摘要
采用阳极氧化法和电沉积法制备出具有可见光响应的ZnFe2O4/TiO2纳米管阵列电极.用环境扫描电子显微镜(ESEM)、X-射线衍射(XRD)和透射电子显微镜(TEM)对制备的ZnFe2O4/TiO2纳米管阵列电极的表面形貌和结构进行了表征.结果表明,该方法成功地将ZnFe2O4纳米颗粒均匀分散在TiO2纳米管中,分布在管口处的较少.同时,详细讨论了反应物浓度、沉积时间、循环次数、沉积电压对ZnFe2O4/TiO2纳米管阵列电极性能的影响.通过在可见光下降解苯酚评价了复合电极的光催化活性,实验结果表明:由于ZnFe2O4和TiO2之间的协同效应,复合电极的光响应范围扩展到了可见光区域,光电催化活性提高1.5～2倍.
A well-aligned ZnFe2O4/TiO2nanotube array electrode with visible-light activity was successfully prepared using a two-step electrochemical process of anodization and a novel cathodic electrodeposition method.Its morphology and chemical composition was characterized by environmental scanning electron microscope,transmission electron microscope and X-ray diffraction.The ZnFe2O4 nanoparticles were highly dispersed inside the TiO2 nanotube but minimized at the tube entrances.The composites displayed a strong photo response in the visible region and low recombination rate of the electronhole pairs.The synthesized ZnFe2O4/TiO2 nanotube electrode showed much higher photocurrent density in the visible region than pure TiO2 nanotube electrode.In addition,we discussed the influence on the electrode properties of ZnFe2O4/TiO2 nanotube array from mass concentration sedimentary time,cycle times and sedimentary voltage.The optimal experimental condition was 0.05 mol/L Zn（NO3）3＋0.1 mol/L Fe（NO3）3,20 min 5 times and 1 V.The photocatalytic activity of the composite electrode was evaluated in the decomposition of phenol under visible light irradiation.It was found that the degradation rate increased with voltages and an increase in the activity by a factor of 1.5～2 relative to pure TiO2 nanotube was obtained under the optimal conditions.The improved photoelectrocatalytic 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.Under the visible region,the ZnFe2O4/TiO2 nanotube electrode was operated under the same experimental conditions.The results clearly show a good recycle with the degradation rate of 95% even after five repeated experiments.These results demonstrate that the ZnFe2O4/TiO2 nanotube electrode was an efficient material in utilizing solar energy for the photodecomposition of pollutants.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2013年第2期213-220,共8页
Acta Chimica Sinica
基金
精密测试技术及仪器国家重点实验室开放基金资助~~
