A method for synthesizing nitrogen-doped carbon-encapsulated In₂O₃-CdSe hexagonal nanorod photocatalyst and its application in catalyzing benzylamine coupling reactions.

Abstract

The application discloses a synthesis method of nitrogen-doped carbon-coated In2O3-CdSe hexagonal nanorod, and comprises the following steps: dissolving indium nitrate tetrahydrate and terephthalic acid in an organic solvent, transferring the mixture into a reaction kettle after ultrasonic treatment for 10 minutes, heating the mixture for a period of time, centrifuging and collecting the product after the reaction is completed, cleaning the product with ethanol, and drying the product to obtain a MIL-68-In precursor with a hexagonal nanorod structure; dispersing the MIL-68-In precursor in an organic solvent containing dissolved cadmium acetate, transferring the mixture into a reaction kettle after ultrasonic treatment for 10 minutes, heating the mixture for a period of time, centrifuging and collecting the product after the reaction is completed, cleaning the product with ethanol for several times, drying the product, and using the product for further use, and then calcining the synthesized sample and selenium powder in a tube furnace to obtain In2O3-CdSe@N-C. The application synthesizes the In2O3-CdSe@N-C hexagonal nanorod photocatalyst through a solvothermal and calcination method, and the synthesized photocatalyst has higher photocatalytic activity than the MIL-68-In.

Description

Technical Field

[0001] This invention relates to nanomaterials, specifically to a method for synthesizing an In2O3-CdSe@NC hexagonal nanorod photocatalyst. Background Technology

[0002] In recent years, In₂O₃ has emerged as a semiconductor with a band gap of approximately 2.6-2.8 eV. It possesses unique optical, chemical, and electrical properties, making it suitable for a wide range of applications. In₂O₃ owes its value to the unique In₂O₃... 3+ d 10 In₂O₃ has garnered significant attention due to its electronic configuration, suitable conduction and valence band positions, and excellent thermal stability and strong fluorescence signal in the visible and ultraviolet regions. However, it also has drawbacks. For instance, its wide band gap in photocatalysis results in low light utilization efficiency in the visible region, and the tendency for photogenerated electrons and holes to recombine further limits its development in this field. One possible way to overcome these drawbacks is to combine In₂O₃ with functional semiconductor materials to prepare photocatalyst composites. CdSe, with its 1.74 eV band gap in the visible region and its ability to rapidly generate electron-hole pairs under visible light irradiation, is an effective material for constructing composite materials. Summary of the Invention

[0003] The purpose of this invention is to provide a simple method for synthesizing nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalysts to improve photocatalytic activity.

[0004] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0005] Specifically, this invention provides a method for synthesizing a nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalyst, comprising the following steps:

[0006] S1: Indium nitrate tetrahydrate and terephthalic acid were dissolved in an organic solvent, sonicated for 10 minutes, and then transferred to a reaction vessel and heated for a period of time. After the reaction was completed, the product was collected by centrifugation, washed with ethanol, and dried to obtain the MIL-68-In precursor with a hexagonal nanorod structure.

[0007] S2: The MIL-68-In precursor was dispersed in an organic solvent containing dissolved cadmium acetate, sonicated for 10 minutes, and then transferred to a reaction vessel and heated for a period of time. After the reaction was completed, the product was collected by centrifugation, washed several times with ethanol, and dried for further use. Subsequently, the synthesized sample was calcined with selenium powder in a tube furnace to obtain nitrogen-doped carbon-encapsulated In2O3-CdSe.

[0008] Furthermore, the volume of the organic solvent DMF is 10 mL.

[0009] Furthermore, in step S1, the heating temperature is 100°C and the reaction time is 4 hours.

[0010] Furthermore, in step S2, the heating temperature of the MIL-68-In precursor and cadmium acetate in the reactor is 160°C, and the reaction time is 2 hours; then the synthesized sample and selenium powder are calcined in a tube furnace at 450°C for 1 hour.

[0011] This invention also provides a method for synthesizing nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalysts using the above method.

[0012] This invention also provides the application of the above-mentioned nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorods as photocatalysts for the catalytic coupling reaction of benzylamine.

[0013] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0014] This invention discloses a simple method for synthesizing nitrogen-doped carbon-encapsulated In₂O₃-CdSe hexagonal nanorod photocatalysts. The method synthesizes In₂O₃-CdSe hexagonal nanorods coated with an N-doped C layer (NC). The In₂O₃-CdSe hexagonal nanorod catalyst exhibits good photocatalytic activity and cycling stability in the visible light region. The NC layer serves as a good acceptor of photogenerated electrons, and the large surface area of ​​the carbon material increases the exposure rate of active sites. The two-phase material forms a distinct heterogeneous interface, which promotes electron transfer, facilitates the effective spatial separation of photogenerated carriers, and extends the lifetime of photogenerated carriers. Attached Figure Description

[0015] Figure 1 This is the XRD pattern (a) of the MIL-68-In hexagonal nanorod precursor synthesized in the embodiments of the present invention;

[0016] SEM image (b) and corresponding elemental diagram (cf) of MIL-68-In hexagonal nanorods;

[0017] Figure 2 The images show the XRD pattern (a), Raman spectrum (b), TEM image (c), magnified TEM image (d), magnified view (e) of part (d) with SAED pattern inset, STEM image and EDX elemental map of In, O, Cd, Se, C and N (fk).

[0018] Figure 3 The images shown are: XRD pattern (a); SEM images (b, c); and corresponding elemental mapping (dh) of nitrogen-doped carbon-encapsulated In2O synthesized in the embodiments of the present invention.

[0019] Figure 4 These are the XRD patterns (a) and SEM images (b, c) of CdSe synthesized in this embodiment of the invention; and the corresponding elemental mapping diagram (dh).

[0020] Figure 5 These are photocurrent density diagrams of CdSe, nitrogen-doped carbon-encapsulated In2O3, and nitrogen-doped carbon-encapsulated CdSe-In2O3 synthesized in the embodiments of the present invention.

[0021] Figure 6 The yield of nitrogen-doped carbon-encapsulated In₂O₃-CdSe, CdSe, and nitrogen-doped carbon-encapsulated In₂O₃ as photocatalysts for the coupling reaction of phenylbenzylamine is... Detailed implementation method:

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example

[0024] Step 1: Synthesis of MIL-68-In precursor

[0025] Dissolve 0.078 g of indium nitrate tetrahydrate and 0.021 g of terephthalic acid in 10 mL of N,N-dimethylformamide solution. After sonication for 10 minutes, transfer the mixture to a 50 mL polytetrafluoroethylene high-pressure reactor and heat to 100 °C for 4 hours. Collect the product by centrifugation, wash it several times with anhydrous ethanol, and dry it in a drying oven to obtain the MIL-68-In precursor with a hexagonal nanorod structure.

[0026] Step 2: Synthesize nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalysts.

[0027] 0.01 g of MIL-68-In precursor and 0.006 g of cadmium acetate were dissolved in 3 mL of N,N-dimethylformamide solution. After sonication for 10 minutes, the mixture was transferred to a 25 mL reactor and heated in an oven at 160 °C for 2 h. After the reaction was completed, the product was collected by centrifugation, washed several times with ethanol, and dried for further use. Subsequently, the synthesized sample and selenium powder were calcined in a tube furnace at 450 °C for 1 h to obtain In2O3-CdSe@NC.

[0028] Figure 1The images show the XRD pattern (a), SEM image (b), and corresponding elemental diagram (cf) of the MIL-68-In hexagonal nanorod precursor synthesized in this embodiment of the invention. Figure 2 The images show: (a) X-ray powder diffraction pattern of nitrogen-doped carbon-encapsulated In2O3-CdSe synthesized in the embodiments of the present invention; (b) Raman spectrum; (c) TEM image; (d) magnified TEM image; (e) magnified view of part (d) with SAED pattern inset; (fk) STEM image and EDX elemental map of In, O, Cd, Se, C, and N; Figure 3 The images shown are: XRD pattern (a); SEM images (b, c); and corresponding elemental mapping (dh) of nitrogen-doped carbon-encapsulated In2O3 synthesized in the embodiments of the present invention. Figure 4 The images shown are: XRD pattern (a); SEM images (b, c); and corresponding elemental diagram (dh) of CdSe synthesized in the embodiments of the present invention. Figure 5 This is a photocurrent density diagram of CdSe, In2O3, and CdSe-In2O3 synthesized in the embodiments of the present invention. Figure 6 The yield of the phenylbenzylamine coupling reaction with In2O3-CdSe, CdSe, and In2O3 as photocatalysts is from... Figure 6 As can be seen, the nitrogen-doped carbon-encapsulated In2O3-CdSe photocatalyst exhibits higher photocatalytic activity.

[0029] This invention discloses a simple method for synthesizing nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalysts. The method synthesizes In2O3-CdSe hexagonal nanorods composed of N-doped C layers. The In2O3-CdSe catalyst exhibits good photocatalytic activity and cycling stability in the visible light region. The N-C layer serves as a good acceptor of photogenerated electrons, and the large surface area of ​​the carbon material increases the exposure rate of active sites. The two-phase material forms a distinct heterogeneous interface, which promotes electron transfer, facilitates the effective spatial separation of photogenerated carriers, and extends the lifetime of photogenerated carriers.

Claims

1. The application of a nitrogen-doped carbon-encapsulated In₂O₃-CdSe hexagonal nanorod photocatalyst in the photocatalytic benzylamine coupling reaction, characterized in that, The synthesis method of this photocatalyst includes the following steps: S1: Indium nitrate tetrahydrate and terephthalic acid were dissolved in the organic solvent N,N-dimethylformamide, sonicated for a period of time, and then transferred to a reaction vessel and heated for a period of time. After the reaction was completed, the product was collected by centrifugation, washed with ethanol, and dried to obtain the MIL-68-In precursor with a hexagonal nanorod structure. S2: The MIL-68-In precursor was dispersed in N,N-dimethylformamide, an organic solvent containing cadmium acetate. After sonication for 10 minutes, the mixture was transferred to a reaction vessel and heated for a period of time. After the reaction was completed, the product was collected by centrifugation, washed several times with ethanol, and dried for further use. Subsequently, the synthesized sample was calcined with selenium powder in a tube furnace to obtain nitrogen-doped carbon-encapsulated In2O3-CdSe hexagonal nanorod photocatalyst.

2. The application according to claim 1, characterized in that, In step S1, the volume of the organic solvent N,N-dimethylformamide is 10 mL.

3. The application according to claim 1, characterized in that, In step S1, the heating temperature is 100 ℃ and the reaction time is 4 h.

4. The application according to claim 1, characterized in that, In step S2, the MIL-68-In precursor and cadmium acetate are heated to 160 °C in a reactor for 2 h; then the synthesized sample and selenium powder are calcined in a tube furnace at 450 °C for 1 h.

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