A lead-rich halide perovskite bonded molybdenum disulfide photocatalytic material, a synthesis method and application thereof

Abstract

The application relates to the field of new energy and photocatalysis technology, in particular to a kind of lead-rich halide perovskite bonded molybdenum disulfide photocatalytic material and its synthesis method and application, the synthesis method, by adjusting the proportion of synthesis raw material halogenated formamidine, lead halide and mixed acid solution, using saturated solution coprecipitation method to synthesize formamidine lead halide perovskite with rich lead sites on the surface, then through the formamidine lead halide perovskite surface exposes rich lead sites and the sulfur ion in the co-catalyst molybdenum disulfide close contact, and bond to form stable lead-sulfur bond, the interface strong chemical bond greatly promotes carrier separation and transmission, so that the synthesized photocatalytic material can realize efficient photocatalytic decomposition of hydrogen halide acid to produce hydrogen. The synthesis method of the photocatalytic material has the advantages of simple preparation method, mild reaction condition, low cost and large-scale preparation, and the synthesized photocatalytic material has the advantages of high catalytic activity, and when applied to photocatalytic hydrogen production, it has the advantage of high hydrogen production activity.

Description

Technical Field

[0001] This invention relates to the fields of new energy and photocatalysis technology, specifically to a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material, its synthesis method, and its application. Background Technology

[0002] Hydrogen energy, as a clean, high-energy-density, and renewable energy source, will play an important role in the future energy structure. Hydrogen production through water splitting is considered one of the most environmentally friendly and sustainable strategies. However, due to the high energy barrier of water splitting, current research shows that the conversion efficiency of solar energy to hydrogen is far below commercial requirements.

[0003] Furthermore, halide perovskites possess excellent photoelectric properties, including narrow and suitable band gaps, high absorption coefficients, and long carrier diffusion lengths, making them ideal photocatalytic materials. Simultaneously, utilizing halide perovskite photocatalysts to catalyze the cracking of hydrogen halides (HX, X = Br-, I-) to produce hydrogen makes the conversion of solar energy into hydrogen energy more readily achievable, providing a promising new pathway to replace water splitting for hydrogen production. This not only enables the conversion of solar energy into hydrogen energy but can also be coupled with the charging reaction of hydrogen halide flow batteries, thus holding significant importance for solar energy collection, storage, and conversion into chemical and electrical energy.

[0004] However, current research shows that the photocatalytic hydrogen evolution activity of hydrogen halide decomposition remains low. The photogenerated carriers produced by halide perovskite photocatalysis cannot be effectively separated and transported, significantly limiting its photocatalytic efficiency. Although researchers have attempted to improve photocatalytic efficiency through modifications such as compositional regulation, surface loading, and heterojunction construction of halide perovskites, these modifications have limited impact on efficiency improvement due to the persistent lack of effective reaction sites on the halide perovskite surface, failing to unleash the full potential of halide perovskite photocatalysis. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the first objective of this invention is to provide a method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material. This method has the advantages of being simple, having mild reaction conditions, being low in cost, and being able to be prepared on a large scale. Furthermore, the synthesized photocatalytic material has the advantage of high catalytic activity.

[0006] The second objective of this invention is to provide a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material that can generate strong lead-sulfur bonds on the surface, exhibits excellent stability, and has advantages such as efficient charge separation, abundant hydrogen production active sites, and a small HX splitting energy barrier.

[0007] The third objective of this invention is to provide an application of a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material that can be used for photocatalytic hydrogen production and has efficient and stable photocatalytic hydrogen production activity.

[0008] To achieve the first objective of the invention, the technical solution adopted by the present invention is as follows:

[0009] This invention provides a method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material, comprising the following steps:

[0010] S1. Synthesis of formamidine halide: Formamidine acetate was added to a hydrohalic acid solution and ultrasonically dispersed, then heated and stirred to react. After removing the solvent, washing, and drying, formamidine halide was obtained.

[0011] S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: The excess formamidine halide and lead halide obtained in step S1 are added to a mixed acid solution composed of hydrohalic acid and hypophosphoric acid solution, and the mixture is heated and stirred to react. After cooling, the solid and liquid are separated by centrifugation to obtain formamidine lead halide perovskite and saturated mixed acid solution.

[0012] S3. Preparation of molybdenum disulfide: Molybdate and sulfur source are added to water and stirred to dissolve, followed by hydrothermal reaction. The mixture is then centrifuged, washed, and dried to obtain molybdenum disulfide.

[0013] S4. Synthesis of photocatalytic material: The formamidinium lead halide perovskite synthesized in step S2 and the molybdenum disulfide obtained in step S3 are added to the saturated mixed acid solution obtained in step S2 for heating and stirring reaction. After cooling, centrifugation and drying, FAPbX3 / MoS2 photocatalytic material is obtained, which is the lead halide perovskite bonded molybdenum disulfide photocatalytic material.

[0014] The saturated mixed acid solution obtained in step S2 is a mixed acid solution saturated with formamidinium lead halide perovskite.

[0015] This invention discloses a method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material. By adjusting the ratio of the raw materials—formamidinium halide, lead halide, and mixed acid solution—a formamidinium lead halide perovskite with abundant lead sites on its surface is synthesized using a saturated solution co-precipitation method. The abundant lead sites exposed on the surface of the formamidinium lead halide perovskite then come into close contact with sulfur ions in the co-catalyst molybdenum disulfide, forming stable lead-sulfur bonds. These strong interfacial bonds greatly promote carrier separation and transport, thus enabling the synthesized photocatalytic material to achieve highly efficient photocatalytic decomposition of hydrogen halides to produce hydrogen. This method offers advantages such as simple preparation, mild reaction conditions, low cost, and large-scale production capability, and the synthesized photocatalytic material exhibits high catalytic activity.

[0016] Furthermore, in step S1, the mass-to-volume ratio of formamidine acetate to the hydrohalic acid solution is 1 g:(1.5-2) mL; and / or

[0017] The mass concentration of the hydrohalic acid solution is 45% to 48%; and / or

[0018] The hydrohalic acid solution includes one or a combination of two of hydrobromic acid or hydroiodic acid.

[0019] Furthermore, in step S1, the ultrasonic dispersion time is 5 min to 15 min, the heating temperature is 55℃ to 65℃, and the reaction time is 1.5 h to 2.5 h.

[0020] Furthermore, in step S2, the molar ratio of formamidine halide to lead halide is (0.7–0.95):1; and / or

[0021] The mass-to-volume ratio of the formamidine halide to the mixed acid solution is (3-10) g: (50-100) mL; and / or

[0022] In the mixed solution of hydrohalic acid and hypophosphite, the volume ratio of hydrohalic acid to hypophosphite is 4:(0.5-1); and / or

[0023] The heating temperature is 60℃~80℃, and the reaction time is 1h~1.5h.

[0024] Furthermore, in step S3, the molybdate is one or a combination of sodium molybdate or potassium molybdate; and / or

[0025] The sulfur source is one or a combination of two of thioacetamide or thiourea; and / or

[0026] The molar ratio of molybdate to sulfur source is 1:(6-8); or / or

[0027] The hydrothermal reaction temperature is 180℃~220℃, and the hydrothermal reaction time is 20h~28h.

[0028] Furthermore, in step S4, the mass ratio of formamidinium lead halide perovskite to molybdenum disulfide is (2.5–100):1; and / or

[0029] The mass concentration of the formamidinium lead halide perovskite in the saturated mixed acid solution is 1 g / L to 4 g / L; and / or

[0030] The heating reaction temperature is 50℃~80℃, and the reaction time is 1.5h~2.5h.

[0031] To achieve the second objective of the invention, the technical solution adopted by the present invention is as follows:

[0032] This invention provides a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material, which is prepared by the above-described synthesis method of a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material.

[0033] This invention discloses a photocatalytic material of lead-rich halide perovskite bonded with molybdenum disulfide. Due to the formation of strong lead-sulfur bonds on the surface of the formamidinium lead halide perovskite after contact with molybdenum disulfide, this photocatalytic material exhibits advantages such as efficient charge separation, abundant hydrogen-producing active sites, and a low hydrogen halide splitting energy barrier. It can achieve efficient and stable photocatalytic hydrogen production, with an optimal hydrogen production performance reaching 14000 μmol g / g. -1 h -1 It also has excellent stability.

[0034] To achieve the third objective of the invention, the technical solution adopted by the present invention is as follows:

[0035] This invention provides an application of a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material in the photocatalytic decomposition of hydrogen halides to produce hydrogen.

[0036] This photocatalytic material can be applied to photocatalytic hydrogen production and has efficient and stable photocatalytic hydrogen production activity.

[0037] This invention provides a method for photocatalytic decomposition of hydrogen halides to produce hydrogen. The method utilizes the aforementioned lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material to photocatalytically decompose hydrogen halides to produce hydrogen. The method includes the following steps: dispersing the photocatalytic material in the saturated mixed acid solution, removing air by evacuation, and using a xenon lamp as a light source to photocatalytically decompose the hydrogen halides in the saturated mixed acid solution to produce hydrogen gas.

[0038] Furthermore, the mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is (1-5) mg: 1 mL; and / or

[0039] The xenon lamp has a power of 250W to 350W. It is equipped with an AM 1.5 filter with a wavelength of 420 < λ < 780nm.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] (1) A method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material involves adjusting the ratio of the raw materials formamidine halide, lead halide, and mixed acid solution, and synthesizing formamidine lead halide perovskite with abundant lead sites on its surface using a saturated solution co-precipitation method. The abundant lead sites exposed on the surface of the formamidine lead halide perovskite then come into close contact with the sulfur ions in the cocatalyst molybdenum disulfide, forming stable lead-sulfur bonds. The strong interfacial chemical bonds greatly promote carrier separation and transport, thus enabling the synthesized photocatalytic material to achieve highly efficient photocatalytic decomposition of hydrogen halides to produce hydrogen. This method for synthesizing the photocatalytic material has the advantages of simple preparation, mild reaction conditions, low cost, and large-scale production capability, and the synthesized photocatalytic material exhibits high catalytic activity.

[0042] (2) The photocatalytic material of lead-rich halide perovskite bonded with molybdenum disulfide of the present invention has the advantages of high efficiency of charge separation, abundant hydrogen production active sites and low hydrogen halide acid splitting energy barrier, due to the formation of strong lead-sulfur bonds on the surface of molybdenum disulfide after contact between the lead-rich layer on the surface of formamidinium lead halide perovskite and molybdenum disulfide. It can achieve efficient and stable photocatalytic hydrogen production, with the optimal hydrogen production performance reaching 14000 μmol g. -1 h -1 It also exhibits excellent stability due to the chemically bonded co-catalyst molybdenum disulfide.

[0043] (3) The application of a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material of the present invention in the photocatalytic decomposition of hydrogen halides to produce hydrogen. The photocatalytic material can be applied to photocatalytic hydrogen production. Because the photocatalytic material loads more co-catalyst molybdenum disulfide through strong lead-sulfur bonds, it generates more reaction sites, enhances the separation and transport efficiency of photogenerated carriers, and can effectively improve the photocatalytic performance of halide perovskite. Therefore, the photocatalytic material has efficient and stable photocatalytic hydrogen production activity when applied to photocatalytic hydrogen production. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 These are X-ray powder diffraction patterns of formamidinium lead halide perovskite prepared in Examples 1-3 and Comparative Examples 1-2 of this invention.

[0046] Figure 2 These are the ultraviolet-visible absorption spectra of formamidinium lead halide perovskites prepared in Examples 1-3 and Comparative Examples 1-2 of this invention.

[0047] Figure 3 These are electromotive force diagrams of formamidinium lead halide perovskite prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention, and molybdenum disulfide in Example 1.

[0048] Figure 4 This is a scanning electron microscope energy scattering elemental distribution map of formamidinium lead halide perovskite prepared in Example 1 of the present invention.

[0049] Figure 5 This is an X-ray powder diffraction pattern of FAPbBr3-0.9, MoS2, and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0050] Figure 6 The images show the UV-Vis absorption spectra and optical photographs of FAPbBr3-0.9, MoS2, and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention. Figure 6 In the middle, the physical optical photographs in the lower left corner refer to 20% MoS2 / FAPbBr3-0.9, FAPbBr3-0.9, and MoS2 from top to bottom.

[0051] Figure 7 This is a scanning electron microscope image of FAPbBr3-0.9 prepared in Example 1 of this invention.

[0052] Figure 8 This is a scanning electron microscope image of 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0053] Figure 9 This is a scanning electron microscope energy scattering elemental distribution map of 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0054] Figure 10 The infrared spectra of FAPbBr3-0.9, MoS2, and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention are shown.

[0055] Figure 11 The images show the Raman spectra of FAPbBr3-0.9, MoS2, and 20% MoS2 / FAPbBr3-0.9 obtained in Example 1 of this invention.

[0056] Figure 12 This is the bromine element spectrum in the X-ray photoelectron spectroscopy of FAPbBr3-0.9 and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0057] Figure 13This is the molybdenum element spectrum in the X-ray photoelectron spectroscopy of MoS2 and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0058] Figure 14 These are the photocatalytic hydrogen production activity diagrams of 20% MoS2 / FAPbBr3 prepared in Examples 1-3 and Comparative Examples 1-2 of this invention.

[0059] Figure 15 This is a stability diagram of the photocatalytic hydrogen production cycle of 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention.

[0060] Figure 16 The diagram shows the photocatalytic hydrogen production activity of MoS2, 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 of this invention, FAPbBr3-0.9 / Pt in Comparative Example 1, and FAPbBr3-0.9 in Comparative Example 2.

[0061] Figure 17 This is a photocatalytic hydrogen production activity diagram of each MoS2 / FAPbBr3-0.9 obtained in Examples 1, 6-11 of this invention.

[0062] Figure 18 These are X-ray diffraction patterns of the 20% MoS2 / FAPbBr3-0.9 sample prepared in Example 1 of this invention before and after hydrogen production stability testing. Detailed Implementation

[0063] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0064] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in this invention, the embodiments, and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0065] In this embodiment of the invention, a method for synthesizing a lead-halide-rich perovskite-bonded molybdenum disulfide photocatalytic material includes the following steps:

[0066] S1. Synthesis of formamidine halide: Formamidine acetate was added to a hydrohalic acid solution and ultrasonically dispersed, then heated and stirred to react. After removing the solvent, washing, and drying, formamidine halide was obtained.

[0067] S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: The excess formamidine halide and lead halide obtained in step S1 are added to a mixed acid solution composed of hydrohalic acid and hypophosphoric acid solution, and the mixture is heated and stirred to react. After cooling, the solid and liquid are separated by centrifugation to obtain formamidine lead halide perovskite and saturated mixed acid solution.

[0068] S3. Preparation of molybdenum disulfide: Molybdate and sulfur source are added to water and stirred to dissolve, followed by hydrothermal reaction. The mixture is then centrifuged, washed, and dried to obtain molybdenum disulfide.

[0069] S4. Synthesis of photocatalytic material: The formamidinium lead halide perovskite synthesized in step S2 and the molybdenum disulfide obtained in step S3 are added to the saturated mixed acid solution obtained in step S2 for heating and stirring reaction. After cooling, centrifugation and drying, FAPbX3 / MoS2 photocatalytic material is obtained, which is the lead halide perovskite bonded molybdenum disulfide photocatalytic material.

[0070] The saturated mixed acid solution obtained in step S2 is a mixed acid solution saturated with formamidinium lead halide perovskite.

[0071] The embodiment describes a method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material. By adjusting the ratio of the raw materials—formamidinium halide, lead halide, and mixed acid solution—a formamidinium lead halide perovskite with abundant lead sites on its surface is synthesized using a saturated solution co-precipitation method. The abundant lead sites exposed on the surface of the formamidinium lead halide perovskite then come into close contact with sulfur ions in the co-catalyst molybdenum disulfide, forming stable lead-sulfur bonds. These strong interfacial bonds greatly promote carrier separation and transport, thus enabling the synthesized photocatalytic material to achieve highly efficient photocatalytic decomposition of hydrogen halides to produce hydrogen. This method offers advantages such as simple preparation, mild reaction conditions, low cost, and large-scale production capability, and the synthesized photocatalytic material exhibits high catalytic activity.

[0072] In some embodiments, in step S1, the mass-to-volume ratio of formamidine acetate to hydrohalic acid solution is 1 g:(1.5-2) mL; and / or

[0073] The mass concentration of the hydrohalic acid solution is 45% to 48%; and / or

[0074] The hydrohalic acid solution includes one or a combination of two of hydrobromic acid or hydroiodic acid.

[0075] In some embodiments, in step S1, the ultrasonic dispersion time is 5 min to 15 min, the heating temperature is 55°C to 65°C, and the reaction time is 1.5 h to 2.5 h.

[0076] In some embodiments, in step S2, the molar ratio of formamidine halide to lead halide is (0.7–0.95):1; and / or

[0077] The mass-to-volume ratio of the formamidine halide to the mixed acid solution is (3-10) g: (50-100) mL; and / or

[0078] In the mixed solution of hydrohalic acid and hypophosphite, the volume ratio of hydrohalic acid to hypophosphite is 4:(0.5-1); and / or

[0079] The heating temperature is 60℃~80℃, and the reaction time is 1h~1.5h.

[0080] In some embodiments, in step S3, the molybdate is one or a combination of sodium molybdate or potassium molybdate; and / or

[0081] The sulfur source is one or a combination of two of thioacetamide or thiourea; and / or

[0082] The molar ratio of molybdate to sulfur source is 1:(6-8); or / or

[0083] The hydrothermal reaction temperature is 180℃~220℃, and the hydrothermal reaction time is 20h~28h.

[0084] In some embodiments, in step S4, the mass ratio of formamidinium lead halide perovskite to molybdenum disulfide is (2.5–100):1; and / or

[0085] The mass concentration of the formamidinium lead halide perovskite in the saturated mixed acid solution is 1 g / L to 4 g / L; and / or

[0086] The heating reaction temperature is 50℃~80℃, and the reaction time is 1.5h~2.5h.

[0087] In this embodiment of the invention, a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material is prepared by the above-described synthesis method for a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material.

[0088] This invention discloses a photocatalytic material of lead-rich halide perovskite bonded with molybdenum disulfide. Due to the formation of strong lead-sulfur bonds on the surface of the formamidinium lead halide perovskite after contact with molybdenum disulfide, this photocatalytic material exhibits advantages such as efficient charge separation, abundant hydrogen-producing active sites, and a low hydrogen halide splitting energy barrier. It can achieve efficient and stable photocatalytic hydrogen production, with an optimal hydrogen production performance reaching 14000 μmol g / L. -1 h -1 It also has excellent stability.

[0089] In this embodiment of the invention, a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material is used in the photocatalytic decomposition of hydrogen halides to produce hydrogen.

[0090] This photocatalytic material can be applied to photocatalytic hydrogen production and has efficient and stable photocatalytic hydrogen production activity.

[0091] In this embodiment of the invention, a method for photocatalytic decomposition of hydrogen halides to produce hydrogen is a method using the aforementioned lead-halide perovskite-bonded molybdenum disulfide photocatalytic material to photocatalytically decompose hydrogen halides to produce hydrogen, comprising the following steps: dispersing the photocatalytic material in the saturated mixed acid solution, removing air by evacuation, and using a xenon lamp as a light source to photocatalytically decompose the hydrogen halides in the saturated mixed acid solution to produce hydrogen gas.

[0092] In some embodiments, the mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is (1-5) mg:1 mL; and / or

[0093] The xenon lamp has a power of 250W to 350W. It is equipped with an AM 1.5 filter with a wavelength of 420 < λ < 780nm.

[0094] The following description is based on specific embodiments.

[0095] Example 1

[0096] A method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material includes the following steps:

[0097] S1. Synthesis of formamidine halide: 10g of formamidine acetate was added to 18mL of hydrobromic acid solution (48wt% aqueous solution) and ultrasonically dispersed for 10min. The mixture was then heated to 60℃ and stirred for 2h. The product was then placed in a rotary evaporator at 60℃ to remove the solvent and obtain a crude product. The crude product was then recrystallized three times with ethanol and diethyl ether solution, washed three times with diethyl ether, and finally dried in a vacuum oven at 50℃ for 6h to obtain a white powder product, namely formamidine bromide (FABr).

[0098] S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: 18 mmol of formamidine bromide and 20 mmol of lead bromide (PbBr2) were added to a mixed acid solution consisting of 40 mL of hydrobromic acid and 10 mL of hypophosphoric acid solution. The mixture was heated to 80 °C and stirred for 1 h to reach dynamic equilibrium. After natural cooling to room temperature, the mixture was centrifuged to separate the solid and liquid phases. The precipitate obtained after centrifugation was placed in a vacuum oven at 60 °C and dried for 12 h to obtain an orange powder product, which is formamidine lead halide perovskite (denoted as FAPbBr3-0.9). A saturated solution of formamidine lead halide perovskite in mixed acid was also obtained, which is the saturated mixed acid solution.

[0099] Preparation of S3 and molybdenum disulfide: 2 mmol of Na2MoO4 and 12 mmol of thioacetamide were added to a reaction vessel containing 30 mL of deionized water and stirred for 2 h to dissolve. Then, a hydrothermal reaction was carried out in an oven at 200 °C for 24 h to obtain crude MoS2 product. The crude MoS2 product was washed three times with water and ethanol alternately, centrifuged, and then dried in a vacuum oven at 60 °C for 12 h to obtain black powder product molybdenum disulfide.

[0100] S4. Synthesis of photocatalytic material: 100 mg of formamidinium lead halide perovskite synthesized in step S2 and 20 mg of molybdenum disulfide obtained in step S3 were added to 50 mL of saturated mixed acid solution obtained in step S2 and heated to 60 °C with stirring for 2 h. Then, the mixture was cooled to room temperature while stirring was maintained. The precipitate was then collected by centrifugation and dried in a vacuum oven at 60 °C for 12 h to obtain a brown powder product, FAPbX3 / MoS2 photocatalytic material, which is the lead halide perovskite-bonded molybdenum disulfide photocatalytic material (denoted as 20%MoS2 / FAPbBr3-0.9).

[0101] Example 2

[0102] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 14 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is designated FAPbBr3-0.7, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is designated 20%MoS2 / FAPbBr3-0.7. The remaining components and preparation method are the same as in Example 1.

[0103] Example 3

[0104] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 16 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is designated FAPbBr3-0.8, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is designated 20%MoS2 / FAPbBr3-0.8. The remaining components and preparation method are the same as in Example 1.

[0105] Example 4

[0106] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 17 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is designated FAPbBr3-0.85, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is designated 20%MoS2 / FAPbBr3-0.85. The remaining components and preparation method are the same as in Example 1.

[0107] Example 5

[0108] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 19 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is designated FAPbBr3-0.95, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is designated 20%MoS2 / FAPbBr3-0.95. The remaining components and preparation method are the same as in Example 1.

[0109] Example 6

[0110] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. The difference between this embodiment and Example 1 is that 3 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 3%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0111] Example 7

[0112] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that 5 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 5%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0113] Example 8

[0114] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that 10 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 10%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0115] Example 9

[0116] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. The difference between this embodiment and Example 1 is that 15 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 15%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0117] Example 10

[0118] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that 30 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 30%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0119] Example 11

[0120] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that 40 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is designated as 40%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0121] Example 12

[0122] A method for synthesizing a lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. The difference between this embodiment and Example 1 is that 1 mg of MoS2 is added to the saturated mixed acid solution. The resulting lead-halide perovskite-bonded molybdenum disulfide photocatalytic material is denoted as 1%MoS2 / FAPbBr3-0.9. The remaining components and preparation method are the same as in Example 1.

[0123] Example 13

[0124] A method for synthesizing a photocatalytic material of lead halide perovskite bonded with molybdenum disulfide is disclosed. This embodiment differs from Example 1 in that: in step S1, the amount of formamidine acetate used is 12g; the mass concentration of the hydrobromic acid solution is 45%; in step S1, after ultrasonic dispersion for 5 min, the mixture is heated to 55°C and stirred for 2.5 h; in step S2, the mass-to-volume ratio of formamidine halide to the mixed acid solution is 3g:100mL, the volume ratio of hydrohalic acid to hypophosphoric acid solution is 4:0.5, the heating temperature is 60°C, and the reaction time is 1.5 h; in step S3, the molar ratio of molybdate to sulfur source is 1:7, the hydrothermal reaction temperature is 180°C, and the hydrothermal reaction time is 28 h; in step S4, the mass concentration of formamidine lead halide perovskite in the saturated mixed acid solution is 1g / L, the heating temperature is 50°C, and the reaction time is 2.5 h.

[0125] The remaining components and preparation methods are the same as in Example 1.

[0126] Example 14

[0127] A method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. This embodiment differs from Example 1 in that the amount of formamidine acetate used in step S1 is 9g; hydroiodic acid solution is used instead of hydrobromic acid solution, and the mass concentration of the hydroiodic acid solution is 47%; in step S1, after ultrasonic dispersion for 15 min, the mixture is heated to 65°C and stirred for 1.5 h; in step S2, the mass-to-volume ratio of formamidine halide to the mixed acid solution is 10g:50mL, and the hydrohalic acid... The volume ratio of the sulfuric acid solution to the phosphoric acid solution was 4:0.8, the heating temperature was 70℃, and the reaction time was 1.3h. In step S3, potassium molybdate was used to replace sodium molybdate, thiourea was used to replace thioacetamide, the molar ratio of molybdate to sulfur source was 1:8, the hydrothermal reaction temperature was 220℃, and the hydrothermal reaction time was 20h. In step S4, the mass concentration of formamidinium lead halide perovskite in the saturated mixed acid solution was 4g / L, the heating temperature was 80℃, and the reaction time was 1.5h.

[0128] The remaining components and preparation methods are the same as in Example 1.

[0129] Example 15

[0130] Application of a lead-halide-rich perovskite-bonded molybdenum disulfide photocatalytic material in the photocatalytic decomposition of hydrogen halides to produce hydrogen. Specifically, a method for photocatalytic decomposition of hydrogen halides to produce hydrogen utilizes any one of the lead-halide-rich perovskite-bonded molybdenum disulfide photocatalytic materials from Examples 1 to 14, comprising the following steps: dispersing the photocatalytic material in a saturated mixed acid solution, removing air by vacuum, and using a xenon lamp as a light source to photocatalytically decompose the hydrogen halides in the saturated mixed acid solution to produce hydrogen gas.

[0131] In this embodiment, the mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is 3 mg: 1 mL; the xenon lamp has a power of 300 W and is equipped with an AM 1.5 filter and a filter with 420 < λ < 780 nm.

[0132] Example 16

[0133] A method for photocatalytic decomposition of hydrogen halides to produce hydrogen, the difference between this embodiment and Example 15 is that the mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is 1 mg: 1 mL; and the power of the xenon lamp is 250 W.

[0134] Example 17

[0135] A method for photocatalytic decomposition of hydrogen halides to produce hydrogen, the difference between this embodiment and Example 15 is that the mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is 5 mg: 1 mL; and the power of the xenon lamp is 350 W.

[0136] Comparative Example 1

[0137] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. The difference between this comparative example and Example 1 is that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 20 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is denoted as FAPbBr3-1.0, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is denoted as 20%MoS2 / FAPbBr3-1.0.

[0138] Comparative Example 2

[0139] A method for synthesizing a lead halide perovskite-bonded molybdenum disulfide photocatalytic material is disclosed. The difference between this comparative example and Example 1 is that the amounts of formamidine bromide (FABr) and lead bromide (PbBr2) added are 24 mmol and 20 mmol, respectively. The synthesized formamidine lead halide perovskite is designated FAPbBr3-1.2, and the lead halide perovskite-bonded molybdenum disulfide photocatalytic material obtained after loading MoS2 is designated 20%MoS2 / FAPbBr3-1.2.

[0140] Comparative Example 3

[0141] A method for synthesizing a Pt-supported photocatalytic material, which differs from Example 1 in that it does not use a strong lead-sulfur bond to support the co-catalyst molybdenum disulfide, but instead uses a Pt-supported catalyst. The method specifically includes the following steps:

[0142] S1. Synthesis of formamidine halide: 10g of formamidine acetate was added to 18mL of hydrobromic acid solution (48wt% aqueous solution) and ultrasonically dispersed for 10min. The mixture was then heated to 60℃ and stirred for 2h. The product was then placed in a rotary evaporator at 60℃ to remove the solvent and obtain a crude product. The crude product was then recrystallized three times with ethanol and diethyl ether solution, washed three times with diethyl ether, and finally dried in a vacuum oven at 50℃ for 6h to obtain a white powder product, namely formamidine bromide (FABr).

[0143] S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: 18 mmol of formamidine bromide and 20 mmol of lead bromide (PbBr2) were added to a mixed acid solution consisting of 40 mL of hydrobromic acid and 10 mL of hypophosphoric acid solution. The mixture was heated to 80 °C and stirred for 1 h to reach dynamic equilibrium. After natural cooling to room temperature, the mixture was centrifuged to separate the solid and liquid phases. The precipitate obtained after centrifugation was placed in a vacuum oven at 60 °C and dried for 12 h to obtain an orange powder product, which is formamidine lead halide perovskite (denoted as FAPbBr3-0.9). A saturated solution of formamidine lead halide perovskite in mixed acid was also obtained, which is the saturated mixed acid solution.

[0144] S3. Synthesis of photocatalytic material: 100 mg of formamidinium lead halide perovskite (FAPbBr3-0.9) synthesized in step S2 was added to 50 mL of saturated mixed acid solution obtained in step S2 and stirred for 30 min to obtain a uniform dispersion. Then, 5 mg of H2PtCl6·6H2O was added to the dispersion and stirred for 30 min. Subsequently, the mixture was irradiated with a 300 W xenon lamp (visible spectrum) for 2 h for photoreduction. The precipitate was collected by centrifugation and dried in a vacuum oven at 60 °C for 12 h to obtain a dark orange powder product, FAPbBr3-0.9 / Pt photocatalytic material (denoted as FAPbBr3-0.9 / Pt).

[0145] Comparative Example 4

[0146] A method for synthesizing a photocatalytic material, which differs from Example 1 in that only steps S1 and S2 are performed to obtain formamidinium lead halide perovskite, specifically including the following steps:

[0147] S1. Synthesis of formamidine halide: 10g of formamidine acetate was added to 18mL of hydrobromic acid solution (48wt% aqueous solution) and ultrasonically dispersed for 10min. The mixture was then heated to 60℃ and stirred for 2h. The product was then placed in a rotary evaporator at 60℃ to remove the solvent and obtain a crude product. The crude product was then recrystallized three times with ethanol and diethyl ether solution, washed three times with diethyl ether, and finally dried in a vacuum oven at 50℃ for 6h to obtain a white powder product, namely formamidine bromide (FABr).

[0148] S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: 18 mmol of formamidine bromide and 20 mmol of lead bromide (PbBr2) were added to a mixed acid solution consisting of 40 mL of hydrobromic acid and 10 mL of hypophosphoric acid solution. The mixture was heated to 80 °C and stirred for 1 h to reach dynamic equilibrium. After natural cooling to room temperature, the mixture was centrifuged to separate the solid and liquid phases. The precipitate obtained after centrifugation was placed in a vacuum oven at 60 °C and dried for 12 h to obtain an orange powder product, which is formamidine lead halide perovskite (denoted as FAPbBr3-0.9). A saturated solution of formamidine lead halide perovskite in mixed acid was also obtained, which is the saturated mixed acid solution.

[0149] Structural morphology characterization

[0150] (I) Crystal structure characterization by X-ray powder diffraction

[0151] (1) The formamidinium lead halide perovskites prepared in Examples 1-5 were subjected to X-ray powder diffraction tests, and the test results are as follows: Figure 1 As shown. By Figure 1 As can be seen from the X-ray diffraction pattern, the FAPbBr3-0.9 synthesized with a lead-rich layer at a FABr:PbBr2 (molar ratio of formamidinium bromide to lead bromide) ratio of 0.9:1 exhibits better crystallinity than the FAPbBr3-0.9 synthesized at a FABr:PbBr2 ratio of 1:1 without a lead-rich layer. 3- 1.0 It has a consistent crystal structure, has not undergone a phase transition, and also has good crystallinity.

[0152] (2) X-ray powder diffraction tests were performed on the FAPbBr3-0.9, MoS2, and 20% MoS2 / FAPbBr3-0.9 prepared in Example 1, respectively. The test results are as follows: Figure 5 As shown. By Figure 5 As can be seen from the X-ray powder diffraction pattern, the 20% MoS2 / FAPbBr3-0.9 generated after loading MoS2 did not show any peak shift and maintained the original crystal form.

[0153] (II) Characterization by UV-Vis absorption spectroscopy

[0154] (1) The formamidinium lead halide perovskites prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to ultraviolet-visible absorption spectroscopy analysis. The test results are as follows: Figure 2 As shown. By Figure 2It can be seen that the formamidinium lead halide perovskites prepared in Examples 1-3 and Comparative Examples 1-2 all exhibit an absorption edge at 570 nm, and the absorption edge of each material remains unchanged. When the molar ratio of formamidinium bromide to lead bromide is 0.8:1, 0.9:1, and 1:1, the formamidinium lead halide perovskites show stronger absorption intensity in the visible and near-ultraviolet regions; while the absorption intensity is lower when the molar ratio of formamidinium bromide to lead bromide is 0.7:1 and 1.2:1. This is because an appropriate amount of lead bromide does not affect the light absorption of the perovskite; however, excessive lead bromide forms an excessively thick lead-rich layer on the perovskite surface, which reduces the light absorption of the material. In addition, when formamidinium bromide is excessive, the intrinsic absorption of the synthesized formamidinium lead halide perovskite is poor.

[0155] (2) The FAPbBr3-0.9, MoS2, and 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 were subjected to UV-Vis absorption spectroscopy analysis, and the test results are as follows: Figure 6 As shown. By Figure 6 It can be seen that the absorption edge of the 20% MoS2 / FAPbBr3-0.9 formed after loading MoS2 on FAPbBr3-0.9 remains unchanged compared to the original FAPbBr3-0.9, while effectively improving the light absorption of the photocatalytic material 20% MoS2 / FAPbBr3-0.9 in the near-infrared and visible light regions. Furthermore, visually, the color of FAPbBr3-0.9 changes from orange to brown after loading MoS2.

[0156] (III) Morphological characterization by scanning electron microscopy

[0157] The FAPbBr3-0.9 prepared in Example 1 was characterized by scanning electron microscopy, and the test results are as follows: Figure 7 As shown. The 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 was characterized by scanning electron microscopy, and the test results are as follows. Figure 8 As shown. By Figure 7 and Figure 8 It can be seen that FAPbBr3-0.9 exhibits a near-spherical, pseudo-dodecahedral shape with a particle size of 40–60 μm. The particle size of the 20% MoS2 / FAPbBr3-0.9 formed after MoS2 loading is somewhat reduced, but the morphology remains consistent. Furthermore, from… Figure 8 As can be seen, MoS2 is uniformly distributed on FAPbBr3-0.9, forming a uniform and stable 20% MoS2 / FAPbBr3-0.9.

[0158] (iv) Characterization of elemental distribution by energy scattering using scanning electron microscopy

[0159] (1) The formamidinium lead halide perovskite prepared in Example 1 was subjected to scanning electron microscopy energy scattering elemental distribution analysis. The test results are as follows: Figure 4 As shown. By Figure 4 It can be seen that the carbon, lead, and bromine elements in the prepared formamidinium lead halide perovskite are evenly distributed.

[0160] (2) The 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 was subjected to scanning electron microscopy energy scattering elemental distribution analysis. The test results are as follows: Figure 9 As shown. By Figure 9 It can be seen that carbon, lead, bromine, molybdenum and sulfur are all distributed in the prepared 20% MoS2 / FAPbBr3-0.9, indicating that MoS2 is loaded on FAPbBr3 through lead-sulfur bonds.

[0161] (V) Infrared Spectroscopy Analysis

[0162] The FAPbBr3-0.9, MoS2, and 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 were subjected to infrared spectroscopy. The test results are as follows. Figure 10 As shown. By Figure 10 As can be seen from the infrared spectrum, 20% MoS2 / FAPbBr3-0.9 exhibits three peaks near 476 nm, 990 nm, and 1180 nm, corresponding to the vibration of the Pb-S bond. This indicates that MoS2 is bonded to FAPbBr3-0.9 through the Pb-S bond. At the same time, the vibrations of the Mo-S and SS bonds are also observed, indicating that MoS2 is chemically loaded onto the surface of FAPbBr3-0.9, thus exhibiting excellent structural stability.

[0163] (vi) Raman spectroscopy analysis

[0164] Raman spectroscopy was performed on the FAPbBr3-0.9, MoS2, and 20% MoS2 / FAPbBr3-0.9 prepared in Example 1. The test results are as follows. Figure 11 As shown. By Figure 11 The Raman spectrum shows three peaks around 246 nm, 430 nm, and 720 nm for the Pb-S bond vibration of 20% MoS2 / FAPbBr3-0.9, indicating that MoS2 is bonded to FAPbBr3-0.9 through Pb-S bonds. Therefore, the prepared photocatalytic material has excellent structural stability.

[0165] (vii) X-ray photoelectron spectroscopy analysis

[0166] (1) The FAPbBr3-0.9 and 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 were subjected to X-ray photoelectron spectroscopy for bromine element detection and analysis. The test results are as follows: Figure 12 As shown. By Figure 12It can be seen that the bromine element in X-ray photoelectron spectroscopy proves that after FAPbBr3-0.9 is loaded with MoS2, electrons flow from FAPbBr3-0.9 to MoS2, causing the whole to move towards a higher binding energy.

[0167] (2) The molybdenum element in MoS2 and 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 was analyzed by X-ray photoelectron spectroscopy. The test results are as follows: Figure 13 As shown. By Figure 13 It can be seen that the molybdenum element in the X-ray photoelectron spectroscopy indicates that MoS2 gains electrons after being loaded onto FAPbBr3-0.9, and the whole structure shifts to a lower binding energy.

[0168] (viii) Electromotive force analysis

[0169] The electromotive force performance of the formamidinium lead halide perovskites prepared in Examples 1-3 and Comparative Examples 1-2, and the molybdenum disulfide prepared in Example 1, were tested. The test results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the positive potential of the formamidinium lead halide perovskite prepared in Examples 1 to 3 is improved compared with that of Comparative Example 1. This is due to the presence of more positive lead ions on the material surface. Therefore, it is shown that when the molar ratio of formamidinium bromide to lead bromide in Examples 1 to 3 is 0.9:1, 0.7:1, and 0.8:1, the material surface has abundant lead sites compared with the molar ratio of formamidinium bromide to lead bromide of 1:1 in Comparative Example 1.

[0170] Furthermore, the formamidinium lead halide perovskites prepared in Examples 1-3 exhibit a significantly higher positive potential compared to Comparative Example 2, and all are positively charged, while MoS2 shows a stronger negative charge. That is, the potential decrease in Comparative Example 2 is due to the presence of more bromide ions in the material. Therefore, when the molar ratio of formamidinium bromide to lead bromide in Comparative Example 2 is 1.2:1, it leads to a decrease in the potential of the prepared formamidinium lead halide perovskite. Simultaneously, MoS2 exhibits a stronger negative charge, indicating that formamidinium lead halide perovskites can electrostatically self-assemble with MoS2 to form a composite material.

[0171] Performance testing

[0172] (I) Determination of photocatalytic hydrogen production activity

[0173] Photocatalytic decomposition of HBr to produce hydrogen was tested. The photocatalytic reaction was carried out in a glass reaction cell with a quartz cover, which was connected to a closed gas circulation and vacuum system. A circulating cooling water system (20°C) was connected below to maintain a constant temperature during the reaction. The illumination source at the top was a 300W xenon lamp simulating sunlight (AM1.5, 420 < λ < 780 nm, 100 mW / cm²). 2Add 50 mg of photocatalytic material to 50 mL of the corresponding saturated mixed acid reaction solution, stir and evacuate for 30 min to ensure that the air in the reactor is completely removed. Analyze the separated gas by gas chromatography. Set the system to automatically sample once every 30 min of illumination. In the cyclic test, every 5 h is considered a cycle. The system is evacuated again to start the test.

[0174] The photocatalytic hydrogen production activity of each 20% MoS2 / FAPbBr3 prepared in Examples 1-3 and Comparative Examples 1-2 was tested. The test results are as follows: Figure 14 As shown. By Figure 14 It can be seen that, under the current test conditions, the photocatalytic material 20%MoS2 / FAPbBr3 prepared in Example 1 has the best hydrogen production activity, which is 14000 μmol / g / h.

[0175] In addition, the photocatalytic hydrogen production cycle stability test was conducted using the 20% MoS2 / FAPbBr3 photocatalytic material prepared in Example 1. The test results of its photocatalytic hydrogen production cycle stability are as follows: Figure 15 As shown. From Figure 15 It can be seen that the photocatalytic stability of the 20% MoS2 / FAPbBr3 photocatalyst material prepared in Example 1 is good.

[0176] In addition, the photocatalytic hydrogen production activity of the 20% MoS2 / FAPbBr3-0.9 and MoS2 samples prepared in Example 1, the FAPbBr3-0.9 / Pt sample prepared in Comparative Example 3, and the FAPbBr3-0.9 sample prepared in Comparative Example 4 were compared and tested. The test results are as follows: Figure 16 As shown. By Figure 16 It can be seen that the 20% MoS2 / FAPbBr3-0.9 prepared in Example 1 exhibits the best hydrogen production activity. Therefore, the lead-rich halide perovskite-bonded molybdenum disulfide photocatalyst prepared in this invention has better hydrogen production activity than the Pt-loaded photocatalyst prepared in Comparative Example 3.

[0177] In addition, the photocatalytic hydrogen production activity of each MoS2 / FAPbBr3-0.9 sample prepared in Examples 1 and 6-11 was tested and compared. The test results are as follows: Figure 17 As shown. By Figure 17 It can be seen that the photocatalytic material 20%MoS2 / FAPbBr3-0.9 prepared in Example 1 has the best hydrogen production performance. It is evident that the photocatalytic material prepared when the mass ratio of formamidinium lead halide perovskite to molybdenum disulfide is 5:1 exhibits the best hydrogen production performance.

[0178] (II) Photocatalytic stability test

[0179] The stability of the 20% MoS2 / FAPbBr3-0.9 sample prepared in Example 1 was tested by X-ray powder diffraction before and after photocatalytic hydrogen production. The test results are as follows: Figure 18 As shown. By Figure 18 It can be seen that the structure of the photocatalytic material prepared by the present invention remains unchanged after catalytic hydrogen production compared to before catalytic hydrogen production, proving that the lead halide perovskite-bonded molybdenum disulfide photocatalytic material prepared by the present invention not only has strong surface interface effects, but also has good photocatalytic stability.

[0180] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A photocatalytic material composed of lead-rich halide perovskite and molybdenum disulfide, characterized in that, The method for synthesizing the lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material includes the following steps: S1. Synthesis of formamidine halide: Formamidine acetate is added to a hydrohalic acid solution and ultrasonically dispersed, then heated and stirred to react. The solvent is then removed, washed, and dried to obtain formamidine halide. The hydrohalic acid solution includes one or a combination of two of hydrobromic acid or hydroiodic acid. S2. Preparation of formamidine lead halide perovskite and saturated mixed acid solution: Add excess formamidine halide and lead halide to a mixed acid solution composed of hydrohalic acid and hypophosphoric acid solution, heat and stir at 60℃~80℃ for 1h~1.5h, cool, and centrifuge to separate solid and liquid to obtain formamidine lead halide perovskite and saturated mixed acid solution. In step S2, the molar ratio of formamidine halide to lead halide is (0.7~0.95):1; the mass-to-volume ratio of formamidine halide to the mixed acid solution is (3~10) g: (50~100) mL; and the volume ratio of hydrohalic acid to hypophosphoric acid solution in the mixed solution is 4:(0.5~1). S3. Preparation of molybdenum disulfide: Molybdate and sulfur source are added to water and stirred to dissolve, followed by hydrothermal reaction. The mixture is then centrifuged, washed, and dried to obtain molybdenum disulfide. The molybdate is one or a combination of sodium molybdate or potassium molybdate. The sulfur source is one or a combination of thioacetamide or thiourea. S4. Synthesis of photocatalytic material: The formamidinium lead halide perovskite synthesized in step S2 and the molybdenum disulfide obtained in step S3 are added to the saturated mixed acid solution obtained in step S2 and heated and stirred at 50℃~80℃ for 1.5h~2.5h. After cooling, centrifugation and drying, FAPbX3 / MoS2 photocatalytic material is obtained, which is the lead halide perovskite bonded molybdenum disulfide photocatalytic material. In step S4, the mass ratio of formamidinium lead halide perovskite to molybdenum disulfide is (2.5~100):1; the mass concentration of formamidinium lead halide perovskite in the saturated mixed acid solution is 1g / L~4g / L.

2. The method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material according to claim 1, characterized in that, In step S1, the mass-to-volume ratio of formamidine acetate to hydrohalic acid solution is 1 g:(1.5~2) mL; and / or The mass concentration of the hydrohalic acid solution is 45%~48%.

3. The method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material as described in claim 2, characterized in that, In step S1, the ultrasonic dispersion time is 5 min to 15 min, the heating temperature is 55℃ to 65℃, and the reaction time is 1.5 h to 2.5 h.

4. The method for synthesizing a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material as described in claim 2, characterized in that, In step S3 The molar ratio of molybdate to sulfur source is 1:(6~8); and / or The hydrothermal reaction temperature is 180℃~220℃, and the hydrothermal reaction time is 20h~28h.

5. The application of the lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material as described in claim 1 in the photocatalytic decomposition of hydrogen halides to produce hydrogen.

6. A method for photocatalytic decomposition of hydrogen halides to produce hydrogen, characterized in that, The method for photocatalytic decomposition of hydrogen halides to produce hydrogen using a lead-rich halide perovskite-bonded molybdenum disulfide photocatalytic material as described in claim 1 includes the following steps: dispersing the photocatalytic material in the saturated mixed acid solution, removing air by evacuation, and using a xenon lamp as a light source to photocatalytically decompose the hydrogen halides in the saturated mixed acid solution to produce hydrogen gas.

7. The method for photocatalytic decomposition of hydrogen halides to produce hydrogen as described in claim 6, characterized in that, The mass-to-volume ratio of the photocatalytic material to the saturated mixed acid solution is (1~5) mg: 1 mL; and / or The power of the xenon lamp is 250W~350W.

Images