以沉淀白炭黑为硅源制备硼掺杂碳化硅的研究

Preparation of the B-doped SiC using precipitated silica-white as silicon source

为低成本、规模化制备高比表面积碳化硅,以工业级沉淀白炭黑为硅源,葡萄糖粉剂为碳源,采用简单的碳热还原法制备了硼掺杂高比表面积碳化硅。利用X射线衍射仪、扫描电镜、比表面积测试仪和紫外-可见吸收光谱测试方法对碳化硅的晶型、形貌、表面性质及能带结构进行了表征。分析结果表明:B原子进入SiC晶格并取代Si点位,在1 350℃焙烧温度时,SiC具有最高比表面积和较低禁带宽度,随着B/Si摩尔比增大,SiC结晶度提高,比表面积减小,禁带宽度减小。

Boron-doped SiC with high specific surface area was prepared by a simple carbothermal reduction method using industrial-grade precipitated silica-white and glucose powder as carbon and silicon sources respectively.It provides an effective method for low cost and large-scale preparation of SiC with high specific surface area.The crystal structure,morphology,surface property and band gap structure of SiC were characterized using X-ray diffraction,scanning electron microscopy,specific surface area analyzer,and ultraviolet-visible absorption spectroscopy.The characterization result indicates that B atoms have doped into the SiC lattice and substituted Si sites.When the roasting temperature is 1350℃,the SiC has the largest specific surface area and a lower band gap.With the B/Si molar ratio increasing,the crystallinity of SiC increased,while the band gap and specific surface area of SiC decreased.