Preparation method of one-dimensional platinum diselenide nanobelt and prepared platinum diselenide nanobelt

Abstract

Disclosed is a method for preparing one-dimensional platinum diselenide nanobelts, which can simultaneously achieve large-scale, high-quality preparation and self-oriented preparation. The method comprises: (1) preparing a one-dimensional platinum diselenide nanobelt on a SiO 2 (1) spin-coating polymethyl methacrylate (PMMA) on a Si substrate and using electron beam exposure to produce a nanobelt pattern; (2) using a developer to dissolve the PMMA in the exposed part and removing the residual developer with a fixer; (3) using electron beam evaporation to deposit a layer of metal platinum on the substrate, using anhydrous acetone to dissolve the PMMA, and stripping off the metal platinum in the non-nanobelt area to obtain a metal platinum nanobelt; (4) placing the metal platinum nanobelt in the middle position of a tubular furnace, placing a selenium source at an upstream position, and heating the selenium source to 220-300°C; (5) sealing the cavity of the tubular furnace and evacuating it, using nitrogen with a flow rate of 40-70sccm as the carrier gas, heating the cavity to 420-500°C for one hour, and then naturally cooling to room temperature to obtain a platinum diselenide nanobelt.

Description

Technical Field

[0001] The invention relates to the field of low-dimensional nanomaterials, and in particular to a method for preparing a one-dimensional platinum diselenide nanobelt, and a platinum diselenide nanobelt prepared according to the preparation method. Background Art

[0002] Platinum diselenide is an emerging two-dimensional transition metal chalcogenide material, whose band gap can be tuned in the range of 0 to 1.2 eV by controlling the thickness. Due to its rich electrical and optical properties, platinum diselenide is considered to have a wide range of potential applications in micro-nanoelectronics and optoelectronics. Platinum diselenide has different physical and chemical properties in different lattice orientations, and has better conductivity in the zigzag direction than in the armchair direction. Its anisotropy has also attracted the attention of researchers. The preparation of one-dimensional nanoribbons is a common method to study and apply the anisotropy of two-dimensional materials.

[0003] There are currently two main methods for preparing one-dimensional nanobelts experimentally. One is to determine the lattice orientation of the two-dimensional material through high-resolution characterization methods (such as angle-resolved polarized Raman spectroscopy), and then use electron beam exposure and other lithography methods for patterning. This method can accurately obtain one-dimensional nanobelts with a certain lattice orientation, but its complex preparation process determines that this method is not suitable for large-scale nanobelt growth. Another method is chemical cutting, which chemically cuts bulk two-dimensional materials through liquid-phase electrochemical exfoliation to obtain a one-dimensional nanobelt structure. This method can achieve large-scale preparation of one-dimensional nanobelts, but it will produce by-products such as two-dimensional nanosheets and zero-dimensional quantum dots. In addition, various impurity ions and functional groups in the solution will affect the quality and uniformity of the nanobelts.

[0004] Except for the present invention, there is no method for synthesizing zigzag self-oriented platinum diselenide nanobelts. Hao Guolin and others from Xiangtan University invented a method for preparing a single-layer tungsten diselenide nanobelt based on a spatial confinement strategy. The specific steps of the method are as follows:

[0005] (1) cleaning the substrate;

[0006] (2) placing the treated substrate in the heating center of a high-temperature tube furnace, and placing the alumina boat containing selenium powder in the upstream, and the boat containing tungsten trioxide and the substrate in the downstream heating center in the order of gas flow from upstream to downstream;

[0007] (3) introducing argon and hydrogen into the reaction chamber of the high-temperature tube furnace to clean the reaction chamber;

[0008] (4) Raise the temperature of the tube furnace to 800-850°C, so that the temperature of the selenium powder is controlled at 400-

[0009] 450℃, the temperature of tungsten trioxide is controlled at 800~850℃, and tungsten diselenide is grown;

[0010] (5) After the growth of tungsten diselenide is completed, the temperature is lowered to room temperature, and the argon and hydrogen gases are turned off at the same time, thereby obtaining a single-layer tungsten diselenide nanoribbon.

[0011] Tungsten diselenide is a layered material similar in structure to platinum diselenide, so its preparation method is also applicable to platinum diselenide to a certain extent. The advantages of this method are:

[0012] (1) It can realize the spatial confined growth of tungsten diselenide nanoribbons;

[0013] (2) The growth method is simple and easy, and batch growth can be achieved.

[0014] However, this method also has the following disadvantages:

[0015] (1) The lattice orientation of the grown nanoribbons cannot be controlled;

[0016] (2) The thickness and width of the growing nanoribbons cannot be freely controlled. Summary of the invention

[0017] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to provide a method for preparing one-dimensional platinum diselenide nanobelts, which can simultaneously achieve large-scale, high-quality preparation and self-oriented preparation.

[0018] The technical solution of the present invention is: a method for preparing the one-dimensional platinum diselenide nanobelt, which comprises the following steps:

[0019] (1) Spin-coating polymethyl methacrylate (PMMA) on SiO2 / Si substrate and using electron beam exposure to produce nanoribbon patterns;

[0020] (2) using a developer to dissolve the PMMA in the exposed part, and using a fixer to remove the remaining developer;

[0021] (3) using electron beam evaporation to deposit a layer of metal platinum on the substrate, using anhydrous acetone to dissolve PMMA, and stripping off the metal platinum in the non-nanobelt area to obtain metal platinum nanobelts;

[0022] (4) placing the metal platinum nanobelt in the middle of the tube furnace, placing a selenium source at the upstream position, and heating the selenium source to 220-300° C.;

[0023] (5) After the cavity of the tube furnace is sealed and evacuated, nitrogen gas with a flow rate of 40 to 70 sccm is used as a carrier gas, the cavity is heated to 420 to 500° C. for one hour, and then naturally cooled to room temperature to obtain platinum diselenide nanobelts.

[0024] The zigzag-oriented platinum diselenide nanobelt has a lower surface energy than the armchair orientation, so it will spontaneously grow into a zigzag-oriented platinum diselenide nanobelt during the selenization process of the platinum nanobelt. The present invention utilizes this characteristic of the platinum diselenide nanobelt, deposits a layer of metal platinum on the substrate by electron beam evaporation, dissolves PMMA by anhydrous acetone, and strips off the metal platinum in the non-nanobelt area to obtain the metal platinum nanobelt, places the metal platinum nanobelt in the middle position of the tube furnace, places a selenium source at the upstream position, heats the selenium source to 220-300°C, seals the cavity of the tube furnace and evacuates it, and uses nitrogen with a flow rate of 40-70sccm as a carrier gas to heat the cavity to 420-500°C for one hour, and then naturally cools to room temperature to obtain the platinum diselenide nanobelt, thereby realizing the preparation of zigzag self-oriented platinum diselenide nanobelt. Therefore, large-scale, high-quality preparation and self-oriented preparation can be achieved at the same time.

[0025] Also provided is a one-dimensional platinum diselenide nanobelt prepared by the preparation method, which is a substrate with a zigzag self-oriented platinum diselenide nanobelt. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of spin coating PMMA on SiO2 / Si substrate in the method for preparing one-dimensional platinum diselenide nanobelts according to the present invention.

[0027] Figure 2 The substrate is a substrate after the nanobelt patterning is completed by using EBL in the preparation method of the one-dimensional platinum diselenide nanobelt according to the present invention.

[0028] Figure 3 The substrate is a substrate on which metal platinum is deposited by using electron beam evaporation technology in the preparation method of the one-dimensional platinum diselenide nanobelt according to the present invention.

[0029] Figure 4 The substrate is a substrate with platinum nanobelts after development and fixing in the method for preparing one-dimensional platinum diselenide nanobelts according to the present invention.

[0030] Figure 5 The substrate is a substrate with a zigzag self-oriented platinum diselenide nanobelt after being selenized in the preparation method of the one-dimensional platinum diselenide nanobelt according to the present invention.

[0031] Figure 6 The figure is a flow chart of the method for preparing one-dimensional platinum diselenide nanoribbons according to the present invention.

[0032] Description of labels:

[0033] 1 is a silicon substrate, 2 is a silicon dioxide layer grown on the silicon substrate by thermal oxidation, 3 is electron beam gel PMMA, 4 is metal platinum, and 5 is a zigzag self-oriented platinum diselenide nanobelt. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0035] It should be noted that the term "comprises" and any variations in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or equipment.

[0036] like Figure 6 As shown, the method for preparing the one-dimensional platinum diselenide nanobelt comprises the following steps:

[0037] (1) Spin-coating polymethyl methacrylate (PMMA) on SiO2 / Si substrate and using electron beam exposure to produce nanoribbon patterns;

[0038] (2) using a developer to dissolve the PMMA in the exposed part, and using a fixer to remove the remaining developer;

[0039] (3) using electron beam evaporation to deposit a layer of metal platinum on the substrate, using anhydrous acetone to dissolve PMMA, and stripping off the metal platinum in the non-nanobelt area to obtain metal platinum nanobelts;

[0040] (4) placing the metal platinum nanobelt in the middle of the tube furnace, placing a selenium source at the upstream position, and heating the selenium source to 220-300° C.;

[0041] (5) After the cavity of the tube furnace is sealed and evacuated, nitrogen gas with a flow rate of 40 to 70 sccm is used as a carrier gas, the cavity is heated to 420 to 500° C. for one hour, and then naturally cooled to room temperature to obtain platinum diselenide nanobelts.

[0042] The zigzag-oriented platinum diselenide nanobelt has a lower surface energy than the armchair orientation, so it will spontaneously grow into a zigzag-oriented platinum diselenide nanobelt during the selenization process of the platinum nanobelt. The present invention utilizes this characteristic of the platinum diselenide nanobelt, deposits a layer of metal platinum on the substrate by electron beam evaporation, dissolves PMMA by anhydrous acetone, and strips off the metal platinum in the non-nanobelt area to obtain the metal platinum nanobelt, places the metal platinum nanobelt in the middle position of the tube furnace, places a selenium source at the upstream position, heats the selenium source to 220-300°C, seals the cavity of the tube furnace and evacuates it, and uses nitrogen with a flow rate of 40-70sccm as a carrier gas to heat the cavity to 420-500°C for one hour, and then naturally cools to room temperature to obtain the platinum diselenide nanobelt, thereby realizing the preparation of zigzag self-oriented platinum diselenide nanobelt. Therefore, large-scale, high-quality preparation and self-oriented preparation can be achieved at the same time.

[0043] Preferably, in the step (1), the electron beam gel PMMA, model RE300.40.9, is spin-coated at a speed of 3000 rpm and the spin coating lasts for 60 seconds.

[0044] Preferably, in the step (1), the spin-coated substrate is baked at 170° C. for 15 minutes, and a nanobelt pattern is generated on the substrate by electron beam lithography.

[0045] Preferably, in step (1), the electron beam lithography process uses an NB5 electron beam lithography machine.

[0046] Preferably, in the step (2), a developer having a volume ratio of methyl isobutyl ketone (MIBK) to ethanol of 3:1 is used for development, and the development time is 5 to 10 minutes; and a fixing solution of anhydrous ethanol is used for fixing, and the fixing time is 50 seconds.

[0047] Preferably, in the step (3), 3 to 10 nm of metal platinum is deposited on the substrate having the nanobelt pattern by electron beam evaporation process.

[0048] Preferably, in step (4), the selenium source is selenium powder with a purity of 99.99%.

[0049] Preferably, in step (5), the purity of nitrogen is 99.99%.

[0050] Also provided is a one-dimensional platinum diselenide nanobelt prepared by the preparation method, which is a substrate with a zigzag self-oriented platinum diselenide nanobelt.

[0051] A specific embodiment of the present invention is given below.

[0052] A one-dimensional platinum diselenide nanobelt, the preparation method comprising the following steps:

[0053] S1. Spin-coat PMMA (Re300.40.9) on a SiO2 / Si substrate at a speed of 3000 rpm for 60 seconds; bake the spin-coated substrate at 170°C for 15 minutes.

[0054] S2. Generate nanobelt patterns on the substrate by electron beam lithography; use a developer (volume ratio of MIBK: ethanol = 3:1) for development, and the development time is 5 to 10 minutes; use a fixer (anhydrous ethanol) for fixing, and the fixing time is 50 seconds.

[0055] S3. Deposit 3 to 10 nm of metal platinum on a substrate with an existing nanobelt pattern by electron beam evaporation; use anhydrous acetone to dissolve PMMA, peel off the metal platinum film in the non-nanoband area, and obtain metal platinum nanobelts.

[0056] S4. Place the metal platinum nanobelt in the middle position of the tubular furnace; place a selenium source (selenium powder with a purity of 99.99%) at the upstream position, and heat the selenium source to 220-300°C; seal the cavity of the tubular furnace and evacuate it, then use nitrogen with a flow rate of 40-70sccm as a carrier gas, heat the cavity to 420-500°C for one hour, and then naturally cool to room temperature to obtain platinum diselenide nanobelts.

[0057] The raw materials in the embodiments can be obtained from commercial sources, as follows:

[0058] Selenium powder, purity 99.99%;

[0059] Nitrogen, purity 99.99%;

[0060] Platinum particles (target material);

[0061] Electron beam glue polymethyl methacrylate PMMA (model RE300.40.9);

[0062] NB5 electron beam lithography machine;

[0063] Developer (mixed solution of methyl isobutyl ketone MIBK and ethanol, volume ratio of 3:1);

[0064] Fixing solution (absolute ethanol);

[0065] Anhydrous acetone;

[0066] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the present technical field.

[0067] The zigzag-oriented platinum diselenide nanobelt has a lower surface energy than the armchair-oriented platinum diselenide nanobelt, and thus will spontaneously grow into a zigzag-oriented platinum diselenide nanobelt during the selenization process of the platinum nanobelt. The key technical point of the present invention is that, by utilizing this characteristic of the platinum diselenide nanobelt, a two-step synthesis strategy of "growing platinum nanobelts" and "selenizing the platinum nanobelts" is adopted to achieve the preparation of the zigzag self-oriented platinum diselenide nanobelt.

[0068] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a one-dimensional platinum diselenide nanoribbon, characterized in that: It includes the following steps: (1) Spin-coating polymethyl methacrylate (PMMA) on SiO2 / Si substrate and using electron beam exposure to produce nanoribbon patterns; (2) using a developer to dissolve the PMMA in the exposed part, and using a fixer to remove the remaining developer; (3) using electron beam evaporation to deposit a layer of metal platinum on the substrate, using anhydrous acetone to dissolve PMMA, and stripping off the metal platinum in the non-nanobelt area to obtain metal platinum nanobelts; (4) placing the metal platinum nanobelt in the middle of the tube furnace, placing a selenium source at the upstream position, and heating the selenium source to 220-300° C.; (5) After the cavity of the tube furnace is sealed and evacuated, nitrogen gas with a flow rate of 40 to 70 sccm is used as a carrier gas, the cavity is heated to 420 to 500° C. for one hour, and then naturally cooled to room temperature to obtain platinum diselenide nanobelts.

2. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 1, characterized in that: In the step (1), the electron beam gel PMMA, model RE300.40.9, is spin-coated at a rotation speed of 3000 rpm, and the spin coating lasts for 60 seconds.

3. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 2, characterized in that: In the step (1), the spin-coated substrate is baked at 170° C. for 15 minutes, and a nanobelt pattern is generated on the substrate by electron beam lithography.

4. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 3, characterized in that: In the step (1), the electron beam lithography process uses an NB5 electron beam lithography machine.

5. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 4, characterized in that: In the step (2), a developer having a volume ratio of methyl isobutyl ketone (MIBK) to ethanol of 3:1 is used for development, and the development time is 5 to 10 minutes; and a fixing solution of anhydrous ethanol is used for fixing, and the fixing time is 50 seconds.

6. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 5, characterized in that: In the step (3), 3 to 10 nm of metal platinum is deposited on the substrate having the nanobelt pattern by electron beam evaporation process.

7. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 6, characterized in that: In the step (4), the selenium source is selenium powder with a purity of 99.99%.

8. The method for preparing one-dimensional platinum diselenide nanoribbons according to claim 7, characterized in that: In the step (5), the purity of nitrogen is 99.99%.

Images