多孔硅的模板限制镁热还原法制备及性能

采用一种基于气-固反应机制的模板限制镁热还原法,以SiO2气凝胶为模板在低温(650℃)下制备出一种高比表面积纳米多孔硅材料.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外(FTIR)光谱、X射线光电子能谱(XPS)和比表面积(BET)分析等表征手段对样品的成分、物相结构、微观形貌和孔结构进行分析,并初步研究了材料的光学特性和电化学性能.结果表明,产物为纳米硅晶体颗粒组成的多孔结构,保留了与原始气凝胶模板相似的微观形貌,比表面积高达602 m2·g-1.该材料在室温下表现出显著的红光光致发光特性,且具有较高的储锂容量和较好的嵌入/脱出锂性能.

Confined Synthesis and Properties of Porous Silicon from Silica Aerogel Templates by Magnesiothermic Reduction

Novel nanoporous silicon was successfully converted from SiO₂ aerogels by a template-confined magnesiothermic reduction at low temperature (650°C) based on a gas-solid reaction. The composition, crystal structure, morphology, and pore structure of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett- Teller (BET) surface area analysis. Their optical and electrochemical properties were also investigated. The results indicated that the products consisted of nanocrystalline silicon, retained a morphology similar to that of the original templates, and possessed a specific surface area as high as 602 m²·g^-1. They also showed red photoluminescence at room temperature and had a high capacity and good Li-ion insertion/extraction properties for use in lithium ion batteries.