College of Chemistry, Jilin University, Changchun 130012, PR China.
Phys Chem Chem Phys. 2013 Sep 14;15(34):14262-9. doi: 10.1039/c3cp51850g. Epub 2013 Jul 22.
The transfer properties of the photogenerated charge carriers in TiO2 nanotube arrays (TNAs) and ZnFe2O4 modified TiO2 nanotube arrays (ZFO-TNAs) were investigated by surface photovoltage phase spectra. The modification of ZnFe2O4 on TNAs will lead to a new process of photogeneration of charge carriers. When irradiated with UV or visible light, before ZnFe2O4 modification photogenerated holes can transfer to the surface of TNAs; while after ZnFe2O4 modification, a process of photogenerated electrons transferring to the surface occurred. The different detected photogenerated charge transfer processes agree well with the photocatalytic reduction of Cr(VI) and the degradation of methyl orange experiments, which confirmed that the photogenerated holes transferring to the surface of the TNAs or ZFO-TNAs were beneficial for the reactions of photocatalytic reduction and electrons transferring to the surface were beneficial for photocatalytic degradation.
通过表面光电压相谱研究了 TiO2 纳米管阵列（TNAs）和 ZnFe2O4 修饰的 TiO2 纳米管阵列（ZFO-TNAs）中光生载流子的输运性质。ZnFe2O4 对 TNAs 的修饰会导致载流子光生的新过程。在紫外光或可见光照射下，ZnFe2O4 修饰前，光生空穴可以转移到 TNAs 的表面；而 ZnFe2O4 修饰后，发生了光生电子转移到表面的过程。不同检测到的光生电荷转移过程与 Cr(VI)的光催化还原和甲基橙的降解实验很好地吻合，这证实了光生空穴转移到 TNAs 或 ZFO-TNAs 的表面有利于光催化还原反应，而电子转移到表面有利于光催化降解。
