Preparation method of two-dimensional nano black phosphorus-based cadmium sulfide-doped heterojunction material
By preparing two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction materials, the stability and large-scale preparation problems of black phosphorus materials in the field of photocatalysis were solved, and high-efficiency photocatalytic performance was achieved, especially in the improvement of photogenerated carrier separation and migration.
Patent Information
- Application Number
- CN202510769537.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-10
- Publication Date
- 2025-09-19
AI Technical Summary
Black phosphorus materials have problems with stability and large-scale preparation in the field of photocatalysis, and heterogeneous structure construction helps to optimize their performance, but existing technologies have failed to effectively solve these problems.
By preparing two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction materials, using red phosphorus pretreatment, solvent thermal method and precipitation method, two-dimensional nano black phosphorus/red phosphorus composite materials and black phosphorus/red phosphorus doped cadmium sulfide heterojunctions were constructed to form rich charge transfer channels.
The transmission efficiency of photogenerated carriers is improved, the photocatalytic activity is enhanced, and the ability to efficiently decompose water to produce hydrogen is achieved.
Smart Images
Figure CN120662344A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of nanomaterial photocatalysis, and in particular to a method for preparing a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material. Background Art
[0002] Black phosphorus has received considerable attention in recent years in photocatalytic research. Black phosphorus crystals consist of a multilayered lamellar structure, with layers bonded by van der Waals forces, and can therefore be peeled off to form a two-dimensional structure. Black phosphorus has the following advantages: (1) adjustable band gap, with the band gap varying between 0.3 and 1.5 eV; (2) wide light absorption range, resulting in high utilization of solar energy; (3) high electron mobility (~1000 cm 2 ﹒ V -1 ﹒ s -1 ), which facilitates the separation of electron-hole pairs, accelerates the redox reaction process, and thus improves the photocatalytic performance; (4) The large specific surface area is conducive to the adsorption and reaction of reactants on the surface of the material. Based on the above characteristics, black phosphorus is a material with great potential and has been widely studied and applied in the fields of photocatalysis and environmental governance.
[0003] However, despite the huge application prospects of black phosphorus materials, their stability, biocompatibility and large-scale preparation remain challenges in current research. To overcome these problems, researchers have explored different synthesis methods, surface modification techniques and composite material designs, and found that the performance of black phosphorus can be further optimized by forming heterojunctions or composites with other materials. This is mainly reflected in the following two points: (1) The construction of heterojunction structures is conducive to broadening the spectral absorption range, enhancing light absorption capacity, and increasing the density of photogenerated carriers; (2) The construction of heterojunctions is conducive to the separation and migration of photogenerated carriers, accelerating the separation of electron-hole pairs, and thus improving the stability of black phosphorus materials. Summary of the Invention
[0004] To address the aforementioned technical issues in the prior art, the present invention provides a method for preparing a two-dimensional nano-black phosphorus-based doped cadmium sulfide heterojunction material. This material has efficient photocatalytic properties and can be used to decompose water to produce hydrogen. The technical solution is as follows:
[0005] A method for preparing a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material, characterized in that the method comprises:
[0006] S1. Pretreatment of red phosphorus:
[0007] Adding red phosphorus and deionized water into a hydrothermal reactor, heating the reactor in a constant temperature drying oven, removing the supernatant by centrifugation, spreading the solid on a watch glass, and drying the solid in a vacuum drying oven to obtain treated red phosphorus;
[0008] S2. Preparation of two-dimensional nano black phosphorus / red phosphorus composite materials using a solvothermal method:
[0009] Add diethylenetriamine and the red phosphorus treated in step S1 to a hydrothermal reaction kettle, heat the reaction kettle in a constant temperature drying oven, cool the reaction kettle, remove the reaction kettle from the oven, wash the reaction kettle with deionized water, and then wash the reaction kettle with anhydrous ethanol. Spread the resulting solid on a watch glass, and dry the solid in a vacuum drying oven to obtain a two-dimensional nano black scale / red phosphorus composite material.
[0010] S3. Preparation of black phosphorus / red phosphorus doped cadmium sulfide heterojunction by precipitation method:
[0011] Cadmium sulfate is dissolved in deionized water and stirred, and then the two-dimensional nano black phosphorus / red phosphorus composite material prepared in step S2 is added while stirring; after sufficient stirring, thiourea is added to the solution and stirring is continued; the stirred mixed solution is then transferred to a high-pressure reactor and placed in a constant temperature drying oven for heating. The prepared sample is washed with deionized water and anhydrous ethanol, respectively, and finally dried in a vacuum drying oven to obtain a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material.
[0012] The mass ratio of red phosphorus to deionized water in step S1 is (1-3): (20-30).
[0013] In step S1, the temperature of the constant temperature drying oven is 150-250° C., and the heating time is 10-15 hours.
[0014] In step S1, the temperature of the vacuum drying oven is 50-80° C., and the drying time is 5-10 hours.
[0015] The mass volume ratio of the red phosphorus and diethylenetriamine after treatment in step S2 is (8-12) mg: (0.8-1.2) mL.
[0016] In step S2, the temperature of the constant temperature drying oven is 180-220° C., the heating time is 10-15 hours, and the oven is cooled naturally after heating.
[0017] In step S2, the product is washed with deionized water for no less than 3 times, and washed with anhydrous ethanol for no less than 3 times. The temperature of the vacuum drying oven is 40-80° C., and the drying time is 5-10 hours.
[0018] In step S3, the amount of the two-dimensional nano black phosphorus / red phosphorus composite material added is 5-20% of the mass of the cadmium sulfate, and the stirring time is not less than 1 hour; the mass of the added thiourea is 1-1.5 times the mass of the cadmium sulfate, and the stirring time after adding thiourea is not less than 2 hours.
[0019] In step S3, the temperature of the constant temperature drying oven is 160-220° C., the heating time is 10-15 hours, the number of washing times with deionized water is not less than 3 times, and the number of washing times with anhydrous ethanol is not less than 3 times.
[0020] In step S3, the temperature of the vacuum drying oven is 40-80° C., and the drying time is 10-15 hours.
[0021] The two-dimensional nano-black phosphorus-doped cadmium sulfide heterojunction material prepared by the above method has efficient photocatalytic ability and can be used to decompose water to produce hydrogen. When used, the amount of the two-dimensional nano-black phosphorus-doped cadmium sulfide heterojunction material is 8-10%.
[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:
[0023] The above scheme successfully prepared a two-dimensional nanoscale black phosphorus-doped cadmium sulfide heterojunction material through a simple and effective method. The prepared photocatalyst has the following advantages: the two-dimensional nanoscale black phosphorus-doped cadmium sulfide heterojunction material has more abundant charge transfer channels, and the larger contact area shortens the transmission time and distance of photogenerated carriers. These advantages significantly improve charge mobility, thereby enhancing the efficiency of photocatalytic activity and achieving efficient hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0025] Figure 1 This is a TEM image of a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material provided by an embodiment of the present invention;
[0026] Figure 2 This is an SEM image of a two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material prepared in an embodiment of the present invention;
[0027] Figure 3 This is an XRD image of a two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material prepared in an embodiment of the present invention;
[0028] Figure 4 This is an analysis of the photocatalytic hydrogen production activity of a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material prepared in an embodiment of the present invention. DETAILED DESCRIPTION
[0029] The technical solution of the present invention is described below in conjunction with the accompanying drawings.
[0030] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.
[0031] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.
[0032] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.
[0033] The present invention provides a method for preparing a two-dimensional nano-black phosphorus-based doped cadmium sulfide heterojunction material. The method may include the following steps:
[0034] S1. Pretreatment of red phosphorus:
[0035] Adding red phosphorus and deionized water into a hydrothermal reactor, heating the reactor in a constant temperature drying oven, removing the supernatant by centrifugation, spreading the solid on a watch glass, and drying the solid in a vacuum drying oven to obtain treated red phosphorus;
[0036] S2. Preparation of two-dimensional nano black phosphorus / red phosphorus composite materials using a solvothermal method:
[0037] Add diethylenetriamine and the red phosphorus treated in step S1 to a hydrothermal reaction kettle, heat the reaction kettle in a constant temperature drying oven, cool the reaction kettle, remove the reaction kettle from the oven, wash the reaction kettle with deionized water, and then wash the reaction kettle with anhydrous ethanol. Spread the resulting solid on a watch glass, and dry the solid in a vacuum drying oven to obtain a two-dimensional nano black scale / red phosphorus composite material.
[0038] S3. Preparation of black phosphorus / red phosphorus doped cadmium sulfide heterojunction by precipitation method:
[0039] Cadmium sulfate is dissolved in deionized water and stirred, and then the two-dimensional nano black phosphorus / red phosphorus composite material prepared in step S2 is added while stirring; after sufficient stirring, thiourea is added to the solution and stirring is continued; the stirred mixed solution is then transferred to a high-pressure reactor and placed in a constant temperature drying oven for heating. The prepared sample is washed with deionized water and anhydrous ethanol, respectively, and finally dried in a vacuum drying oven to obtain a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material.
[0040] The following describes this with reference to specific embodiments.
[0041] Example 1
[0042] This embodiment provides a method for preparing a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material, which specifically includes the following steps:
[0043] (1) In a hydrothermal reactor, add 1.5 g of red phosphorus and 30 mL of deionized water, place in a constant temperature drying oven at 200 °C and heat for 12 h. Centrifuge to remove the supernatant, spread the solid on a watch glass, and place in a vacuum drying oven at 60 °C and dry for 8 h.
[0044] (2) Add 300 mg of treated red phosphorus and 30 mL of diethylenetriamine to a hydrothermal reactor and place in a 120°C constant temperature drying oven for 12 h. After cooling, remove the product and wash it three times with deionized water and then three times with anhydrous ethanol. Spread the resulting solid on a watch glass and dry it in a 60°C vacuum drying oven for 12 h.
[0045] (3) Dissolve 0.4 g of cadmium sulfate (CdSO4) in 30 mL of deionized water and stir for 1 hour. Then, add 5, 10, 15, and 20 wt% of the two-dimensional nano black phosphorus / red phosphorus composite material prepared in step (2) to the above solution while stirring. After stirring for 1 hour, add 0.5 g of thiourea to the solution, and then stir the mixed solution for 2 hours. Then transfer the above solution to a 50 mL high-pressure reactor, place it in a constant temperature drying oven at 200°C and heat it for 12 hours. The prepared samples are washed with deionized water and ethanol three times each, and then dried in a vacuum drying oven at 60°C for 12 hours for use.
[0046] The following tests were performed on the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material prepared in Example 1:
[0047] 1. TEM characterization of two-dimensional nano-black phosphorus-based doped cadmium sulfide heterojunction materials
[0048] like Figure 1 As shown, the particles are cadmium sulfide, while the light-colored flakes are two-dimensional nano-black phosphorus / red phosphorus. The two-dimensional nano-black phosphorus / red phosphorus is well-combined and in close contact with the cadmium sulfide. To confirm the different compositions of black phosphorus / red phosphorus and cadmium sulfide in the nanocomposite, selected areas were analyzed using HRTEM: different lattice fringes with lattice spacings of 0.35 and 0.36 nm correspond to the (002) crystal plane of cadmium sulfide and the (021) crystal plane of black phosphorus, respectively. The results show that the two-dimensional nano-black phosphorus / red phosphorus is successfully composited with the cadmium sulfide surface.
[0049] 2. SEM characterization of two-dimensional nano-black phosphorus-based doped cadmium sulfide heterojunction materials
[0050] Figure 2This SEM image shows a 10wt% 2D black phosphorus nanoparticle-doped cadmium sulfide heterojunction. The results show that the 2D black phosphorus / red phosphorus nanoparticles have a typical thin-layer structure and are tightly integrated with the granular cadmium sulfide, consistent with the TEM results. The EDS elemental distribution of the 10wt% 2D black phosphorus / red phosphorus / cadmium sulfide nanostructure indicates that the material is composed of cadmium, sulfur, and phosphorus.
[0051] 3. XRD characterization of two-dimensional nano-black phosphorus-based doped cadmium sulfide heterojunction materials
[0052] Figure 3 The XRD patterns of 2D nano-black phosphorus / red phosphorus doped with cadmium sulfide at different ratios (5-20 wt%) are shown. The XRD pattern of cadmium sulfide has six distinct diffraction peaks. In addition, diffraction peaks of 2D nano-black phosphorus / red phosphorus are also observed in 2D nano-black phosphorus / red phosphorus / cadmium sulfide.
[0053] 4. Analysis of the photocatalytic hydrogen production activity of two-dimensional nano-black phosphorus-doped cadmium sulfide heterojunction materials
[0054] The photocatalytic hydrogen production performance of the prepared material was investigated, and methanol was used as a sacrificial agent in the photocatalytic hydrogen production reaction. Figure 4 As shown in the figure, under UV light irradiation, the hydrogen production rate is positively correlated with the increase in the ratio of two-dimensional nano-black phosphorus to red phosphorus. However, when the ratio exceeds 10%, the hydrogen production activity decreases significantly. Therefore, the ratio of two-dimensional nano-black phosphorus to red phosphorus is controlled at 10%.
[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.
Claims
1. A method for preparing a two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material, characterized in that: The method comprises: S1. Pretreatment of red phosphorus: Adding red phosphorus and deionized water into a hydrothermal reactor, heating the reactor in a constant temperature drying oven, removing the supernatant by centrifugation, spreading the solid on a watch glass, and drying the solid in a vacuum drying oven to obtain treated red phosphorus; S2. Preparation of two-dimensional nano black phosphorus / red phosphorus composite materials using a solvothermal method: Add diethylenetriamine and the red phosphorus treated in step S1 to a hydrothermal reaction kettle, heat the reaction kettle in a constant temperature drying oven, cool the reaction kettle, remove the reaction kettle from the oven, wash the reaction kettle with deionized water, and then wash the reaction kettle with anhydrous ethanol. Spread the resulting solid on a watch glass, and dry the solid in a vacuum drying oven to obtain a two-dimensional nano black scale / red phosphorus composite material. S3. Preparation of black phosphorus / red phosphorus doped cadmium sulfide heterojunction by precipitation method: Cadmium sulfate is dissolved in deionized water and stirred, and then the two-dimensional nano black phosphorus / red phosphorus composite material prepared in step S2 is added while stirring; after sufficient stirring, thiourea is added to the solution and stirring is continued; the stirred mixed solution is then transferred to a high-pressure reactor and placed in a constant temperature drying oven for heating. The prepared sample is washed with deionized water and anhydrous ethanol, respectively, and finally dried in a vacuum drying oven to obtain a two-dimensional nano black phosphorus-based doped cadmium sulfide heterojunction material.
2. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: The mass ratio of red phosphorus to deionized water in step S1 is (1-3): (20-30).
3. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S1, the temperature of the constant temperature drying oven is 150-250° C., and the heating time is 10-15 hours.
4. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S1, the temperature of the vacuum drying oven is 50-80° C., and the drying time is 5-10 hours.
5. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: The mass volume ratio of the red phosphorus and diethylenetriamine after treatment in step S2 is (8-12) mg: (0.8-1.2) mL.
6. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S2, the temperature of the constant temperature drying oven is 180-220° C., the heating time is 10-15 hours, and the oven is cooled naturally after heating.
7. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S2, the product is washed with deionized water for no less than 3 times, and washed with anhydrous ethanol for no less than 3 times. The temperature of the vacuum drying oven is 40-80° C., and the drying time is 5-10 hours.
8. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S3, the amount of the two-dimensional nano black phosphorus / red phosphorus composite material added is 5-20% of the mass of the cadmium sulfate, and the stirring time is not less than 1 hour; the mass of the added thiourea is 1-1.5 times the mass of the cadmium sulfate, and the stirring time after adding thiourea is not less than 2 hours.
9. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S3, the temperature of the constant temperature drying oven is 160-220° C., the heating time is 10-15 hours, the number of washing times with deionized water is not less than 3 times, and the number of washing times with anhydrous ethanol is not less than 3 times.
10. The method for preparing the two-dimensional nano black phosphorus-doped cadmium sulfide heterojunction material according to claim 1, characterized in that: In step S3, the temperature of the vacuum drying oven is 40-80° C., and the drying time is 10-15 hours.