环氧化物法制备锑掺杂氧化锡气凝胶

Antimony-Doped Tin Oxide Aerogel Based on Epoxide Additional Method

以无机金属盐为前驱体,采用环氧丙烷添加法结合CO2超临界流体干燥和热处理工艺,制备了不同锑掺杂浓度的二氧化锡(ATO)气凝胶.所得气凝胶为深蓝色块体,平均密度约为600 mg?cm-3,锑掺杂浓度在5%到20%(x)之间.电子显微镜图片显示ATO气凝胶的骨架由粒径约为数十纳米的颗粒堆积而成,而这些颗粒又由数纳米的初级球形颗粒构成.X射线衍射谱表明,样品的主要晶相为SnO2四方相金红石结构,锑的掺杂仅引起微小的晶格畸变.X射线光电子谱显示锡元素以+4价态存在,而锑则具有+3和+5的混合价态.四探针电阻率测试仪的结果表明,ATO气凝胶的电阻率在2.7-40Ω?cm之间变化,其中在锑掺杂浓度(x)为12%时具有最低电阻率.

Antimony-doped tin oxide （ATO） aerogels were prepared from inorganic salts via epoxide additional method, CO2 supercritical fluid drying and thermal treatment. ATO samples were dark blue monoliths with average density of about 600 mg？cm-3 and Sb concentrations of 5%-20%（x）. Electron microscopy showed that the skeleton of the ATO aerogels consisted of particles of size of dozens of nanometers, which further consisted of primary particles of size about several nanometers. X-ray diffraction spectra showed that the main crystal structure within the ATO aerogels was tetragonal tin dioxide, while Sb doping only resulted in minor lattice distortion. X-ray photoelectron spectroscopy indicated that the valence state of tin was＋4, while antimony was mixed with＋3 and＋5 valences. Four-point probe resistivity analysis exhibited that the electrical resistivity of the ATO aerogels changed from 2.7 to 40Ω？cm, among which the aerogel with 12%Sb had the lowest resistivity.