溶胶凝胶模板法合成ITO纳米管及其氢敏性能

采用简单的溶胶凝胶阳极氧化铝模板法制备了ITO纳米管.通过FE-SEM、HRTEM、XRD对其微观形貌、结构、相组成等进行了表征和分析,并测试了其对H_2的气敏特性.结果表明,所得纳米管是由10～20 nm晶粒组成的多晶结构,壁厚约为25 nm,平均直径约250 nm,与AAO (Anodic Aluminum Oxide)模板的直径相同.产物在550 ℃热处理后为立方铁锰矿结构的In_2O_3,Sn~(4+)已经掺杂到In_2O_3的晶格中.所得ITO纳米管常温下对氢气具有较好的敏感性及稳定性.

Preparation and Hydrogen Sensing Properties of ITO Nanotubes by Sol-Gel Method Combined with Porous Anodic Aluminum Oxide Template

Tin-doped indium oxide (ITO) nanotubes were fabricated by means of a simple sol-gel method combined with porous anodic aluminum oxide template. Scanning electron microscopy (SEM), Transmission electron microscopy, HRTEM, and X-ray diffraction were applied to characterize the morphology and structure of the as-prepared nanotubes. The gas sensing properties of the ITO nanotubes to wards H_2 (1000 μg/g) have been investigated. It has been demonstrated that the as-prepared nanotubes exhibited a polycrystalline microstructure, which are composed of nanoparticles with sizes ranging from 10 to 20 nm. The mean outer diameter of these nanotubes is about 250 nm, corresponding to the diameter of channels in the AAO template and the average thickness of the tube wall is about 25 nm. After postannealing at 550 ℃, X-ray diffraction pattern indicates that they are of a cubic bixbyite crystal structure and Sn~(4+) ions were homogeneously doped into the In_2O_3 crystal lattice. The as-synthesized ITO nanotubes showed excellent gas-sensing properties to H_2 in terms of sensor response and selectivity at room temperature.