中文摘要：

摘要：采用溶胶凝胶法制备了纯TiO2和掺杂质量分数为5％，7％和9％CuO的TiO2纳米粉体，并对样品进行了不同温度（500，700和900℃）的退火处理。通过涂敷法制备成气敏元件，利用XRD和SEM对样品的结构和表面形貌进行了表征，并利用气敏测试系统检测其气敏特性。研究了CuO掺杂质量分数和退火温度对TiO2厚膜气敏性能的影响，进一步讨论了TiO2厚膜的气敏机理。结果表明：CuO的掺杂有效抑制了TiO2晶粒的生长，增加了对光子的利用率，降低了工作温度，提高了气敏特性。700℃退火后，质量分数为7％的CuO掺杂TiO2样品的结晶尺寸达到14．5nm，气敏元件表现出对丙酮蒸汽单一的选择性，灵敏度为3567，响应和恢复时间均为2S。

英文摘要：

Abstract： The pure TiO2 and the CuO-doped TiO2 nanopowders with the mass fractions of 5%, 7% and 9% were prepared by the sol-gel method, and the samples were annealed at different tem- peratures （500, 700 and 900 ℃）. The gas sensors were obtained with the coating method. The structures and surface morphologies of the samples were characterized by X-ray diffration （XRD） and scanning electron microscope （SEM）, and the gas sensing properties were detected by the gas sensor test system. The effects of the CuO-doped mass fraction and annealing temperature on the gas sensing properties of TiO2 thick films were studied. Meanwhile, the gas-sensing mecha- nism of TiO2 thick films was discussed. The results indicate that the doping of CuO can effective- ly restrain the growth of TiO2 grains, increase the utilization of the photon, reduce the operating temperature and improve the gas sensing properties. The crystalline size of the CuO-doped TiO2 sample with the mass fraction of 7% reaches 14.5 nm after the anneal at 700 ℃. The gas sensor behaves the single selectivity to the acetone steam, the sensitivity can be up to 3 567, and both the response and recovery time are 2 s.