总气压与Ar/O2流量比对直流对向靶磁控溅射TiO2薄膜光催化性能的影响

摘要

Polycrystalline TiO2 thin films were prepared by direct current facing-target magnetron sputtering at different sputtering pressures and Ar/O2 flow ratios.The average thickness of all prepared films was 200 nm,measured by surface roughness tester.With increase in sputtering pressure (ptot),the prepared films changed from mixtures of anatase and rutile phases to pure anatase.The influences of different sputtering pressures and Ar/O2 flow ratios on surface morphology of prepared films were investigated by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM).The film surface was found to become rougher with increasing pressure and Ar/O2 flow ratios.Photocatalytic activities of the prepared TiO2 thin films were investigated by decomposition of iso-propanol (IPA) with initial concentration of 100x 10-6 (volume fraction) under UV irradiation.The IPA was oxidized to acetone and further to carbon dioxide.TiO2 thin film deposited at 2.0 Pa with an AdO2 flow ratio of 1:1 showed the highest photocatalytic activity and maintained a high stability constant during the reaction.%采用对向靶磁控溅射法在不同气压和Ar/O2流量比条件下,以氟化SnO2(FTO)导电玻璃为基底制备了多晶TiO2薄膜.台阶仪测量结果显示所制备TiO2薄膜的平均厚度约为200 nm.随着溅射气压的升高,TiO2薄膜由锐钛矿与金红石混晶结构转变为纯锐钛矿结构.分别采用场发射扫描电镜(FESEM)和原子力显微镜(AFM)分析了不同气压和Ar/O2流量比对TiO2薄膜表面形貌的影响,结果显示TiO2薄膜的表面粗糙度随溅射总气压和Ar/O2流量比的增加而增大.以初始浓度为100x10-6(体积分数)的异丙醇(IPA)气体为目标物检测所制备TiO2薄膜的光催化性能,并分析该气相光催化反应的机理,在紫外照射条件下异丙醇先氧化为丙酮再被氧化为CO2.当总溅射气压为2.0 Pa、Ar/O2流量比为1∶1时,溅射所得TiO2薄膜具备最优光催化活性并可在IPA降解反应中保持较高的催化活性和稳定性.