Purple phosphorus micron tube array and preparation method thereof

Abstract

The invention discloses a purple phosphorus micron tube array and a preparation method thereof. The purple phosphorus micro-tube array has unique structural characteristics, the diameter of a micro-tube is 1-10 [mu] m, the aperture is 0.3-1.7 [mu] m, and the tube length is 10-500 [mu] m. The preparation method comprises the following steps: mixing amorphous red phosphorus (the purity is 99.99%-99.9999%) and iodine elementary substance (the purity is 99.8%-99.99%) according to the mass ratio of 15: 1-25: 1, sealing the mixture in a quartz tube under the vacuum condition of 10 <-4 >-10 <-5 > Pa, and carrying out gradient temperature control through a horizontal double-temperature-zone tubular furnace: heating a medicine zone to 470-520 DEG C at a speed of 2-5 DEG C / min and carrying out heat preservation for 20-25 hours, and synchronously heating a non-medicine zone to 450-460 DEG C; the inclined angle design of 5-60 degrees of the quartz tube is combined with the synergistic effect of double temperature zones, and directional growth of Hittorf purple phosphorus microcrystals is realized through an iodine steam transport mechanism. The method is simplified in process and low in cost, the high-purity purple phosphorus micron tube array is obtained, the band gap is about 1.90 eV, the method can be used for field effect transistors, photoelectric detectors, photo-thermal conversion, photocatalysis and electro-catalysis, and a novel structure semiconductor material is provided for the field of photoelectric devices.

Description

Technical Field

[0001] The present invention relates to a purple phosphorus microtube array and a preparation method thereof, which has important application prospects in electronics, optoelectronics, photocatalysis, and electrochemical energy storage, and belongs to the field of inorganic crystal materials and the technical field of optical, electrical and energy storage material preparation. Background Art

[0002] Purple phosphorus is a phosphorus allotrope with a unique crystal structure and excellent physical and chemical properties. Due to its band gap of approximately 1.90 eV and its excellent optical, electrical, and catalytic properties, purple phosphorus has become a research hotspot in photodetectors, field-effect transistors, photothermal conversion, photocatalysis, electrocatalysis, and energy storage (such as alkali metal ion batteries and supercapacitors). Compared to other phosphorus allotropes (such as black phosphorus), purple phosphorus offers significant advantages in stability, optoelectronic properties, and controllable preparation, thus holding broad application prospects in modern electronic devices and energy technologies.

[0003] Purple phosphorus has two structures: Hittorf purple phosphorus with a P2 / c space group and monoclinic P2 / n purple phosphorus, developed by Professor Zhang Jinying of Xi'an Jiaotong University (L. Zhang, H. Huang, B. Zhang, et al. AngewandteChemie International Edition, German Journal of Applied Chemistry, 2020, Vol. 59, 1074). Currently, the main methods for preparing Hittorf and monoclinic P2 / n purple phosphorus include solvent methods, chemical vapor deposition, and vapor transport methods. The vapor transport method, due to its simplicity, low cost, and scalability, has become a major approach for preparing high-quality purple phosphorus materials. However, there are few reports on the controlled synthesis of Hittorf purple phosphorus. The few existing methods for synthesizing Hittorf purple phosphorus use amorphous red phosphorus with Sn / I2 or amorphous red phosphorus with Sn+SnI4 systems, involving numerous chemical reagents, low product purity, uncontrollable morphology, and complex preparation conditions, limiting their widespread application in practical applications. Therefore, developing an efficient, low-cost and highly controllable method for preparing purple phosphorus, especially a method for preparing Hittorf purple phosphorus microtube arrays with regular morphology, has important scientific significance and application value. Summary of the Invention

[0004] The object of the present invention is to provide a purple phosphorus microtube array, characterized in that, in the purple phosphorus microtube array, the diameter of the microtubes ranges from 1 to 10 μm, the pore size of the microtubes ranges from 0.3 to 1.7 μm, and the tube length ranges from 10 to 500 μm.

[0005] Another object of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a purple phosphorus microtube array, which can simply use only two raw materials, amorphous red phosphorus and iodine, to prepare purple phosphorus with a microtube array structure through iodine vapor transport.

[0006] The present invention provides a method for preparing a purple phosphorus microtube array, comprising the following steps:

[0007] (1) High-purity amorphous red phosphorus with a purity of 99.99%-99.9999% and iodine with a purity of 99.8%-99.99% were placed in a quartz glass tube at a mass ratio of 15:1-25:1, and a vacuum tube sealing machine was used for 10 -4 -10 -5 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa to ensure that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube;

[0008] (2) Place a quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal dual-zone tube furnace, with both ends of the quartz tube located in the heating zone of the dual-zone tube furnace, and raise the side of the quartz tube without the chemical to form an inclination angle of 5-60° with the direction of the tube furnace;

[0009] (3) The temperature of the dual temperature zones is programmed to rise: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) is set to rise from room temperature to 470-520°C at a heating rate of 2-5°C / min, keep warm for 20-25 hours, and then cool to room temperature at a cooling rate of 1-5°C / min; the temperature of the side without drugs is set to rise from room temperature to 450-460°C at the same heating time as the drug zone, keep warm for the same time as the drug zone, and then cool to room temperature at the same cooling time as the drug zone;

[0010] (4) After the reaction is completed, the quartz glass tube is broken and the flaky product on the tube wall is peeled off with tweezers to obtain a curved thin flaky product, which is the crystalline Hittorf purple phosphorus microtube array. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a scanning electron microscope image of the Hittorf purple phosphorus microtube array in Example 2;

[0012] Figure 2 is the X-ray diffraction pattern of the Hittorf purple phosphorus microtube array in Example 2;

[0013] Figure 3 This is the Raman spectrum of the Hittorf purple phosphorus microtube array in Example 2;

[0014] Figure 4This is the energy-absorption curve obtained by the Tauc plot method of the plate-like crystalline purple phosphorus in Example 2. DETAILED DESCRIPTION Example 1

[0015] The following is a further description of the present invention, but does not limit the scope of the present invention.

[0016] (1) High-purity amorphous red phosphorus with a purity of 99.99% and iodine with a purity of 99.8% were placed in a quartz glass tube at a mass ratio of 150 mg:10 mg, and a vacuum tube sealing machine was used for 10 -4 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa, ensuring that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube.

[0017] (2) Place the quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal dual-zone tube furnace. The two ends of the quartz tube are located in the heating zone of the dual-zone tube furnace. The side of the quartz tube without the chemical is raised to form a 5° inclination angle with the direction of the tube furnace.

[0018] (3) The temperature of the dual temperature zones was programmed to rise: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) was set to rise from room temperature to 470°C at a heating rate of 2°C / min, kept at this temperature for 20 hours, and then cooled to room temperature at a cooling rate of 1°C / min; the temperature of the side without drugs was set to rise from room temperature to 450°C at the same heating time as the drug zone, kept at this temperature for the same time as the drug zone, and then cooled to room temperature at the same cooling time as the drug zone.

[0019] (4) After the reaction is completed, the quartz glass tube is broken and the curved plate-like crystal product on the tube wall is peeled off with tweezers to obtain a crystalline Hittorf purple phosphorus microtube array. Example 2

[0020] (1) High-purity amorphous red phosphorus with a purity of 99.999% and iodine with a purity of 99.9% were placed in a quartz glass tube at a mass ratio of 200 mg:10 mg, and a vacuum tube sealing machine was used for 10 -5 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa, ensuring that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube.

[0021] (2) Place the quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal double-temperature zone tube furnace. The two ends of the quartz tube are located in the heating zone of the double-temperature zone tube furnace. The side of the quartz tube without the chemical is raised to form a 45° inclination angle with the direction of the tube furnace.

[0022] (3) The temperature of the dual temperature zones was programmed to rise: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) was set to rise from room temperature to 480°C at a heating rate of 2.5°C / min, kept at this temperature for 20 hours, and then cooled to room temperature at a cooling rate of 2°C / min; the temperature of the side without drugs was set to rise from room temperature to 450°C at the same heating time as the drug zone, kept at this temperature for the same time as the drug zone, and then cooled to room temperature at the same cooling time as the drug zone.

[0023] (4) After the reaction is completed, the quartz glass tube is broken and the curved plate-like crystal product on the tube wall is peeled off with tweezers. Scanning electron microscopy shows that the plate-like crystals are composed of micron tube arrays. Through size measurement statistics, the diameter range of the micron tubes is 1-10μm, the pore size of the micron tubes is 0.3-1.7μm, and the tube length is 10-500μm. Figure 1 As shown; Figure 2 X-ray diffraction tests confirmed that the crystal structure of the prepared microtube array was consistent with the standard PDF card of Hittorf purple phosphorus, proving that the amorphous red phosphorus raw material formed the Hittorf purple phosphorus crystal structure after gas phase transport. Figure 3 The Raman spectrum of the obtained flake product is shown, indicating that the −1 、387cm −1 、398cm −1 、418cm −1 、460cm −1 There are five characteristic peaks at the bottom of the crystal, which are caused by the bending and stretching vibrations of the chemical bonds of Hittorf purple phosphorus, proving that the product is high-quality Hittorf purple phosphorus crystals. Figure 4 The optical absorption test combined with the curve obtained by the Tauc plot method and the calculated results show that the band gap of the prepared purple phosphorus microtube array is about 1.90 eV. Example 3

[0024] (1) High-purity amorphous red phosphorus with a purity of 99.9999% and iodine with a purity of 99.99% were placed in a quartz glass tube at a mass ratio of 250 mg:10 mg, and a vacuum tube sealing machine was used for 10 -5 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa, ensuring that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube.

[0025] (2) Place the quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal dual-temperature zone tube furnace. The two ends of the quartz tube are located in the heating zone of the dual-temperature zone tube furnace. The side of the quartz tube without the chemical is raised to form a 60° inclination angle with the direction of the tube furnace.

[0026] (3) The temperature of the dual temperature zones was programmed to rise: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) was set to rise from room temperature to 500°C at a heating rate of 2.5°C / min, kept at this temperature for 22 hours, and then cooled to room temperature at a cooling rate of 3°C / min; the temperature of the side without drugs was set to rise from room temperature to 460°C at the same heating time as the drug zone, kept at this temperature for the same time as the drug zone, and then cooled to room temperature at the same cooling time as the drug zone.

[0027] (4) After the reaction is completed, the quartz glass tube is broken and the curved plate-like crystal product on the tube wall is peeled off with tweezers to obtain a crystalline Hittorf purple phosphorus microtube array. Example 4

[0028] (1) High-purity amorphous red phosphorus with a purity of 99.9999% and iodine with a purity of 99.99% were placed in a quartz glass tube at a mass ratio of 250 mg:10 mg, and a vacuum tube sealing machine was used for 10 -5 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa, ensuring that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube.

[0029] (2) Place the quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal dual-temperature zone tube furnace. The two ends of the quartz tube are located in the heating zone of the dual-temperature zone tube furnace. The side of the quartz tube without the chemical is raised to form a 60° inclination angle with the direction of the tube furnace.

[0030] (3) The temperature of the dual temperature zones was programmed to rise: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) was set to rise from room temperature to 520°C at a heating rate of 5°C / min, kept at this temperature for 25 hours, and then cooled to room temperature at a cooling rate of 5°C / min; the temperature of the side without drugs was set to rise from room temperature to 460°C at the same heating time as the drug zone, kept at this temperature for the same time as the drug zone, and then cooled to room temperature at the same cooling time as the drug zone.

[0031] (4) After the reaction is completed, the quartz glass tube is broken and the curved plate-like crystal product on the tube wall is peeled off with tweezers to obtain a crystalline Hittorf purple phosphorus microtube array.

[0032] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A purple phosphorus microtube array, characterized in that: The purple phosphorus microtube array is composed of Hittorf purple phosphorus microtubes grown by vapor transport. The diameter of the microtubes ranges from 1 to 10 μm, the pore size of the microtubes ranges from 0.3 to 1.7 μm, and the tube length ranges from 10 to 500 μm.

2. The method for preparing a purple phosphorus microtube array according to claim 1, wherein: The following steps are involved: (1) High-purity amorphous red phosphorus with a purity of 99.99%-99.9999% and iodine with a purity of 99.8%-99.99% were placed in a quartz glass tube at a mass ratio of 15:1-25:1, and a vacuum tube sealing machine was used for 10 -4 -10 -5 The quartz glass tube is sealed under a vacuum condition of 1.5 Pa to ensure that amorphous red phosphorus and iodine are concentrated on one side of the bottom of the quartz glass tube; (2) Place the quartz glass tube sealed with amorphous red phosphorus and iodine in a horizontal dual-temperature zone tube furnace, with both ends of the quartz tube located in the heating zone of the dual-temperature zone tube furnace, and raise the side of the quartz tube without the chemical so that it forms an inclination angle of 5-60° with the direction of the tube furnace; (3) The temperature of the dual temperature zones is set to rise and fall respectively: the temperature of the side containing amorphous red phosphorus and iodine (drug zone) is set to rise from room temperature to 470-520°C at a heating rate of 2-5°C / min, keep warm for 20-25 hours, and then cool to room temperature at a cooling rate of 1-5°C / min; the temperature of the side without drugs is set to rise from room temperature to 450-460°C at the same heating time as the drug zone, keep warm for the same time as the drug zone, and then cool to room temperature at the same cooling time as the drug zone; (4) After the reaction is completed, the quartz glass tube is broken and the flaky product on the tube wall is peeled off with tweezers to obtain a curved thin flaky product, which is the crystalline Hittorf purple phosphorus microtube array.

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