退火温度对磁控溅射TiO_2薄膜结构及性能的影响

Effects of Annealing Temperature on Structure and Properties of TiO_2 Films Prepared by Magnetron Sputtering

采用对向靶磁控溅射法在FTO导电玻璃基底上制备了TiO2薄膜,分别在450,℃、500,℃和550,℃条件下对TiO2薄膜进行退火处理;利用X射线衍射(XRD)和扫描电镜(SEM)测试手段分析了不同退火温度对TiO2薄膜晶体结构与表面形貌的影响.以异丙醇(iso-propanol,IPA)为目标物,研究了所制备TiO2薄膜的光催化性能,并分析了该气相光催化反应机理.同时在氙灯照射下,测试了TiO2薄膜的光电流以分析其光电性能.结果表明:当退火温度由450,℃升至550,℃时,TiO2薄膜由纯锐钛矿结构转变为金红石与锐钛矿型混晶结构,其表面形貌则变化不大;TiO2薄膜光催化性能与光电性能均随退火温度的升高而提高,经550,℃退火的TiO2薄膜可将IPA高效降解为丙酮和CO2,其光电流可达0.7,mA并保持稳定.

TiO2 thin films were deposited using DC facing-target magnetron sputtering on FTO substrates and an- nealed under the temperature of 450 ℃, 500 ℃ and 550 ℃, respectively. Influences of different annealing temperatures on the crystalline structure and surface morphology of prepared TiO2 thin films were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. Photocatalytic activities of TiO2 thin films were measured by the decomposition of IPA under Xe lamp irradiation. Mechanism of gas-phase photocatalytic reaction was analyzed. Photovoltaic activities of TiO2 thin films were investigated by photocurrent instrument. Results showed that crystalline structure of TiO2 thin films was transformed from anatase to mix-phase of anatase and rutile while the surface mor- phology changed little under the increasing annealing temperature. IPA could be oxidized to CO2 accompanied by ace- tone as the intermediate product. As the annealing temperature increased, both of photocatalytic activity and photoelec- tric activity of TiO2 thin films became higher. The photocurrent of TiO2 thin film annealed at 550 ℃ was constantly kept at 0.7 mA under the irradiation of Xe lamp.