淬火处理对TiO_2纳米管阵列电极性能影响

Effect of Quenching on Properties of TiO_2 Nanotube Arrays

为使TiO2纳米管阵列电极更好地应用于太阳能电池中,通过恒压阳极氧化法以0.5%(w,质量分数)NH4F/甘油作为电解液,在钛基体上制备出了TiO2纳米管阵列.随后将TiO2纳米管阵列电极在水中进行不同温度淬火处理,通过X射线衍射(XRD)仪、场发射扫描电子显微镜(FESEM)、X射线光电子能谱(XPS)和循环伏安法(CV)研究经淬火处理的TiO2纳米管阵列的形貌、晶体结构和电化学性能.研究得出TiO2纳米管阵列经淬火处理其表面获得更多Ti3+缺陷点和TiO2纳米碎片.经0℃淬火处理的TiO2纳米管阵列电极出现了更多Ti3+缺陷点和OH基团,且有更多的纳米碎片出现,其光电化学性能得到了大幅度提高,其40min光照对甲基橙的光催化降解率高达96.2%.

To increase the performance of TiO2 nanotube array electrodes in solar cells, we prepared self-organized TiO2 nanotube arrays on a titanium substrate in 0.5% （w, mass fraction） NH4F/glycerol by anodic oxidization at a constant potential. The electrodes were then quenched in water at different temperatures. These quenched TiO2 nanotube array electrodes were then characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, X-ray photoelectron spectroscopy （XPS） and cyclic voltammetry （CV）. Experimental results indicated that the quenching process produced many surface defects and also resulted in fragmentation of the TiO2 nanotubes. We found that the sample quenched in water at 0 ℃ contained the more Ti3＋ surface defects, OH groups and nanotube fragments. These properties improved its photoelectrochemical performance significantly. This sample resulted in 96.2% photodegradation rate of methyl orange after irradiation for 40 min.