| 以RF/SiO2复合气凝胶为前驱体制备介孔α-SiC |
| Preparation of Mesoporous α-SiC from RF/SiO2 Composite Aerogels |
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| 摘要: 以间苯二酚(R)和甲醛(F)为碳源，3-氨丙基三乙氧基硅烷为硅源，无水乙醇为溶剂，利用简捷的一步溶胶-凝胶法和超临界干燥工艺制备RF/SiO2复合气凝胶。RF/SiO2复合气凝胶经碳热还原、煅烧、酸洗等一系列工艺制备出介孔碳化硅(SiC)，采用XRD、FTIR、NMR、SEM、TEM和氮气吸附-脱附等分析手段对制备的介孔SiC进行了表征。结果表明，介孔SiC材料为纯的α-SiC，平均晶粒大小为15 nm，BET比表面积为106 m2·g-1，孔径主要分布在21.7 nm和61 nm附近，SiC纳米颗粒大小和分布均匀。 |
| 关键词: 介孔碳化硅 溶胶-凝胶 超临界干燥 碳热还原 |
| 基金项目: |
| Abstract: RF/SiO2 gels were synthesized in one pot by simply mixing of the monomers, and then dried to aerogels by supercritical CO2 fluid drying. Mesoporous silicon carbide (SiC) was formed from the RF/SiO2 composite aerogels after heat treatment (carbothermal reaction at 1 500 ℃ for 3 h under Ar and air calcination at 550 ℃ for 3 h) and purifying (acid-washing, filtering, drying). XRD, FTIR, NMR, SEM, TEM and nitrogen adsorption/desorption porosimetry were used to characterize the as-prepared mesoporous SiC. The results indicate that the resulting SiC was pure α-SiC, the average crystallite size was approximately 15 nm. The mesoporous SiC specimen possessed a BET surface area of 106 m2·g-1 which approached to the specific surface area of porous SiC or SiC nanoparticles reported in other papers, a narrow pore size distribution, and a fairly uniform size and array. These mesoporous SiC could possibly be used as thermal insulators, catalysts, adsorbents or electrode materials. |
| Keywords: mesoporous silicon carbide sol-gel supercritical drying carbothermal reduction |
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| 孔 勇,沈晓冬,崔 升,仲 亚.以RF/SiO2复合气凝胶为前驱体制备介孔α-SiC[J].无机化学学报,2012,28(10):2071-2076. |
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