Method for synthesizing high specific surface mesoporous silicon carbide at low temperature and silicon carbide product

Abstract

The present invention discloses a method for low-temperature synthesis of a high specific surface mesoporous silicon carbide, and a silicon carbide product thereof. The method comprises: preparing a C / SiO2 precursor by using a triblock copolymer P123 as a templating agent, using tetraethyl orthosilicate as a silicon source and using furfuryl alcohol as a carbon source; and in the presence of an inert gas, carrying out magnesium heat reducing and washing drying on the C / SiO2 precursor to obtain the silicon carbide material, wherein the crystal form is 3C-SiC. According to the present invention, with the method, the preparation temperature is substantially reduced, the reaction temperature can be reduced to less than 700 DEG C, the energy consumption is significantly reduced, and the precursor preparation time is short and only requires about 4 days; the precursor material selects the mutually-supported and interactively-growing C / SiO2 as the precursor, such that the skeleton structure during the reaction process can be retained to the maximal degree, and the specific surface area of the prepared material is large and can achieve 600-800 m<2> / g; and the prepared silicon carbide mesoporous material has characteristics of uniform particle size and uniform particle distribution, and has the size of 10-20 nm.

Description

technical field [0001] The invention belongs to the technical field of material synthesis, and in particular relates to a method for synthesizing high specific surface mesoporous silicon carbide at low temperature and a silicon carbide product. Background technique [0002] Silicon carbide (SiC), commonly known as emery, has a hardness close to that of diamond, a high band gap, high thermal conductivity, a small dielectric constant and a high electron saturation mobility. Based on its many excellent physical and chemical properties, SiC shows great application prospects in the fields of non-ferrous metal smelting industry, building materials ceramics, energy-saving industry and electronic materials. At present, the main method for preparing SiC in industry is the Acheson method, that is, mixing coke powder and quartz sand and reacting at a high temperature above 2000°C to prepare SiC. Scholars at home and abroad have conducted a lot of research on the preparation of SiC mat...

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Problems solved by technology

[0005] The common feature of the above synthesis methods is that high temperature reaction is required, and the reaction temperature is generally between 1250 and 1800 °C, which undoubtedly increases the preparation cost and is very unfavorable for the practical application of the material

In addition, the high temperature process will destroy the microscopic morphology and structure of SiC materials, leading to SiC agglomeration, and the prepared silicon carbide materials usually have small specific surface area, low product purity and uneven particle size distribution, which further limit its industrial application.

Therefore, the development of a relatively mild SiC synthesis process has become an urgent problem to be solved. The specific surface area of ​​SiC materials prepared in the prior art is generally lower than 200m 2 / g, a large amount of hydrofluoric acid and other strong corrosive solutions need to be used in the preparation process, and the pollution is serious

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