阅读说明：本技术 一种氧化铋纳米线及其制备方法 (Bismuth oxide nanowire and preparation method thereof ) 是由 李建辉 谢天 杨春军 盖军旗 杜军军 王丽婷 毛磊 崔博帅 于 2020-05-28 设计创作，主要内容包括：本发明涉及纳米材料技术领域,具体公开一种氧化铋纳米线及其制备方法。所述氧化铋纳米线的制备方法,包括如下步骤：对铋锡合金进行热蒸发处理使所述铋锡合金中的铋元素蒸发,产生的铋蒸气在表面涂覆有金胶纳米粒子的基底上与氧气反应形成氧化铋纳米线。本发明提供的制备方法以铋锡合金作为蒸发源制备氧化铋纳米线,工艺简单,产量高,所获得的氧化铋纳米线形貌规整,长径比大,粗细均匀,几乎没有纳米颗粒产生,且纯度高,不存在掺杂的锡元素。(The invention relates to the technical field of nano materials, and particularly discloses a bismuth oxide nanowire and a preparation method thereof. The preparation method of the bismuth oxide nanowire comprises the following steps: carrying out thermal evaporation treatment on the bismuth-tin alloy to evaporate bismuth elements in the bismuth-tin alloy, and reacting the generated bismuth vapor with oxygen on a substrate with the surface coated with gold colloid nano particles to form bismuth oxide nano wires. The preparation method provided by the invention has the advantages that the bismuth tin alloy is used as the evaporation source to prepare the bismuth oxide nanowire, the process is simple, the yield is high, the obtained bismuth oxide nanowire is regular in shape, large in length-diameter ratio, uniform in thickness, almost free of nanoparticles, high in purity and free of doped tin elements.)

1. A preparation method of bismuth oxide nanowires is characterized by comprising the following steps: the method comprises the following steps: carrying out thermal evaporation treatment on the bismuth-tin alloy to evaporate bismuth elements in the bismuth-tin alloy, and reacting the generated bismuth vapor with oxygen on a substrate with the surface coated with gold colloid nano particles to form bismuth oxide nano wires.

2. The method of preparing bismuth oxide nanowires of claim 1, wherein: the mass ratio of bismuth to tin in the bismuth-tin alloy is 1: 0.5 to 1.5.

3. The method of preparing bismuth oxide nanowires of claim 1, wherein: the bismuth-tin alloy is prepared by smelting massive metal bismuth and tin serving as raw materials in a vacuum tube furnace.

4. The method of preparing bismuth oxide nanowires of claim 1, wherein: the temperature of the thermal evaporation treatment is 500-700 ℃.

5. The method of preparing bismuth oxide nanowires of claim 1, wherein: the time of the thermal evaporation treatment is 3-5 h.

6. The method of preparing bismuth oxide nanowires of claim 4, wherein: the bismuth vapor passes through inert gas flow containing oxygen, the substrate of a low-temperature region at the downstream position of the bismuth-tin alloy, the surface of which is coated with gold colloid nano particles, reacts with the oxygen to form bismuth oxide nano wires, and the volume content of the oxygen in the inert gas containing the oxygen is 1-3%.

7. The method of preparing bismuth oxide nanowires of claim 6, wherein: the temperature of the low-temperature zone where the substrate is located is 300-350 ℃.

8. The method for preparing bismuth oxide nanowires according to any one of claims 1 to 7, characterized in that: the substrate is a monocrystalline silicon substrate or a quartz substrate coated with gold colloid nano particles on the surface.

9. A bismuth oxide nanowire, characterized by: the bismuth oxide nanowires according to any one of claims 1 to 8.

10. The bismuth oxide nanowires of claim 9, wherein: the diameter of the nanowire is 30-100 nm; the length is 1 to 30 μm.

Technical Field

The invention relates to the technical field of nano materials, in particular to a bismuth oxide nanowire and a preparation method thereof.

Background

Bismuth oxide (Bi)₂O₃) As an advanced functional material, the material is widely applied to the fields of electronic ceramic materials, electrolyte materials, photoelectric materials, high-temperature superconducting materials, ferroelectric materials, catalysts, combustion improvers, sensor materials and the like due to excellent physicochemical properties such as high refractive index, high dielectric constant and excellent photoconductive properties. With the development and research of industrial technology, the application field of bismuth oxide is still expanding. Therefore, the preparation method of nano bismuth oxide with simple production process, high product purity and good uniformity is sought and increasingly receives attention.

At present, the preparation method of nano bismuth oxide can be divided into a liquid phase method and a gas phase method. Among them, the research work related to the liquid phase method is widely carried out, the method usually needs post-treatment, nano bismuth oxide is easy to shrink and agglomerate during drying, and chemical reagents discharged by the method are easy to cause environmental pollution. The method for preparing the nano bismuth oxide by the gas phase method mainly comprises the following steps: chemical precipitation, plasma, melt spray oxidation, and chemical vapor condensation. The plasma method has the advantage of short flow, but needs special equipment, and has large one-time investment and high cost; the melting spray oxidation method has short flow, but has the problems of short service life of a nozzle, incomplete bismuth oxidation, large formed nano bismuth oxide particles, uneven particle size distribution and the like; the chemical vapor condensation method has higher requirements on equipment materials and limited industrial development; the chemical precipitation method has become a mainstream method for preparing bismuth oxide in the gas phase method because the chemical precipitation method has the advantages of simple process, easy control, easy operation, easy realization of large-scale industrial production and small environmental pollution, however, the uniformity of product particles is poor and the particle size is difficult to ensure because the precipitation product in the precipitation process is complex and the nucleation and condensation process is difficult to control.

In addition, the metal vapor oxidation method for preparing nano zinc oxide is mature, and zinc oxide with different forms is successfully prepared, but when the method is used for preparing nano bismuth oxide, expensive heating equipment (such as a plasma generation system, high-frequency induction heating equipment and the like) is usually needed to be used at a higher temperature, so that the requirements on conditions are severe, and the obtained nano bismuth oxide powder is mostly spherical, so that other bismuth oxide powder with controllable morphology is still difficult to obtain.

Disclosure of Invention

The invention provides a bismuth oxide nanowire and a preparation method thereof, aiming at the technical problems that in the existing preparation process of nano bismuth oxide, the nano bismuth oxide powder is mostly spherical and other bismuth oxide powder with controllable morphology is difficult to obtain.

In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:

a preparation method of bismuth oxide nanowires comprises the following steps: carrying out thermal evaporation treatment on the bismuth-tin alloy to evaporate bismuth elements in the bismuth-tin alloy, and reacting the generated bismuth vapor with oxygen on a substrate with the surface coated with gold colloid nano particles to form bismuth oxide nano wires.

Compared with the prior art, the preparation method of the bismuth oxide nanowire provided by the invention has the advantages that bismuth tin alloy is used as a raw material, the generated bismuth vapor is subjected to reaction and deposition with oxygen on the substrate of a low-temperature region far away from an evaporation source through a thermal evaporation method, nucleation is carried out, and the bismuth oxide nanowire is grown, so that the defect that when pure bismuth is used as the raw material to prepare the nanowire, high-temperature heating is adopted, the vapor pressure of bismuth can be ensured, but the evaporation amount of bismuth is large and difficult to control, the content of the nanowire is low, and partial nanoparticles are generated is overcome; by adopting low-temperature heating, the evaporation amount of bismuth can be reduced, but the obtained bismuth oxide sample still has the problems of short length, small density and undesirable appearance. According to the invention, bismuth-tin alloy is used for replacing pure bismuth as a raw material to prepare the nano-wire, bismuth is alloyed, and the addition of tin element reduces the evaporation amount of bismuth in the thermal evaporation process, so that the bismuth oxide nano-wire with an ideal appearance is obtained, and the tin element is not doped into bismuth oxide, so that the purity of the bismuth oxide nano-wire is ensured. The method has low requirement on equipment, simple process, convenient operation and high yield, and can be widely popularized and applied in laboratories and industrial production in the future.

Further, the mass ratio of bismuth to tin in the bismuth-tin alloy is 1: 0.5-1.5, alloying of bismuth is realized by adding tin element, and evaporation capacity of bismuth in the thermal evaporation process is reduced.

Further, the bismuth-tin alloy is prepared by smelting massive metal bismuth and tin serving as raw materials in a vacuum tube furnace, and repeatedly smelting for 3-5 times in the vacuum tube furnace to obtain the bismuth-tin alloy with uniform components.

Further, the temperature of the thermal evaporation treatment is 500-700 ℃.

Furthermore, the time of the thermal evaporation treatment is 3-5 h, and on the basis of taking the bismuth tin alloy as a raw material, the ideal bismuth oxide nanowire is obtained by adjusting the parameters of the evaporation temperature and the evaporation time.

Further, the bismuth vapor passes through inert gas flow containing oxygen, and the substrate coated with the gold colloid nano particles on the surface of the low-temperature area at the downstream position of the bismuth-tin alloy reacts with the oxygen to form bismuth oxide nano wires, namely the bismuth vapor reacts with the oxygen to form the bismuth oxide nano wires on the substrate of the deposition end of the low-temperature area far away from the evaporation end taking the bismuth-tin alloy as the evaporation source.

Furthermore, the volume content of oxygen in the inert gas containing oxygen is 1-3%, so that a large amount of melt in a bismuth-tin alloy evaporation source of the evaporation source is prevented from being oxidized, the temperature of the selected thermal evaporation treatment is 500-700 ℃, if the evaporation source is oxidized, the evaporation temperature of an oxide film formed on the surface is higher than the temperature of the thermal evaporation treatment, further generation of bismuth vapor is influenced, generation of nanowires is further influenced, and meanwhile, oxygen in the inert gas containing oxygen provides oxygen required by reaction for the formation of the bismuth oxide nanowires.

Furthermore, the temperature of the low-temperature region where the substrate is located is 300-350 ℃, namely the temperature of the deposition end far away from the evaporation end in the quartz tube, so that the deposition of bismuth vapor and the smooth growth of the nanowires are ensured.

Further, the substrate is a monocrystalline silicon substrate or a quartz substrate coated with gold colloid nano particles on the surface. Wherein, the crystal direction [111] of the single crystal silicon substrate is helpful for guiding and limiting the growth direction of the nano wire, and the more regular nano wire is obtained.

Furthermore, the particle size of the gold colloid nano particles is 15-25 nm, the gold colloid nano particles are used as catalysts, and each gold colloid nano particle can catalyze and grow a bismuth oxide nano wire

The invention also provides a bismuth oxide nanowire prepared by the preparation method of the bismuth oxide nanowire.

Furthermore, the diameter of the nanowire is 30-100 nm, the length of the nanowire is 1-30 microns, and the length-diameter ratio of the nanowire is 30-1000.

Compared with the prior art, the bismuth oxide nanowire provided by the invention has the advantages of regular appearance, large length-diameter ratio, uniform thickness, almost no generation of nano particles, high purity and no doped tin element.

Drawings

FIG. 1 is a schematic diagram of an apparatus for preparing bismuth oxide nanowires according to an embodiment of the present invention;

FIG. 2 is an SEM image of bismuth oxide nanowires in example 1 of the present invention;

FIG. 3 is an SEM image of the bismuth oxide nanowires in comparative example 1 of the present invention;

FIG. 4 is an SEM image of bismuth oxide nanowires in comparative example 2 of the present invention;

FIG. 5 is an SEM image of bismuth oxide nanowires in comparative example 3 of the present invention;

fig. 6 is an XRD spectrum of the bismuth oxide nanowire in example 1 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a preparation method of a bismuth oxide nanowire, which comprises the following steps: carrying out thermal evaporation treatment on the bismuth-tin alloy to evaporate bismuth elements in the bismuth-tin alloy, and reacting the generated bismuth vapor with oxygen on a substrate with the surface coated with gold colloid nano particles to form bismuth oxide nano wires.

The bismuth-tin alloy is used as an evaporation source at an evaporation end, firstly, vacuum pumping is carried out, then, inert gas (argon) is introduced to enable the atmosphere in a reaction environment (a quartz tube) to be inert gas containing oxygen, bismuth is evaporated by heating in a low-vacuum state, generated bismuth vapor is conveyed to a deposition end of a low-temperature area far away from the evaporation end using the bismuth-tin alloy as the evaporation source through inert gas flow containing oxygen, then, the bismuth vapor and the oxygen react on a substrate for nucleation and growth, and finally, the required bismuth oxide nanowire is obtained after reaction for a certain time.

In order to better illustrate the preparation method of the bismuth oxide nanowire provided by the embodiment of the present invention, the following further illustrates the preparation method by the embodiment.