Preparation method of silicon-doped black phosphorus

Abstract

This invention discloses a method for preparing silicon-doped black phosphorus, comprising: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... ‑4 Below the required pressure (Tor), silicon-containing gas, phosphorus-containing gas, and inert protective gas are introduced into the plasma vapor deposition equipment until the internal pressure reaches 100–1000 Pa. Then, the temperature is raised to 200–1000 °C within 1–60 minutes, and black phosphorus is bombarded at a radio frequency power of 5–600 W for 1–360 minutes. Afterward, the temperature is cooled to room temperature, thus producing silicon-doped black phosphorus. This invention dops silicon into black phosphorus without damaging its physicochemical properties. Furthermore, the process is simple, the product quality is high, and the product can be widely used in electrochemical energy storage and electronic communications.

Description

Technical Field

[0001] This invention relates to the field of black phosphorus composite materials, and more particularly to a method for preparing silicon-doped black phosphorus. Background Technology

[0002] Black phosphorus is a two-dimensional phosphorus material. Its unique curved layered structure, electronic and elemental properties endow it with excellent electrochemical, thermal conductivity, and flame-retardant properties, making it a promising candidate for applications in electrochemical energy storage, electronic communications, and flame-retardant materials. However, black phosphorus exhibits high chemical reactivity; phosphorus atoms readily react with oxygen, water, and other substances to generate a series of oxidation products, thereby losing its original structure and properties. Therefore, strict protection measures are essential when using black phosphorus materials; otherwise, they will rapidly lose their performance due to water and oxygen corrosion. For example, doping techniques can be used to introduce silicon atoms into black phosphorus materials to improve its electronic properties and reduce its reactivity.

[0003] Black phosphorus's unique structure makes it widely applicable as an electrode material in lithium-ion and sodium-ion batteries; however, its severe structural expansion during charge and discharge significantly limits its application. Besides black phosphorus, silicon also exhibits good performance in ion batteries, and related compounds such as silicon carbide and silicon oxide are widely used. Therefore, atomically combining silicon with black phosphorus will allow both materials to exert their respective advantages, further improving the capacity of ion batteries while simultaneously modifying black phosphorus through doping.

[0004] In existing technologies, there is no fundamental solution to the environmental instability of black phosphorus, namely its susceptibility to oxidation and corrosion. Furthermore, the structural expansion problem of black phosphorus as an electrode material during the charging and discharging process of ion batteries has not been well controlled. Additionally, there are currently no silicon-doped black phosphorus materials or their synthesis methods. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing silicon-doped black phosphorus. This method incorporates silicon into black phosphorus, giving it excellent environmental stability, resistance to expansion, and high flame retardancy. Not only are the physicochemical properties of black phosphorus not compromised, but the process is also simple, requires minimal equipment, and produces high-quality products. The product can be widely used in electrochemical energy storage and electronic communications.

[0006] In a first aspect, the present invention provides a method for preparing silicon-doped black phosphorus, comprising the following steps:

[0007] 1) Place the black phosphorus in a plasma vapor deposition apparatus and evacuate the apparatus;

[0008] 2) Fill the plasma vapor deposition equipment with silicon-containing gas, phosphorus-containing gas and inert protective gas until the internal pressure of the plasma vapor deposition equipment is 100-1000 Pa;

[0009] 3) The black phosphorus is heated and bombarded for a period of time, then cooled to room temperature to obtain silicon-doped black phosphorus. In some embodiments, in step 1), the equipment is evacuated to 10... -4 torr below.

[0010] In some embodiments, in step 2), the silicon-containing gas is selected from at least one of hydrogen silicide, silicon tetrafluoride, trichlorosilane, silicon tetrachloride, and dichlorosilane.

[0011] And / or, the phosphorus-containing gas is selected from at least one of phosphorus trichloride, phosphorus pentafluoride and phosphine;

[0012] And / or, the inert protective gas is selected from at least one of helium, argon, and nitrogen.

[0013] In some implementations, in step 2), the flow rate of the gas introduced into the plasma vapor deposition apparatus is 5 to 100 sccm, preferably 10 to 60 sccm.

[0014] And / or, the volume percentage of silicon-containing gas is 1-90%, preferably 5-25%;

[0015] And / or, the internal pressure of the plasma vapor deposition equipment is 100–500 Pa.

[0016] In some implementations, in step 3), the temperature is raised to 200-1000°C within 1-60 minutes, preferably to 200-550°C within 30-60 minutes;

[0017] And / or, the black phosphorus is bombarded at a radio frequency power of 5-600W for 1-360 minutes, preferably at a radio frequency power of 50-600W, and preferably for a bombardment time of 60-360 minutes. In a second aspect, the present invention provides silicon-doped black phosphorus prepared by the above-described preparation method.

[0018] Third party, this invention provides the application of silicon-doped black phosphorus prepared by the above preparation method in the preparation of battery materials.

[0019] In some embodiments, the application is in the preparation of electrode materials, preferably in the preparation of electrode materials for lithium-ion batteries.

[0020] Beneficial effects

[0021] The method for preparing silicon-doped black phosphorus provided by this invention involves placing black phosphorus in a plasma vapor deposition apparatus. A radio frequency (RF) power supply is used to continuously ionize silicon-containing and phosphorus-containing gases within the apparatus, treating the surface of the black phosphorus. Simultaneously, the reaction temperature, internal pressure of the apparatus, RF power, and processing time are controlled to dope silicon into the black phosphorus, forming silicon-doped black phosphorus. The addition of a small amount of silicon atoms allows the unique physicochemical properties of black phosphorus to be preserved, maintaining its excellent electrical conductivity, thermal conductivity, stability, and flame retardancy. Furthermore, when silicon-doped black phosphorus is used in lithium-ion batteries, the addition of silicon atoms can further improve the specific capacity of the lithium battery. The method for preparing silicon-doped black phosphorus provided by this invention not only preserves the physicochemical properties of black phosphorus but also offers simple operation, high product quality, and wide applicability in electrochemical energy storage and electronic communications. Attached Figure Description

[0022] Figure 1 Scanning electron microscope image of silicon-doped black phosphorus. Detailed Implementation

[0023] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0024] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0025] Example 1

[0026] A method for preparing silicon-doped black phosphorus includes the following steps: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... -4 Below torr, hydrogen silicide (5% by volume), phosphine (5% by volume), and helium (90% by volume) are then introduced into the plasma vapor deposition apparatus at a flow rate of 10 sccm until the internal pressure of the apparatus reaches 100 Pa. The temperature is then raised to 200°C over 60 minutes, and black phosphorus is bombarded at a radio frequency power of 50 W for 360 minutes. Afterward, the temperature is cooled to room temperature, thus producing the desired product. Figure 1 The image shows silicon-doped black phosphorus. Elemental analysis revealed a silicon atomic percentage of 0.63%. When silicon-doped black phosphorus was used as an electrode material in a lithium-ion battery, the battery achieved a discharge specific capacity of 1715 mAh / g after 100 charge-discharge cycles, which is higher than that of a battery composed of black phosphorus and metallic lithium (1510 mAh / g).

[0027] Example 2

[0028] A method for preparing silicon-doped black phosphorus includes the following steps: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... -4 Below the required temperature (Tr), silicon tetrafluoride gas (15% by volume), phosphorus trichloride gas (5% by volume), and argon gas (80% by volume) are introduced into the ion vapor deposition apparatus at a flow rate of 15 sccm until the internal pressure of the apparatus reaches 250 Pa. The temperature is then raised to 300 °C over 45 min, and black phosphorus is bombarded at 150 W RF power for 300 min, followed by cooling to room temperature, thus producing silicon-doped black phosphorus. Elemental analysis revealed a silicon atomic percentage of 0.61%. When silicon-doped black phosphorus is used as an electrode material in lithium-ion batteries, the battery exhibits a discharge specific capacity of 1722 mAh / g after 100 charge-discharge cycles, higher than that of a battery composed of black phosphorus and lithium metal (1510 mAh / g).

[0029] Example 3

[0030] A method for preparing silicon-doped black phosphorus includes the following steps: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... -4 Below the tor, trichlorosilane gas (20% by volume), phosphorus pentafluoride gas (10% by volume), and argon gas (70% by volume) were introduced into the ion vapor deposition equipment at a flow rate of 20 sccm until the internal pressure of the ion vapor deposition equipment reached 350 Pa. Then, the temperature was raised to 400 °C within 30 min, and black phosphorus was bombarded at a radio frequency power of 250 W for 240 min, followed by cooling to room temperature, thus obtaining silicon-doped black phosphorus. Elemental analysis revealed a silicon atomic percentage of 0.64%. When silicon-doped black phosphorus was used as an electrode material in lithium-ion batteries, the specific discharge capacity after 100 charge-discharge cycles was tested to be 1699 mAh / g, higher than that of batteries composed of black phosphorus and metallic lithium (1510 mAh / g).

[0031] Example 4

[0032] A method for preparing silicon-doped black phosphorus includes the following steps: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... -4Below the tor, trichlorosilane gas (10% by volume), dichlorosilane gas (10% by volume), phosphine gas (5% by volume), and argon gas (75% by volume) were introduced into the plasma vapor deposition equipment at a flow rate of 40 sccm until the internal pressure of the plasma vapor deposition equipment reached 500 Pa. Then, the temperature was raised to 500 °C within 30 min, and black phosphorus was bombarded at a radio frequency power of 400 W for 120 min, followed by cooling to room temperature, thus obtaining silicon-doped black phosphorus. Elemental analysis showed that the silicon atomic percentage was 0.59%. When silicon-doped black phosphorus was used as an electrode material in lithium-ion batteries, the specific discharge capacity after 100 charge-discharge cycles was tested to be 1711 mAh / g, higher than that of batteries composed of black phosphorus and metallic lithium (1510 mAh / g).

[0033] Example 5

[0034] A method for preparing silicon-doped black phosphorus includes the following steps: placing black phosphorus in a plasma vapor deposition apparatus and evacuating to a vacuum of 10... -4 Below the tor, hydrogen silicide (25% by volume), phosphine (5% by volume), phosphorus pentafluoride (5% by volume), and argon (65% by volume) were introduced into the plasma vapor deposition equipment at a flow rate of 60 sccm until the internal pressure of the equipment reached 400 Pa. The temperature was then raised to 550 °C over 40 minutes, and black phosphorus was bombarded at a radio frequency power of 600 W for 60 minutes, followed by cooling to room temperature, thus producing silicon-doped black phosphorus. Elemental analysis revealed a silicon atomic percentage of 0.62%. When silicon-doped black phosphorus was used as an electrode material in lithium-ion batteries, the battery exhibited a discharge specific capacity of 1717 mAh / g after 100 charge-discharge cycles, higher than that of a battery composed of black phosphorus and metallic lithium (1510 mAh / g).

[0035] In summary, the embodiments of the present invention can dope silicon into black phosphorus to obtain silicon-doped black phosphorus material. The addition of a small number of silicon atoms in this material not only does not damage the physicochemical properties of black phosphorus, but also makes the operation simple and the product can be widely used in electrochemical energy storage and electronic communication fields.

[0036] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing silicon-doped black phosphorus, comprising the following steps: 1) Place the black phosphorus in a plasma vapor deposition apparatus and evacuate the apparatus; 2) Fill the plasma vapor deposition equipment with silicon-containing gas, phosphorus-containing gas, and inert protective gas until the internal pressure of the plasma vapor deposition equipment is 100-1000 Pa; 3) Heat the black phosphorus to 200-400℃ within 1-60 minutes and bombard it, then cool it to room temperature to obtain silicon-doped black phosphorus.

2. The preparation method according to claim 1, characterized in that, In step 1), the equipment is evacuated to 10... -4 torr below.

3. The preparation method according to claim 1, characterized in that, In step 2), the silicon-containing gas is selected from at least one of hydrogen silicide, silicon tetrafluoride, trichlorosilane, silicon tetrachloride, and dichlorosilane. And / or, the phosphorus-containing gas is selected from at least one of phosphorus trichloride, phosphorus pentafluoride and phosphine; And / or, the inert protective gas is selected from at least one of helium, argon, and nitrogen.

4. The preparation method according to any one of claims 1-3, characterized in that, In step 2), the flow rate of the gas introduced into the plasma vapor deposition equipment is 5–100 sccm; And / or, the volume percentage of silicon-containing gas is 1-90%; And / or, the internal pressure of the plasma vapor deposition equipment is 100–500 Pa.

5. The preparation method according to claim 4, characterized in that, In step 2), the flow rate of the gas introduced into the plasma vapor deposition equipment is 10–60 sccm; And / or, the volume percentage of silicon-containing gas is 5-25%.

6. The preparation method according to any one of claims 1-3, characterized in that, In step 3), black phosphorus is bombarded with radio frequency power of 5-600W for 1-360 minutes.

7. The preparation method according to claim 6, characterized in that, In step 3), the radio frequency power is 50-600W; And / or, the bombardment treatment time for black phosphorus is 60–360 min.

8. Silicon-doped black phosphorus prepared by the preparation method according to any one of claims 1-7.

9. The application of silicon-doped black phosphorus prepared by the preparation method according to any one of claims 1-7 in the preparation of electrode materials for lithium-ion batteries.

Images