纳米TiO2∶Zn薄膜电极紫外光电特性研究

采用sol-gel法制备了Zn2+掺杂的锐钛矿相纳米TiO2薄膜电极.通过光电流作用谱和电流-电位（I-U）曲线研〖WTBZ〗究了掺杂不同浓度Zn2+的TiO2薄膜电极的光电特性.由光电流作用谱可知，Zn2+的掺杂可显著影响薄膜电极的光电流大小，且掺杂的最佳浓度与薄膜晶粒尺度有关.在320nm单色光照射下，掺杂浓度（摩尔浓度）为0.1％的薄膜电极光电流最大，与未掺杂的本征薄膜电极相比增幅达40％.I-U曲线表明，光照下，随电极电位由正到负逐渐降低，不同掺杂浓度的TiO2薄膜电极中均出现了阳极电流向阴极电流转换的现象，且Zn2+掺杂浓度可影响电极阳极电流的初始电位.另外，无光照的暗态下，各薄膜在负电位区域观察到了相似的随电位降低而迅速增大的阴极暗电流.

Study on UV Photoelectric Properties of Nanocrystalline TiO2:Zn Film Electrodes

The Zn2+-doped nanocrystalline anatase-type TiO2 film electrodes were prepared by sol-gel method. The photoelectric properties of the electrodes with different concentration of Zn2+ were studied by photocurrent action spectra and current-potential (I-U) curves. According to the action spectra,the concentration of Zn2+ can affect the photocurrent magnitude remarkably and its optimum is dependent on the particle-size of T1O2. Illuminated by 320 nm monochromatic light,Zn2+-doped TiO2 film electrode with the concentration of 0.1 mol% produced the largest photocurrent which increased 40% compared with which produced by undoped electrode. The I-U curves show that the conversion from anodic current to cathodic current occurs in all illuminated TiO2 film electrodes during the potential dropping from 1.OV to －0.4V,and the onset potential of anodic current was affected by the concentration of Zn2+. In the region of cathodic potential,in addition,similar cathodic dark current was observed for each electrode and it increased rapidly with a dropping potential.