocatalyst in photocatalytic decomposition of water, and relates to the field of photocatalytic decomposition of water to produce hydrogen. The preparation method of the ternary composite photocatalyst is as follows: first, ionic liquid is used as a carbon source and a modifier, and under the condition of phosphoric acid, reaction is carried out at 190 DEG C for 4 days, and after purification, a CDs solution is obtained. Second, 2-amino terephthalic acid and tetrabutyl titanate are used as raw materials, DMF and anhydrous methanol are used as solvents, and reaction is carried out at 150 DEG C for 8 hours to obtain NH2-MIL-125. Finally, through an impregnation method, the cocatalyst Pt and the CDs are loaded on the NH2-MIL-125 to obtain the ternary composite photocatalyst CDs-Pt / NH2-MIL-125. The prepared photocatalyst has the advantages of economy, high efficiency and good light recycling stability.

[0152] The preparation method is simple, convenient and reproducible. The synergistic effect among the components in the ternary composite photocatalyst CDs-Pt / NH2-MIL-125 can promote the separation of photo-generated carriers together, and effectively improves the problems of easy recombination of carriers and low activity of NH2-MIL-125. The ternary composite photocatalyst is used for photocatalytic decomposition of water to produce hydrogen, and the rate is as high as 3805.6 micromoles per gram per hour, and the photocatalyst still maintains high photocatalytic activity after multiple recycling. Therefore, the ternary composite photocatalyst has certain industrial application prospect in the field of large-scale hydrogen production.

[0153] It should be explained that the above examples are only used to illustrate the technical solutions of the application and not to limit the application. Although the application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the application, and all should be covered in the scope of the application.

Claims

1. Application of a dual co-catalyst regulated NH2-MIL-125 ternary composite photocatalyst in the preparation of hydrogen in a photocatalytic water decomposition reaction, characterized in that: The application relates to a preparation method of a ternary composite photocatalyst. The ternary composite photocatalyst is prepared by the following steps of: uniformly mixing an ionic liquid and a phosphoric acid solution, adding the mixture into a hydrothermal kettle, reacting at 180-190 DEG C for 2-4 days, adjusting the pH value of the solution to 7, and obtaining a crude CD solution, wherein the ionic liquid is 1-butyl-3-methyl imidazole bistrifluoromethyl sulfonimide salt. The crude CDs are transferred into a dialysis bag and then added into a container containing water for dialysis, so as to obtain a CDs solution. 2-amino terephthalic acid is dissolved in a mixed solution of DMF and anhydrous methanol, tetrabutyl titanate is added, and the mixed solution is uniformly stirred and then transferred into a hydrothermal kettle, so as to react at 150-160 DEG C for 6-8 hours; the product is washed with DMF and anhydrous methanol and dried, so as to obtain NH2-MIL-125. A cocatalyst Pt, a CDs solution and NH2-MIL-125 are added into anhydrous ethanol, and the mixture is fully immersed and stirred at room temperature, so as to obtain a ternary composite photocatalyst CDs-Pt / NH2-MIL-125. The volume ratio of the ionic liquid to the phosphoric acid solution is 1:1-5:

1. The mixed solution of DMF and anhydrous methanol, wherein the volume ratio of DMF to anhydrous methanol is 8:1-8:

15.

2. Use according to claim 1, characterized in that: The 2-amino terephthalic acid is dissolved in the mixed solution of DMF and anhydrous methanol, and tetrabutyl titanate is added, wherein the ratio of 2-amino terephthalic acid to DMF is 0.21-0.31 g:8 mL, and the ratio of 2-amino terephthalic acid to tetrabutyl titanate is 0.21-0.31 g:225 muL.

3. The use according to claim 1, characterized in that: The cocatalyst Pt, the CDs solution and NH2-MIL-125 are added into anhydrous ethanol, wherein the anhydrous ethanol is 10 mL, the cocatalyst Pt is 1-10 mg, the CDs solution is 50-250 muL, and NH2-MIL-125 is 100 mg; and the mixture is fully immersed and stirred at room temperature, wherein the stirring time is 30 min, and the stirring speed is 500 rpm-800 rpm.

4. The use according to claim 1, characterized in that: The sacrificial agent is one or more of triethanolamine, methanol and eosin Y; 1-4 mg of the photocatalyst is added into 1 mL of water; and 0.1-7.0 mL of the sacrificial agent is added into 1 mL of water.

5. The use according to claim 1, characterized in that: The yield of the obtained hydrogen gas reaches 3805.6 muL / g / h.

6. The use according to claim 1, characterized in that: ​ 7. The use according to claim 1, characterized in that: ​

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