Preparation method of Sb4 self-assembled structure

Abstract

The application relates to a preparation method of an Sb4 self-assembled structure and belongs to the technical field of nanometer materials. A gold single crystal substrate is prepared; antimony powder is evaporated and deposited on the gold single crystal substrate to obtain a substrate and Sb4 molecular self-assembled chains deposited on the substrate, and the deposition process controls the temperature of the gold single crystal substrate to be 25-30 DEG C; the substrate and the Sb4 molecular self-assembled chains deposited on the substrate are subjected to first temperature rising to a growth temperature for heat preservation treatment to obtain small-area and dispersed Sb4 molecular self-assembled islands; then, the small-area self-assembled islands prepared are used as nucleation sites for growth, that is, the antimony powder is evaporated and deposited on the surface of the gold single crystal substrate with the small-area self-assembled islands to obtain a gold single crystal substrate with coexistence of small-area Sb4 molecular self-assembled islands and Sb4 molecular self-assembled chains, and the deposition process controls the temperature of the substrate to be 25-30 DEG C; the obtained gold single crystal substrate with coexistence of small-area Sb4 molecular self-assembled islands and Sb4 molecular self-assembled chains is subjected to second temperature rising to a growth temperature for heat preservation treatment to obtain large-area Sb4 molecular self-assembled islands. The Sb4 molecular self-assembled structure prepared by the application has regular shape structure, and the width of the self-assembled structure is mostly above 100 nm.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of Sb4 self-assembly structure and belongs to the technical field of nanomaterials. BACKGROUND

[0002] In recent years, researchers have paid extensive attention to the self-assembly and surface chemical reaction of carbon-based molecules on various metal surfaces, which makes them dominate the bottom-up construction of large-area two-dimensional materials, but there are few cases of the bottom-up construction of two-dimensional materials by other non-carbon molecules on metal surfaces. Many carbon-based molecules have the defects of difficult separation of precursor molecules and complex reaction product types on metal surfaces, so it is of great significance to develop non-carbon molecules for the bottom-up construction of two-dimensional materials.

[0003] As a group VA element, antimony has five outer electrons, so it can form various three-dimensional molecules such as Sb2, Sb3, Sb4 and Sb7, and thus theoretically can form various two-dimensional self-assembly structures on metal surfaces. However, the structures of antimonene discovered at present are mainly armchair (alpha phase) and honeycomb (beta phase) structures. Since the substrates for growing antimonene are mainly Ag (111) and Cu (111) substrates with strong catalytic ability, the Sb molecules deposited on the metal surface have already reacted, and the Sb and the substrate are prone to alloying at room temperature, so it is difficult to observe the original structure of the Sb molecules deposited on the metal surface. In order to solve this problem, we choose Au (111) substrate as the metal substrate for molecular deposition, because the catalytic activity of the Au (111) surface is weaker than that of the Ag (111) and Cu (111) metal substrate surfaces, and the alloying of Sb does not easily occur at room temperature. Moreover, the proportion of Sb4 molecules in antimony vapor is the largest, so we can observe the original state of Sb4 molecules and the subsequent self-assembly process on the Au (111) surface. This provides a reference for the surface synthesis process of antimonene. SUMMARY

[0004] In view of the problems and deficiencies of the prior art, the application provides a preparation method of Sb4 self-assembly structure. The Sb4 molecules do not alloy with the Au (111) surface at room temperature, so that the Sb powder is deposited on the gold substrate surface to obtain a sample with Sb4 self-assembly chains on the gold substrate. The sample is heated to a growth temperature and then annealed, Sb powder is deposited on the surface of the sample, the sample is heated to a growth temperature and then annealed, and finally a large-area Sb4 molecule self-assembly island product is obtained.

[0005] A preparation method of Sb4 self-assembly structure, which comprises the following specific steps:

[0006] Step 1, preparing a gold single crystal substrate;

[0007] Step 2, antimony powder is evaporated and deposited on the gold single crystal substrate of step 1 to obtain a substrate and self-assembled Sb4 molecular chains deposited on the substrate, and the deposition process controls the temperature of the Sb4 molecular chains and the gold single crystal substrate on the substrate to be 25-30℃;

[0008] Step 3, the Sb4 molecular chains and the gold single crystal substrate of step 2 are subjected to a first temperature rise to the growth temperature for heat preservation treatment to obtain a small-area Sb4 molecular self-assembly island;

[0009] Step 4, then the antimony powder is evaporated and deposited on the substrate and Sb4 molecular self-assembly island treated in step 3 to obtain a gold substrate coexisting with a small-area Sb4 molecular self-assembly island and Sb4 molecular self-assembly chain, and the deposition process controls the temperature of the substrate and the deposit to be 25-30℃;

[0010] Step 5, the small-area Sb4 molecular self-assembly island and Sb4 molecular self-assembly chain coexisting gold substrate obtained in step 4 is subjected to a second temperature rise to the growth temperature for heat preservation treatment to obtain a large-area Sb4 molecular self-assembly island.

[0011] The preparation process of the gold single crystal substrate is specifically:

[0012] Step 1.1, in an ultra-high vacuum cavity, argon ion sputtering treatment is performed on a gold substrate to obtain a gold substrate;

[0013] Step 1.2, the gold substrate obtained in step 1.1 is heated to 450℃ and heat preserved for 10-30min to obtain a gold single crystal substrate.

[0014] The antimony powder evaporation temperature in step 2 is 230-235℃, and the deposition time is 5-10min.

[0015] The growth temperature in step 3 is 100℃, and the heat preservation time is 30min.

[0016] The antimony powder evaporation temperature in step 4 is 230-235℃, and the deposition time is 20-30min.

[0017] The growth temperature in step 5 is 150℃, and the heat preservation time is 30min.

[0018] The ratio of the deposition amount of the two times of Sb4 molecular deposition is about 1:4.

[0019] The beneficial effects of the present application are:

[0020] (1) The present application can prepare Sb4 molecular self-assembly island products, which have regular shape structure and the width of the island is mostly above 100nm;

[0021] (2) The large-area Sb4 molecular self-assembly island prepared by the method has a hexagonal island structure composed of Sb4 molecules arranged upward and downward alternately.

[0022] (3) The Sb4 molecular self-assembly island prepared by the method can form two kinds of corners with the substrate, thereby forming two kinds of Moire superstructures. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a scanning tunneling microscope image of a large-area Sb4 molecular self-assembly island prepared by the method of Example 1 (two kinds of corners, 19.1° and 0° corners, respectively);

[0024] Figure 2 is a scanning tunneling microscope image of a large-area Sb4 molecular self-assembly island prepared by the method of Example 1 (two kinds of corners, 19.1° and 0° corners, respectively);

[0025] Figure 3 is a scanning tunneling microscope image of a large-area Sb4 molecular self-assembly island prepared by the method of Example 1 (two kinds of corners, 19.1° and 0° corners, respectively). DETAILED DESCRIPTION

[0026] The application will be further described below in conjunction with the drawings and specific embodiments.

[0027] Test instruments and equipment:

[0028] Low-temperature scanning tunneling microscope: purchased from Omicron, Germany.

[0029] K-cell molecular evaporation source: purchased from Omicron, Germany.

[0030] Argon ion gun: purchased from Omicron, Germany.

[0031] Raw materials:

[0032] Antimony powder: purchased from Sigma-Aldrich, purity 99.999%.

[0033] Gold single crystal: purchased from MaTecK, purity 99.999%.

[0034] Example 1

[0035] The preparation method of the Sb4 self-assembly structure includes the following specific steps:

[0036] Step 1, preparing a gold single crystal substrate; the preparation process of the gold single crystal substrate is as follows:

[0037] Step 1.1, performing argon ion sputtering treatment on the gold substrate in an ultrahigh vacuum chamber to obtain a gold substrate;

[0038] Step 1.2, heating the gold substrate obtained in step 1.1 to 450℃ for 10 min to obtain a gold single crystal substrate;

[0039] Step 2, evaporating and depositing 100 mg of antimony powder on the 50 g gold single crystal substrate obtained in step 1 using a thermal resistance K-cell molecular evaporation source at an evaporation temperature of 230℃ to obtain a substrate and Sb4molecular self-assembly chains deposited on the substrate, and the temperature of the substrate and the deposited Sb4molecular self-assembly chains is controlled to be 30℃ during the deposition process, and the deposition time is 5-10 min;

[0040] Step 3, performing a first temperature rising to a growth temperature for the substrate and the deposited Sb4molecular self-assembly chains obtained in step 2 to obtain small-area Sb4molecular self-assembly islands, and the growth temperature is 100℃, and the holding time is 30 min;

[0041] Step 4, then evaporating and depositing 400 mg of antimony powder on the 50 g substrate and Sb4molecular self-assembly islands treated in step 3 using a thermal resistance K-cell molecular evaporation source at an evaporation temperature of 230℃ to obtain a gold substrate with coexisting Sb4molecular self-assembly chains and small-area Sb4molecular self-assembly islands, and the temperature of the substrate and the deposited material is controlled to be 30℃ during the deposition process, and the deposition time is 20-30 min;

[0042] Step 5, performing a second temperature rising to a growth temperature for the gold substrate with coexisting Sb4molecular self-assembly chains and small-area Sb4molecular self-assembly islands obtained in step 4 to obtain large-area Sb4molecular self-assembly islands, and the growth temperature is 150℃, and the holding time is 30 min.

[0043] The scanning tunneling microscope image of the large-area Sb4molecular self-assembly islands prepared in this example is shown in Figure 1 It can be seen from Figure 1 that the product of the present application is a large-area Sb4molecular self-assembly island, and the turning angle of figure a is 19.1°, and the turning angle of figure b is 0°.

[0044] The scanning tunneling microscope atomic resolution image and the unit cell structure diagram (figure a) and the period diagram (figure b) of the large-area Sb4molecular self-assembly islands prepared in this example are shown in Figure 2 It can be seen from (a) and (b) that the lattice constant a of the unit cell of the large-area Sb4molecular self-assembly island is 0.74 nm.

[0045] The scanning tunneling microscope image, the calculation simulation diagram and the atomic model diagram of the large-area Sb4molecular self-assembly island chain prepared in Example 1 are shown in Figure 3 It can be seen from Figure 3The large-area Sb4 molecular self-assembly island prepared according to the preparation method of the embodiment of the present application can be directly and effectively proved to be a hexagonal island composed of Sb4 molecules arranged upward and downward alternately.

[0046] Embodiment 2

[0047] The preparation method of the large-area Sb4 molecular self-assembly structure includes the following specific steps:

[0048] Step 1, preparing a gold single crystal substrate; the preparation process of the gold single crystal substrate is specifically as follows:

[0049] Step 1.1, performing argon ion sputtering treatment on the gold substrate in an ultrahigh vacuum cavity to obtain a gold substrate;

[0050] Step 1.2, heating the gold substrate obtained in step 1.1 to 450 DEG C and keeping the temperature for 30 min to obtain a gold single crystal substrate;

[0051] Step 2, evaporating and depositing 100 mg of antimony powder on the 50 g gold single crystal substrate of step 1 by using a thermal resistance type K-cell molecular evaporation source at an evaporation temperature of 230 DEG C to obtain a substrate and Sb4 molecular self-assembly chains deposited on the substrate; the temperature of the substrate and the Sb4 molecular self-assembly chains and the gold single crystal substrate is controlled to be 30 DEG C during the deposition process, and the deposition time is 5-10 min;

[0052] Step 3, performing first temperature rising to the growth temperature for the substrate and the Sb4 molecular self-assembly chains deposited on the substrate of step 2 to obtain small-area Sb4 molecular self-assembly islands; the growth temperature is 100 DEG C, and the temperature keeping time is 30 min;

[0053] Step 4, then evaporating and depositing 400 mg of antimony powder on the 50 g substrate and Sb4 molecular self-assembly islands treated in step 3 by using a thermal resistance type K-cell molecular evaporation source at an evaporation temperature of 230 DEG C to obtain a gold substrate in which Sb4 molecular self-assembly chains and small-area Sb4 molecular self-assembly islands coexist; the temperature of the substrate and the deposited material is controlled to be 30 DEG C during the deposition process, and the deposition time is 20-30 min;

[0054] Step 5, performing second temperature rising to the growth temperature for the gold substrate in which Sb4 molecular self-assembly chains and small-area Sb4 molecular self-assembly islands coexist obtained in step 4 to obtain large-area Sb4 molecular self-assembly islands; the growth temperature is 150 DEG C, and the temperature keeping time is 30 min.

[0055] Embodiment 3

[0056] The preparation method of the large-area Sb4 molecular self-assembly structure includes the following specific steps:

[0057] Step 1, preparing a gold single crystal substrate; the preparation process of the gold single crystal substrate is specifically as follows:

[0058] Step 1.1. Argon ion sputtering treatment was performed on a gold substrate in an ultra-high vacuum chamber to obtain a gold substrate;

[0059] Step 1.2. The gold substrate obtained in step 1.1 was heated to 450℃ and kept for 30 min to obtain a gold single crystal substrate;

[0060] Step 2. 100 mg of antimony powder was evaporated and deposited on the 50 g gold single crystal substrate obtained in step 1 using a thermal resistance K-cell molecular evaporation source at an evaporation temperature of 230℃ to obtain a substrate and Sb4 molecular self-assembly chains deposited on the substrate. The deposition process controlled the temperature of the Sb4 molecular self-assembly chains and the gold single crystal substrate on the substrate to be 30℃, and the deposition time was 5-10 min;

[0061] Step 3. The substrate and Sb4 molecular self-assembly chains deposited on the substrate obtained in step 2 were subjected to a first temperature rise to the growth temperature for heat preservation treatment to obtain a small-area Sb4 molecular self-assembly island. The growth temperature was 100℃, and the heat preservation time was 30 min;

[0062] Step 4. Then 400 mg of antimony powder was evaporated and deposited on the 50 g substrate and Sb4 molecular self-assembly island treated in step 3 using a thermal resistance K-cell molecular evaporation source at an evaporation temperature of 230℃ to obtain a gold substrate with coexistence of Sb4 molecular self-assembly chains and small-area Sb4 molecular self-assembly islands. The deposition process controlled the temperature of the substrate and the deposited material to be 30℃, and the deposition time was 20-30 min;

[0063] Step 5. The Sb4 molecular self-assembly chains and small-area Sb4 molecular self-assembly islands coexisting gold substrate obtained in step 4 was subjected to a second temperature rise to the growth temperature for heat preservation treatment to obtain a large-area Sb4 molecular self-assembly island. The growth temperature was 150℃, and the heat preservation time was 30 min.

[0064] The specific embodiments of the application are described in detail above in conjunction with the accompanying drawings, but the application is not limited to the above-described embodiments. Within the knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the application.

Claims

1. A method for preparing Sb4 self-assembled structures, characterized in that The specific steps include: Step 1, preparing a gold single crystal substrate; Step 2, evaporating and depositing antimony powder on the gold single crystal substrate of step 1 to obtain a substrate and Sb4 self-assembled chains deposited on the substrate, and the deposition process controls the temperature of the gold single crystal substrate to be 25-30℃; Step 3, the substrate and Sb4 self-assembled chains deposited on the substrate of step 2 are subjected to a first temperature rise to the growth temperature for heat preservation treatment, obtaining a gold single crystal substrate with small-area Sb4 self-assembled islands; Step 4, then evaporate and deposit antimony powder on the gold single crystal substrate with small-area Sb4 self-assembled islands and gold single crystal substrate treated in step 3 to obtain a gold single crystal substrate with coexistence of small-area Sb4 molecular self-assembled islands and Sb4 molecular self-assembled chains, and the deposition process controls the substrate temperature to be 25-30℃; Step 5, the gold single crystal substrate with coexistence of small-area Sb4 molecular self-assembled islands and Sb4 molecular self-assembled chains obtained in step 4 is subjected to a second temperature rise to the growth temperature for heat preservation treatment to obtain a gold single crystal substrate with large-area Sb4 molecular self-assembled islands; The evaporation temperature of antimony powder in step 2 is 230-235℃, and the deposition time is 5-10min; The growth temperature in step 3 is 100℃, and the heat preservation time is 30min; The evaporation temperature of antimony powder in step 4 is 230-235℃, and the deposition time is 20-30min; The growth temperature in step 5 is 150℃, and the heat preservation time is 30min.

2. The method of claim 1, wherein: The preparation process of the gold single crystal substrate is as follows: Step 2.1, in an ultra-high vacuum cavity, argon ion sputtering treatment is performed on the gold substrate to obtain a gold substrate; Step 2.2, heat the gold substrate obtained in step 2.1 to 450℃ and keep for 10-30min to obtain a gold single crystal substrate.

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