A selenium nanowire material and a method for preparing the same

Abstract

The application discloses a preparation method of selenium nanowire material, which uses a silicon dioxide / silicon wafer as a substrate and selenium powder as a growth raw material, and adopts a vapor deposition method to deposit and grow the selenium nanowire; the deposition and growth container comprises a quartz tube, a raw material placing crucible and a substrate placing crucible are placed in the quartz tube, the raw material placing crucible is located at the gas inlet end of the quartz tube, and the substrate placing crucible is located at the gas outlet end of the quartz tube; the silicon dioxide surface of the substrate faces downward and is placed on the substrate placing crucible, and the selenium powder is placed in the raw material placing crucible; and the deposition and growth of the selenium nanowire is carried out by heating. The experimental process is simple, the cost is low, the prepared selenium nanowire has high quality, and the selenium nanowire can be used for drug delivery, biological imaging, optical sensing and photocatalysis.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials and relates to a selenium nanowire material and its preparation method. Background Technology

[0002] Selenium (Se) is a p-type elemental semiconductor with a band gap of approximately 1.7 eV. Its crystal structure is a hexagonal close-packed structure, which can be described as a hexagonal close packing of selenium atoms, arranged at the vertices and center of the hexagons. Se atoms are connected by covalent bonds, and adjacent chains are connected by van der Waals forces. Compared with other chalcogenides, selenium nanomaterials possess anisotropic crystal structures, intrinsic chirality, high reactivity, and unique optical, electrical, photoconductive, and piezoelectric properties. One-dimensional semiconductor nanostructures have attracted widespread attention due to their excellent physical properties and potential applications in future nanodevices. Various methods for preparing one-dimensional selenium nanowires have been proposed in the prior art, such as template methods, hydrothermal methods, and pyrolysis methods. Chinese invention patent (CN202011375033.6) discloses a method for the large-scale preparation of ultralong selenium nanowires. This preparation process is a wet reaction, which is relatively cumbersome and complex, resulting in low crystal quality and limiting the material's properties and applications. Summary of the Invention

[0003] To address the shortcomings and deficiencies of existing preparation technologies, this invention provides a method for preparing selenium nanowire materials. The experimental process is simple, the raw materials are easy to obtain, and the prepared selenium nanowires have uniform morphology and good crystallinity, which is beneficial for subsequent performance exploration and research.

[0004] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0005] A method for preparing selenium nanowire materials, using silicon dioxide / silicon wafer as substrate, selenium powder as growth material, and vapor phase deposition method for depositing and growing selenium nanowires.

[0006] Specifically, it includes:

[0007] The deposition growth vessel includes a quartz tube, in which a raw material placement crucible and a substrate placement crucible are placed. The raw material placement crucible is located at the inlet end of the quartz tube, and the substrate placement crucible is located at the outlet end of the quartz tube.

[0008] The substrate is placed face down on the substrate placement crucible, and the selenium powder is placed in the raw material placement crucible.

[0009] Selenium nanowires are deposited and grown by heating.

[0010] Optionally, the raw material placement crucible and the substrate placement crucible are spaced 10-15 cm apart.

[0011] Optionally, the gas phase for deposition growth is a mixture of argon and hydrogen, with a total flow rate of 140 sccm; the reaction temperature for deposition growth is 200–550 °C.

[0012] Optionally, the flow rate of hydrogen in the gas phase is 0–50 sccm.

[0013] Optionally, the heating rate of the gas phase is 10–30 °C / min.

[0014] Optionally, the amount of selenium powder used is 10-30 mg.

[0015] Optionally, the deposition growth time is 2 to 20 minutes.

[0016] Optional, specifically including:

[0017] (1) Cut the silicon dioxide / silicon substrate into 1.5cm*4cm sheets and place them on the substrate placement crucible with the silicon dioxide side facing down;

[0018] (2) Place 10-30 mg of selenium powder in the crucible 10-15 cm in front of the substrate;

[0019] (3) Both the raw material placement crucible and the substrate placement crucible are placed in a quartz tube with an inner diameter of 50 mm and heated in a tube furnace to perform vapor deposition of selenium nanowires.

[0020] A selenium nanowire material is obtained by growing selenium nanowires using any of the methods described in this invention.

[0021] Advantages of this invention:

[0022] This invention successfully prepared high-quality selenium nanowires with uniform surface and no pollution using vapor deposition. Compared with the limitations of previous template methods on nanowire size, the complex process of hydrothermal methods, and the harsh high-temperature conditions of pyrolysis methods, the vapor deposition method used in this invention is simple, fast, has high yield, and is easy to operate. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the experimental preparation of the embodiments and comparative examples in this invention;

[0025] Figure 2 This is an optical microscope photograph of Example 1 of the present invention;

[0026] Figure 3This is the Raman spectrum of Example 1 in this invention;

[0027] Figure 4 This is an optical microscope photograph of Example 2 of the present invention;

[0028] Figure 5 This is the Raman spectrum of Example 2 in this invention;

[0029] Figure 6 This is an optical microscope photograph of Example 3 of the present invention;

[0030] Figure 7 This is the Raman spectrum of Example 3 in this invention;

[0031] Figure 8 This is an optical microscope photograph of Comparative Example 1 in this invention. Detailed Implementation

[0032] To make the objectives and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments, and the advantages of the invention will be demonstrated through the analysis of comparative examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0033] The selenium nanowire material prepared in this invention is grown directly on a silica / silicon substrate using a vapor deposition method. By controlling factors such as reaction temperature, reaction time, and gas flow ratio, the selenium nanowire material is obtained. The process is simple and low-cost. This invention successfully prepares high-quality selenium nanowire materials with uniform surface, no contamination, and a simple and easy-to-operate preparation process.

[0034] The method for preparing selenium nanowires of the present invention uses silicon dioxide / silicon wafer as substrate, selenium powder as growth material, and vapor phase deposition method to deposit and grow selenium nanowires.

[0035] Specifically, it includes:

[0036] The deposition growth container includes a quartz tube, inside which a raw material placement crucible and a substrate placement crucible are placed. The raw material placement crucible is located at the gas inlet end of the quartz tube, and the substrate placement crucible is located at the gas outlet end of the quartz tube. The silica side of the substrate is placed on the substrate placement crucible, and selenium powder is placed in the raw material placement crucible. Heating is then used to deposit and grow selenium nanowires.

[0037] In this invention, the raw material placement crucible and the substrate placement crucible are 10-15 cm apart.

[0038] In this invention, the gas phase for deposition growth is a mixture of argon and hydrogen, with a total flow rate of 140 sccm; the reaction temperature for deposition growth is 200–550 °C.

[0039] In this invention, the flow rate of hydrogen in the gas phase is 0–50 sccm.

[0040] In this invention, the heating rate of the gas phase is 10–30 °C / min.

[0041] In this invention, the amount of selenium powder used is 10-30 mg.

[0042] In this invention, the deposition growth time is 2 to 20 minutes.

[0043] Specifically, it includes:

[0044] (1) Cut the silicon dioxide / silicon substrate into 1.5cm*4cm sheets and place them on the substrate placement crucible with the silicon dioxide side facing down;

[0045] (2) Place 10-30 mg of selenium powder in the crucible 10-15 cm in front of the substrate;

[0046] (3) Both the raw material placement crucible and the substrate placement crucible are placed in a quartz tube with an inner diameter of 50 mm and heated in a tube furnace to perform vapor deposition of selenium nanowires.

[0047] A selenium nanowire material is obtained by growing selenium nanowires using any of the methods of this invention.

[0048] Specifically, the preparation method of selenium nanowires of the present invention uses silicon dioxide / silicon wafers as substrates, and grows selenium nanowires on the silicon dioxide surface of the substrate using a vapor phase deposition method. The vapor phase for vapor phase deposition is a mixture of argon and hydrogen, with a total flow rate of 140 sccm. The reaction temperature for vapor phase deposition is 200–550°C; the flow rate of hydrogen is 0–50 sccm; the heating rate of hydrogen is 10–30°C / min; the deposition growth time is 2–20 min; the amount of selenium powder used is 10–30 mg; and the distance between the selenium powder and the substrate is 10–15 cm. Experiments have shown that, using the raw materials and process conditions provided in this invention, physical vapor phase deposition needs to be performed in two corundum crucibles to obtain selenium nanowires. Without using corundum crucibles, such as quartz tubes, selenium nanowires cannot be obtained on the substrate.

[0049] Unless otherwise specified, all raw materials used in the following experiments are commercially available, and all methods used are conventional experimental methods in this field.

[0050] Example 1:

[0051] This embodiment provides a method for preparing selenium nanowire materials on a silicon dioxide / silicon substrate, including the following steps:

[0052] Step 1: Cut the silicon dioxide / silicon substrate into 1.5×4cm sheets and clean them with an air gun. Place the silicon dioxide side down on the corundum crucible.

[0053] Step 2: Add 10mg of selenium powder to the corundum crucible located 10cm from the front end of the substrate.

[0054] Step 3: Place the corundum crucible into a quartz tube with an outer diameter of 50 mm. Position the corundum crucible with added selenium powder near the gas inlet, ensuring the selenium powder is 10 cm away from the substrate. Heat the crucible in the center of a tube furnace to perform vapor deposition of selenium nanowire materials. Figure 1 As shown in a.

[0055] Step 4: Introduce 100 sccm of argon gas for 30 minutes to thoroughly remove residual oxygen from the tube. Then, continue introducing 90 sccm of argon gas and 50 sccm of hydrogen gas, heating the tube furnace to 200°C at a heating rate of 30°C / min and holding for 20 minutes. Afterward, turn off the heater and allow it to cool naturally to room temperature. The resulting optical image of the selenium nanowire material is shown below. Figure 2 As shown. Raman spectrum as Figure 3 As shown, the prepared material is selenium nanowires.

[0056] Example 2:

[0057] This embodiment provides a method for preparing selenium nanowire materials on a silicon dioxide / silicon substrate, including the following steps:

[0058] Step 1: Cut the silicon dioxide / silicon substrate into 1.5×4cm sheets and clean them with an air gun. Place the silicon dioxide side down on the corundum crucible.

[0059] Step 2: Add 20mg of selenium powder to the corundum crucible located 12cm from the front end of the substrate.

[0060] Step 3: Place the corundum crucible into a quartz tube with an outer diameter of 50 mm. Position the corundum crucible with added selenium powder near the gas inlet, ensuring the selenium powder is 12 cm away from the substrate. Heat the crucible in the center of a tube furnace to perform vapor deposition of selenium nanowire materials. Figure 1 As shown in a.

[0061] Step 4: Introduce 100 sccm of argon gas for 30 minutes to thoroughly remove residual oxygen from the tube. Then, continue introducing 90 sccm of argon gas and 50 sccm of hydrogen gas, heating the tube furnace to 350°C at a heating rate of 30°C / min and holding for 10 minutes. Afterward, turn off the heater and allow it to cool naturally to room temperature. The resulting optical image of the selenium nanowire material is shown below. Figure 4 As shown. Raman spectrum as Figure 5 As shown, the prepared material is selenium nanowires.

[0062] Example 3:

[0063] This embodiment provides a method for preparing selenium nanowire materials on a silicon dioxide / silicon substrate, including the following steps:

[0064] Step 1: Cut the silicon dioxide / silicon substrate into 1.5×4cm sheets and clean them with an air gun. Place the silicon dioxide side down on the corundum crucible.

[0065] Step 2: Add 30mg of selenium powder to the corundum crucible located 10cm from the front end of the substrate.

[0066] Step 3: Place the corundum crucible into a quartz tube with an outer diameter of 50 mm. Position the corundum crucible with added selenium powder near the gas inlet, ensuring the selenium powder is 15 cm away from the substrate. Heat the crucible in the center of a tube furnace to perform vapor deposition of selenium nanowire materials. Figure 1 As shown in a.

[0067] Step 4: Introduce 100 sccm of argon gas for 30 minutes to thoroughly remove residual oxygen from the tube. Then, continue introducing 120 sccm of argon gas and 20 sccm of hydrogen gas, heating the tube furnace to 550°C at a heating rate of 30°C / min and holding for 2 minutes. Afterward, turn off the heater and allow it to cool naturally to room temperature. The resulting optical image of the selenium nanowire material is shown below. Figure 6 As shown. Raman spectrum as Figure 7 As shown, the prepared material is selenium nanowires.

[0068] Comparative Example 1:

[0069] This comparative example presents a method for preparing materials without using two corundum crucibles, including the following steps.

[0070] Step 1: Cut the silicon dioxide / silicon substrate into 1.5×4cm sheets and clean them with an air gun. Place them with the silicon dioxide side facing up inside a single-sealed quartz tube.

[0071] Step 2: Add 10mg of selenium powder to one end of the quartz tube, 12cm from the front end of the substrate.

[0072] Step 3: Place the quartz tube into a quartz tube with an outer diameter of 50mm, and place it directly in the center of the tubular atmosphere furnace heating position, such as... Figure 1 As shown in b.

[0073] Step 4: Same as in Example 1, the optical photographs of the material obtained at this stage are as follows. Figure 8 As shown.

[0074] Compared with Example 1, it can be seen that without using two corundum crucibles, and with other conditions remaining unchanged, non-selenium nanowire materials can be prepared on the substrate.

[0075] Comparative Example 2:

[0076] Chinese invention patent (CN202010118719.0) discloses a solution method for preparing selenium nanowires, including the following steps:

[0077] Step 1: Dissolve selenourea in distilled water at room temperature to form a solution, then stir on a magnetic stirrer to obtain brick-red amorphous selenium spheres; the stirring time is 30-60 min, the speed is 750-900 rpm, and the solution concentration is 0.01-0.1 mol / L.

[0078] Step 2: Disperse the amorphous selenium spheres from Step 1 in deionized water and anhydrous ethanol and perform repeated ultrasonic washing and centrifugation three times; let stand in the dark to obtain selenium nanowires.

[0079] The process is quite complex, requiring strict control of parameters such as solution concentration and stirring time. The operation is cumbersome and the material's performance is easily affected by impurities.

[0080] This invention uses vapor deposition to prepare selenium nanowires, which uses simple raw materials, has a high yield, and is highly controllable. It does not require large amounts of organic solvents or other chemical reagents, thus reducing environmental pollution.

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing selenium nanowire materials, characterized in that, Selenium nanowires were deposited and grown using a chemical vapor deposition method with silicon dioxide / silicon wafers as substrates and selenium powder as growth material. Specifically, it includes: The deposition growth container includes a quartz tube, inside which a raw material placement crucible and a substrate placement crucible are placed. The raw material placement crucible is located at the gas inlet end of the quartz tube, and the substrate placement crucible is located at the gas outlet end of the quartz tube. The raw material placement crucible and the substrate placement crucible are 10-15 cm apart. The amount of selenium powder used is 10-30 mg. The substrate is placed with its silicon dioxide side down on a substrate placement crucible, and selenium powder is placed in a raw material placement crucible; heating is then used to deposit and grow selenium nanowires.

2. The method for preparing selenium nanowire materials according to claim 1, characterized in that, The gas phase for deposition growth is a mixture of argon and hydrogen, with a total flow rate of 140 sccm. The reaction temperature for the deposition growth is 200–550 °C.

3. The method for preparing selenium nanowire materials according to claim 1 or 2, characterized in that, The flow rate of hydrogen in the gas phase is 0~50 sccm.

4. The method for preparing selenium nanowire materials according to claim 1 or 2, characterized in that, The heating rate of the gas phase is 10–30 °C / min.

5. The method for preparing selenium nanowire materials according to claim 1 or 2, characterized in that, The deposition growth time is 2 to 20 minutes.

6. The method for preparing selenium nanowire materials according to claim 1 or 2, characterized in that, Specifically, it includes: (1) The silicon dioxide / silicon substrate is cut into 1.5cm pieces. A 4cm sheet, with the silicon dioxide side facing down, is placed on a substrate in a crucible; (2) Place 10-30 mg of selenium powder in the crucible 10-15 cm in front of the substrate; (3) Both the raw material placement crucible and the substrate placement crucible are placed in a quartz tube with an inner diameter of 50 mm and heated in a tube furnace to perform vapor deposition of selenium nanowires.

7. A selenium nanowire material, characterized in that, The selenium nanowires were obtained by growing them using the method described in any one of claims 1-6.

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