Sb^(5+)掺杂TiO_2纳米带的制备及其乙醇气敏性能研究

Preparation and ethanol gas-sensing properties of Sb^(5+)-doped TiO_2 nanobelts

采用水热法制备纯的及Sb5+掺杂的TiO2纳米带,并用XRD和TEM对样品进行表征。研究结果表明:700℃焙烧的TiO2纳米带依然保持为锐钛矿相;掺杂后TiO2纳米带的形貌基本保持不变,是长5~10μm,宽100~300 nm的纳米带结构。在最佳工作温度下,TiO2纳米带对乙醇气体具有快速的响应和恢复特性;Sb5+掺杂不仅可以提高TiO2纳米带的灵敏度,而且降低最佳工作温度,由掺杂前的400℃降低为掺杂后的300℃;在n(Sb)/n(Ti)=7.5%的最佳掺杂量下,对体积分数为100×10-6的乙醇气体的响应时间为19 s,恢复时间为11 s,灵敏度为13.82,且检测下限可达到1×10-6。

Undoped and Sb-doped TiO2 nanobelts were prepared by a simple hydrothermal process combined with post-annealing. The samples were characterized by X-ray powder diffraction （XRD） and transmission electron microscopy （TEM）. The results show that all samples calcined at 700 ℃are anatase and the nanobelts are 5-10 μm in length and 100-300 nm in width. All TiO2 nanobelts show good response-recovery characteristics at the optimal working temperature. Compared with the undoped TiO2 nanobelts, Sb-doped TiO2 nanobelts show an enhancement of the sensing sensitivity, as well as a decrease of the optimal working temperature from 400 ℃ to 300 ℃. The optimum Sb doping amount of TiO2 nanobelts for ethanol sensing is 7.5% （i.e. molar ratio of Sb to Ti of 7.5%）. TiO2 nanobelts with molar ratio of Sb to Ti of 7.5% show the highest response with a value of 13.82 and the response and recovery times to 100×10-6 ethanol are 19 and 11 s, respectively. Moreover, the low detection limit of ethanol is estimated to be 1×10-6.