阅读说明：本技术 一种掺杂的二氧化钒微米管阵列的制备方法 (Preparation method of doped vanadium dioxide micron tube array ) 是由 赵春旺 李子剑 于 2019-06-24 设计创作，主要内容包括：一种掺杂的二氧化钒微米管阵列的制备方法,将金属钒原材料与掺杂元素按预定比例配比,将配比好的原材料用熔炼等方法制成均匀的掺杂的钒块体,然后切成薄片,采用电流加热的热氧化法,在掺杂的钒片表面生成近矩形截面的、中空的、直立于掺杂的钒片表面的掺杂的二氧化钒微米管阵列。本发明的优点是：掺杂方法简单易行、成本低廉、对设备要求低、周期短,利于工业化实现。通过该掺杂方法能有效的调节二氧化钒微米管阵列的相变温度,有利于将二氧化钒晶体优异的相变性能应用于红外探测器、热致变色、热能管理等领域。(a preparation method of a doped vanadium dioxide micron tube array comprises the steps of proportioning a metal vanadium raw material and a doping element according to a preset proportion, preparing the proportioned raw material into uniform doped vanadium blocks by methods of smelting and the like, then cutting the uniform doped vanadium blocks into slices, and generating the doped vanadium dioxide micron tube array which is approximately rectangular in cross section, hollow and upright on the surface of a doped vanadium plate by adopting a current heating thermal oxidation method. The invention has the advantages that: the doping method is simple and easy to implement, low in cost, low in equipment requirement, short in period and beneficial to industrial implementation. The doping method can effectively adjust the phase change temperature of the vanadium dioxide micron tube array, and is beneficial to applying the excellent phase change performance of the vanadium dioxide crystal to the fields of infrared detectors, thermochromism, heat energy management and the like.)

1. A preparation method of a doped vanadium dioxide micron tube array is characterized by comprising the following steps:

the method comprises the following steps: weighing small particle raw materials of metal vanadium and doping elements according to a certain mass ratio;

step two: uniformly mixing the doping elements and vanadium into a block by adopting methods such as smelting and the like;

step three: cutting the prepared block into doped vanadium sheets with the length of 20 mm, the width of 3 mm and the thickness of 0.2 mm;

Step four: heating the doped vanadium sheet to 1100-1900 ℃ in air at room temperature by adopting a current heating method, and keeping for 10-20 seconds;

Step five: and stopping heating, and naturally cooling the doped vanadium sheet to room temperature, namely obtaining the doped vanadium dioxide micron tube array which has a nearly rectangular cross section, is hollow and is vertical to the surface of the doped vanadium sheet on the surface of the doped vanadium sheet.

2. The method for preparing the doped vanadium dioxide microtube array according to claim 1, wherein: the metal vanadium and the raw material of the doping element are proportioned according to a certain mass ratio.

3. The method for preparing the doped vanadium dioxide microtube array according to claim 1, wherein: the doping elements and vanadium are uniformly mixed into a block by methods such as smelting.

4. the method for preparing the doped vanadium dioxide microtube array according to claim 1, wherein: the doped vanadium mass is cut into thin doped vanadium sheets.

5. the method for preparing the doped vanadium dioxide microtube array according to claim 1, wherein: and heating the doped vanadium sheet to 1100-1900 ℃, and keeping for 10-20 seconds.

6. The method for preparing the doped vanadium dioxide microtube array according to claim 1, wherein: the doped vanadium dioxide micron tube obtained on the surface of the doped vanadium sheet is nearly rectangular in section and hollow, the side length of the rectangular section is 1-22 microns, and the length of the doped vanadium dioxide micron tube can reach more than 600 microns.

Technical Field

the invention relates to a preparation method of a doped vanadium dioxide micron tube array, in particular to a method for preparing a doped vanadium dioxide micron tube array, which comprises the steps of proportioning metal vanadium and a raw material of a doped element according to a preset proportion, uniformly mixing the doped element and the vanadium into a block by using methods such as smelting and the like, cutting the block into slices, oxidizing the surface of a doped vanadium sheet by using methods such as a current heating thermal oxidation method and the like, liquefying vanadium oxide at high temperature, and cooling and crystallizing to generate the doped vanadium dioxide micron tube array which is approximately rectangular in section, hollow and upright on the surface of the doped vanadium sheet.

Background

Vanadium dioxide is a functional material with thermotropic phase transition characteristics, and the phase transition temperature of the vanadium dioxide is 68 ℃, and reversible phase transition of a high-temperature metal phase and a low-temperature insulator phase occurs at the temperature. Vanadium dioxide has a phase transition temperature that is closest to room temperature than other vanadium oxides and has therefore been the subject of major research in recent years. However, the temperature is still a certain difference from room temperature, so how to further reduce the phase transition temperature and maintain good phase transition performance is the current research focus. Doping vanadium dioxide is an effective means for lowering the phase transition temperature, but has two defects from the current research situation: firstly, the existing process for preparing doped vanadium dioxide is complex, long in time, high in cost and not easy to implement industrial production; secondly, although the phase transition temperature of the doped vanadium dioxide is reduced to 28 ℃ in a literature report, the phase transition endothermic peak and exothermic peak of the vanadium dioxide are obviously weakened, so that the phase transition performance is deteriorated, and the application is not facilitated.

disclosure of Invention

The invention aims to provide a method for preparing a doped vanadium dioxide microtube array, which has the advantages of simple process, short period, low cost and easiness in control, and can effectively adjust the phase change temperature to 25.68 ℃ of room temperature on the premise of keeping good phase change performance.

in order to achieve the purpose, the preparation method comprises the following steps:

The method comprises the following steps: converting into mass ratio according to preset atomic ratio and weighing small particle raw materials of doping elements and metal vanadium;

step two: smelting the proportioned raw materials into blocks in smelting equipment such as a vacuum arc furnace and the like;

step three: cutting the smelted block into thin doped vanadium sheets;

Step four: in the air at room temperature, the doped vanadium sheet is electrified with direct current or alternating current to be rapidly heated, and when the temperature reaches 1100-1900 ℃, the temperature is kept for 10-20 seconds;

Step five: and cutting off a power supply, and naturally cooling the doped vanadium sheet to room temperature to obtain the hollow vanadium dioxide micron tube array with the approximately rectangular cross section and doped with other elements on the surface of the doped vanadium sheet.

the invention adopts methods such as vacuum arc melting and the like and a current thermal oxidation method to dope other elements and synthesize micron-scale vertical tubular doped vanadium dioxide single crystals with nearly rectangular sections in an air environment at room temperature. The doping method has the advantages of simple process, short period, low cost and easy control, and can effectively adjust the phase change temperature to 25.68 ℃ of room temperature on the premise of keeping good phase change performance.

when the product is applied to lithium/sodium ion battery electrode materials, infrared detectors, laser protection, intelligent temperature control materials, thermochromism and heat energy regulation switches, the product is expected to show excellent metal insulator conversion performance, electrochemical performance and electrocatalysis performance. The concrete benefits are as follows:

(1): the doping method has the advantages of simple process, short period, low cost and easy control, and can effectively adjust the phase-change temperature to 25.68 ℃ of room temperature on the premise of keeping good phase-change performance.

(2): the main metal vanadium adopted by the invention does not need too high purity, the cost is low, the yield is high, the used equipment is simple, the reaction is easy to control, and the method is beneficial to industrial production.

(3): the vanadium dioxide doped micron tube prepared by the invention has unique discrete vertical and hollow structures, and can provide a buffer space for the expansion and contraction of the micron tube, so that the cracking caused by the volume change of the micron tube can be greatly relieved, and the cycling stability of the micron tube in service is finally obviously improved; and the electrolyte/electrolyte is ensured to be fully contacted with the vanadium dioxide in the application of lithium batteries and catalysts, so that the electrochemical reaction resistance is reduced, and the performance of the lithium/sodium ion battery is further improved.

Drawings

FIG. 1 is a side scanning electron microscope photograph of a synthesized product of example 1 of the present invention.

FIG. 2 is a front scanning electron microscope photograph of a synthesized product of example 1 of the present invention.

FIG. 3 is an X-ray diffraction pattern of the product synthesized in example 1 of the present invention.

FIG. 4 is a differential scanning calorimetry plot of the product synthesized in example 1 of the present invention.

FIG. 5 is a side scanning electron microscope photograph of a synthesized product of example 2 of the present invention.

FIG. 6 is a front scanning electron microscope photograph of a synthesized product of example 2 of the present invention.

FIG. 7 is an X-ray diffraction pattern of a product synthesized in example 2 of the present invention.

FIG. 8 is a differential scanning calorimetry plot of the product synthesized in example 2 of the present invention.

Detailed Description

The invention will now be further described by way of examples, which are provided for illustration purposes only and are not intended to be limiting.