CN110511748A - A kind of preparation method of fluorescent boron carbide nanobelt - Google Patents

Abstract

The invention discloses a method for preparing a fluorescent boron carbide nanobelt, using nickel oxide or nickel nitrate powder, boron powder, silicon dioxide powder and boron trioxide powder with a purity of not less than 98% as raw materials, according to the reaction equation 2xNiO +xSiO ₂ +(4x+2y)B+2yB ₂ O ₃ ＝xNi ₂ Si+(2x+3y)B ₂ O ₂ , weigh 0.01<x/y<0.15, mix the weighed raw materials evenly in anhydrous In ethanol, heat and stir until dry; put the dried mixture in a graphite crucible with a cover, put it into a high-temperature tube furnace, conduct heat treatment under an inert protective atmosphere, and collect it on the graphite crucible wall and cover after cooling down with the furnace The off-white fluffy powder is fluorescent boron carbide nanoribbons. The invention has the advantages of simple and easy-to-obtain raw materials, simple and controllable operation, good repeatability, high sample purity and the like.

Description

A kind of preparation method of fluorescent boron carbide nanobelt

technical field

The invention belongs to the technical field of preparation of LED fluorescent powder and nanometer materials, and in particular relates to a method for preparing fluorescent boron carbide nanobelts.

Background technique

In 2001, Professor Wang Zhonglin of the Georgia Institute of Technology and others discovered and synthesized semiconductor oxides with a nanoribbon structure for the first time in the world, which was another major breakthrough in the field of nanomaterial synthesis. Professor Wang Zhonglin and others successfully synthesized band structures of broadband semiconductor systems such as zinc oxide, tin oxide, indium oxide, cadmium oxide, and gallium oxide by high-temperature solid gas phase method. These ribbon structures have high purity, large yield, complete structure, clean surface, and no defects or dislocations inside. They are ideal single-crystal linear thin-sheet structures, which have attracted widespread attention.

Boron carbide is widely used in extreme environments such as high temperature and high pressure because of its good mechanical properties, heat resistance, high temperature resistance, and corrosion resistance. Due to its strong quantum size effect, one-dimensional boron carbide often exhibits better mechanical, optical, and electrical properties than traditional bulk materials. It also has good application prospects in the construction of nano-devices and has received great attention. . Using density functional theory (DFT) based on first principles, Sun et al. first carried out a theoretical study on one-dimensional silicon carbide nanoribbons, zigzag silicon carbide nanoribbons and armchair-shaped silicon carbide nanoribbons passivated with hydrogen at the edges The structure, properties and stability of silicon carbide nanobelts were studied. The results show that the armrest-shaped SiC nanoribbons are non-magnetic and semiconducting, while the zigzag SiC nanoribbons exhibit magnetic metallic or semiconducting properties due to different strip widths. Studies have shown that the electromagnetic properties of silicon carbide nanoribbons can be tuned by doping. For example, zigzag silicon carbide nanobelts with single boron or nitrogen atoms replacing designated atoms can achieve 100% spin polarization and obtain half-metallic properties. When the doping position of boron or nitrogen atoms is changed, the system can be transformed from ferromagnetic state to ferrimagnetic state, and interesting properties such as metal, semimetal and semiconductor behavior can be obtained. However, there are still few reports on the preparation of boron carbide nanobelts at home and abroad. Xu et al. used B ₂ O ₃ and graphite sieve as raw materials, and obtained boron carbide on BN substrate after heating to 1950°C in a high-frequency induction furnace. Nanobelts (J.Phys.Chem.B, 2004, 108, 7651-7655.); Bao et al. used B ₂ O ₃ powder, boron powder, carbon powder and iron powder to form a silicon substrate by two-step chemical vapor deposition. On-chip boron carbide nanobelts were obtained (Chinese Physics B, 2008, 17, 11, 4247-4252.). The preparation methods reported so far are relatively complicated, have high requirements for equipment, and poor repeatability, and the number of boron carbide nanobelts prepared is small and the purity is low, which is not conducive to further research and utilization. Therefore, the development of a new type is simple and effective. The preparation method of boron carbide nanobelts is of great significance.

Contents of the invention

The purpose of the present invention is to provide a method for preparing fluorescent boron carbide nanobelts with simple preparation process, high yield and high sample purity.

The preparation method of the fluorescent boron carbide nanobelt of the present invention is: using nickel oxide or nickel nitrate powder, boron powder, silicon dioxide powder and boron trioxide powder as raw materials, according to the reaction equation 2xNiO+xSiO ₂ +(4x+2y) B+2yB ₂ O ₃ ＝xNi ₂ Si+(2x+3y)B ₂ O ₂ , where 0.01≤x/y≤0.15, the raw materials are weighed according to the molar ratio, and the weighed raw materials are evenly mixed in absolute ethanol, Heat and stir until dry; then put the dried mixture in a graphite crucible with a cover, put it into a high-temperature tube furnace, heat it to 1350-1600°C under an inert protective atmosphere, heat it for 1-5 hours, and cool it down with the furnace Collect off-white fluffy powder on the wall and cover of the graphite crucible to obtain fluorescent boron carbide nanobelts.

The purity of the above-mentioned nickel oxide or nickel nitrate powder, boron powder, diboron trioxide powder and silicon dioxide powder is not less than 98%.

In the above preparation method, preferably 0.05≤x/y≤0.1.

In the above preparation method, the weighed raw materials are uniformly mixed in absolute ethanol, heated and stirred at 50-90° C. until dry.

In the above preparation method, it is preferred to heat to 1400-1500° C. under an inert protective atmosphere, and heat-treat for 1-3 hours.

In the above preparation method, the inert protective atmosphere is an argon atmosphere with a flow rate of 80-200mL/min.

In the present invention, nickel oxide or nickel nitrate powder, boron powder, silicon dioxide powder and boron trioxide powder are used as raw materials, and the raw materials are heat-treated at high temperature in a graphite crucible, and the off-white fluffy powder is collected on the graphite crucible wall and cover. Fluorescent boron carbide nanoribbons. The beneficial effects of the present invention are as follows:

1. The raw materials used in the present invention are cheap and easy to obtain, the preparation process is simple, the repeatability is good, and it is easy to realize.

2. The fluorescent boron carbide nanobelt prepared by the present invention has good crystallinity, high purity, regular shape and uniform size.

3. The fluorescent boron carbide nanobelts prepared in the present invention have good luminescent properties.

Description of drawings

Fig. 1 is the Raman spectrum of the fluorescent boron carbide nanobelt prepared in Example 1.

Fig. 2 is the SEM image of the fluorescent boron carbide nanobelt prepared in Example 1.

Fig. 3 is the PL spectrum of the fluorescent boron carbide nanobelt prepared in Example 1.

Fig. 4 is the SEM image of the fluorescent boron carbide nanobelt prepared in Example 2.

Fig. 5 is the PL spectrum of the fluorescent boron carbide nanobelt prepared in Example 2.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments, but the protection scope of the present invention is not limited to these embodiments.

Example 1

0.0747g (1mmol) nickel oxide with a purity greater than 98%, 0.1297g (12mmol) boron powder with a purity greater than 98%, 0.0300g (0.5mmol) silica powder with a purity greater than 98%, 0.6960g (10mmol) with a purity greater than 98% Add 98% boron trioxide powder to 20 mL of absolute ethanol in turn, heat and stir in a water bath at 90°C until dry. Put the dried mixed powder in a graphite crucible with a cover, place the graphite crucible in a high-temperature tube furnace, heat it to 1500°C in an argon atmosphere with a flow rate of 120mL/min, and heat it at a constant temperature for 1 hour. After cooling down, off-white fluffy powder is collected on the graphite crucible wall and cover to obtain fluorescent boron carbide nanobelts. As can be seen from Figure 1, the resulting product is boron carbide. It can be seen from Fig. 2 that the obtained boron carbide nanoribbons have a width of 1-3 μm, a length of tens to hundreds of microns, and uniform distribution. It can be seen from Fig. 3 that the excitation spectrum of the obtained boron carbide nanobelt covers 400-500 nm, and the emission peak is located at 436 nm, indicating that the material can emit ultraviolet light.

Example 2

0.0896g (1.2mmol) nickel oxide with a purity greater than 98%, 0.1340g (12.4mmol) boron powder with a purity greater than 98%, 0.0360g (0.6mmol) silica powder with a purity greater than 98%, 0.6960g (10mmol) Diboron trioxide powder with a purity greater than 98% was sequentially added to 15 mL of absolute ethanol, heated and stirred in a water bath at 70° C. until dry. Put the dried mixed powder in a graphite crucible with a cover, place the graphite crucible in a high-temperature tube furnace, heat it to 1500°C in an argon atmosphere with a flow rate of 120mL/min, and heat it at a constant temperature for 1 hour. After cooling down, off-white fluffy powder is collected on the graphite crucible wall and cover to obtain fluorescent boron carbide nanobelts. It can be seen from FIG. 4 that the obtained fluorescent boron carbide nanoribbons have a width of 1-10 μm, a length of 50 μm to hundreds of microns, and uniform distribution. It can be seen from Fig. 5 that the excitation spectrum of the obtained boron carbide nanobelt covers 400-500 nm, and the emission peak is located at 436 nm, indicating that the material can emit ultraviolet light.

Example 3

Add 0.2326g (0.8mmol) nickel nitrate hexahydrate, 0.1362g (12.6mmol) boron powder, 0.0240g (0.4mmol) silicon dioxide powder, 0.7656g (11mmol) boron trioxide powder to 25mL absolute ethanol in sequence, Heat and stir in a water bath at 80°C until dry. Put the dried mixed powder in a graphite crucible with a cover, place the graphite crucible in a high-temperature tube furnace, heat it to 1450°C in an argon atmosphere with a flow rate of 150mL/min, and heat it at a constant temperature for 3 hours. After cooling down, off-white fluffy powder is collected on the graphite crucible wall and cover to obtain fluorescent boron carbide nanobelts.

Claims (6)

1. a kind of preparation method of fluorescence boron carbide nanobelt, it is characterised in that: with nickel oxide or nitric acid nickel powder, boron powder, dioxy SiClx powder and diboron trioxide powder are raw material, according to reaction equation 2xNiO+xSiO₂+(4x+2y)B+2yB₂O₃=xNi₂Si+ (2x+3y)B₂O₂, wherein 0.01≤x/y≤0.15, weighs raw material in molar ratio, load weighted raw material is uniformly mixed in anhydrous In ethyl alcohol, heating stirring to drying；Then the mixture after drying is placed in graphite crucible with cover, is put into high temperature process furnances In, be heated to 1350~1600 DEG C under inert protective atmosphere, be heat-treated 1~5 hour, after cooling down with furnace in graphite crucible wall and It covers and collects linen lint sprills, obtain fluorescence boron carbide nanobelt.

2. the preparation method of fluorescence boron carbide nanobelt according to claim 1, it is characterised in that: the nickel oxide or nitre Sour nickel powder, boron powder, diboron trioxide powder, silicon dioxide powder purity be not less than 98%.

3. the preparation method of fluorescence boron carbide nanobelt according to claim 1, it is characterised in that: 0.05≤x/y≤ 0.1。

4. the preparation method of fluorescence boron carbide nanobelt according to claim 1, it is characterised in that: by load weighted raw material It is uniformly mixed in dehydrated alcohol, heating stirring is to drying at 50~90 DEG C.

5. the preparation method of fluorescence boron carbide nanobelt according to claim 1, it is characterised in that: in inert protective atmosphere Under be heated to 1400~1500 DEG C, be heat-treated 1~3 hour.

6. the preparation method of fluorescence boron carbide nanobelt according to claim 1, it is characterised in that: the inertia protects gas Atmosphere is the argon atmosphere that flow velocity is 80~200mL/min.