Electrochemically Assisted Photocatalytic Degradation of 4-Chlorophenol by ZnFe2O4-Modified TiO2 Nanotube Array Electrode under Visible Light Irradiation
Electrochemically Assisted Photocatalytic Degradation of 4-Chlorophenol by ZnFe2O4-Modified TiO2 Nanotube Array Electrode under Visible Light Irradiation
复制标题
可见光照射下ZnFe2O4修饰TiO2纳米管阵列电极电化学辅助光催化降解4-氯苯酚
DOI：
10.1021/es100004u
复制
发表时间：
2010-07-01
影响因子：
11.4
通讯作者：
Chen, Guohua
中科院分区：
文献类型：
--
作者：
Hou, Yang;Li, Xinyong;Chen, Guohua
采用阳极氧化两步电化学工艺和一种新颖的阴极电沉积方法，随后进行退火，成功制备了具有可见光活性的排列良好的锌铁氧体/二氧化钛复合纳米管阵列（ZnFe₂O₄/TiO₂ - NTs）电极。锌铁氧体纳米粒子高度分散在TiO₂ - NTs内部，但在管口处最少。对TiO₂纳米管及衍生复合材料的结构和光学性质进行了良好的表征。复合材料在可见光区域显示出强烈的光响应以及较低的电子 - 空穴对复合率。此外，合成的ZnFe₂O₄/TiO₂ - NTs电极在可见光区域显示出比纯TiO₂ - NTs电极高得多的光电流密度。在可见光照射（420 nm <λ< 600 nm）下，对复合电极在4 - 氯苯酚和二氯乙酸分解中的电化学辅助光催化活性的显著增强进行了评估。光催化活性的提高源于ZnFe₂O₄和TiO₂之间的协同效应，这种协同效应提高了光生载流子在复合材料界面的迁移效率，并增强了可见光区域的光子捕获效率。通过测量Cl⁻浓度以及采用高效液相色谱 - 质谱联用（HPLC - MS）分析反应中间体来监测4 - 氯苯酚的降解。
A well-aligned ZnFe2O4/TiO2 composite nanotube array (ZnFe2O4/TiO2-NTs) electrode with visible-light activity was successfully prepared using a two-step electrochemical process of anodization and a novel cathodic electrodeposition method followed by annealing. The ZnFe2O4 nanoparticles were highly dispersed inside the TiO2-NTs but minimized at the tube entrances. The structure and optical properties of the TiO2 nanotubes and the derived composites have been well characterized. The composites displayed a strong photo response in the visible region and low recombination rate of the electron-hole pairs. In addition, the synthesized ZnFe2O4/TiO2 NTs electrode showed much higher photocurrent density in the visible region than pure TiO2 NTs electrode. The dramatically enhanced electrochemically assisted photocatalytic activity of the composite electrode was evaluated in the decomposition of 4-chlorophenol and dichloroacetate under visible light irradiation (420 nm < lambda < 600 nm). The improved photoelectrocatalytic (PEC) activity is derived from the synergetic effect between ZnFe2O4 and TiO2, which promoted the migration efficiency of photogenerated carriers at the interface of the composite and enhanced the efficiency of photon harvesting in the visible region. The degradation of 4-chlorophenol was monitored by measuring Cl- concentrations and analyzing reaction intermediates by high-performance liquid chromatography-mass spectroscopy (HPLC-MS).