水热法制备掺杂钇的二氧化钛及其对甲醛气敏性能研究

Study on Synthesis of TiO₂ Doped with Yttrium by Hydrothermal Method and the Gas Sensing Properties towards Formaldehyde

摘要: 本文首先通过溶胶–凝胶法和水热法制备了TiO₂粉末和掺杂稀土离子Y的TiO₂粉末，并通过X-射线衍射谱(XRD)对制备的样品结构进行了表征，结果表明，制备的TiO₂粉末为锐钛矿结构；稀土离子的掺杂抑制了TiO₂晶粒生长。其次通过气敏测试仪测试所制备的样品对甲醛的气敏性，结果发现水热法制备的掺杂Y的TiO₂(TiO₂:Y-HT)对甲醛有较高的灵敏性。并进一步研究了该样品对甲醛浓度的敏感性、响应–恢复时间以及在不同温度下的敏感性，结果显示，最佳操作温度为250℃，随着浓度的增加呈现增加的趋势，响应时间约为30 s，恢复时间约为35 s。

Abstract: In this paper, the TiO₂ powder and TiO₂ powders doped with yttrium ion have been prepared by the sol-gel method and hydrothermal methods, and the structures of the samples have been characterized by the XRD. The results of XRD indicate that the structure of prepared TiO₂ powder is anatase and rare earth ion doping agents can restrain the growth of TiO₂ crystals. Moreover, the formaldehyde gas sensing properties of the prepared samples have been measured by the gas sensing instrument. The results show that the TiO₂ doped with Y and prepared by hydrothermal method (TiO₂:Y-HT) exhibits better sensitivity towards formaldehyde. The concentration-sensitivity, response-recovery time and temperature-sensitivity of TiO₂:Y-HT have been furthermore studied. The results indicate that the best operation temperature is 250˚C, the sensitivity increases with the increasing of formaldehyde concentration, the response time is about 30 s, and the recovery time is about 35 s.