Fe_2O_3/TiO_2纳米管的制备及其光电催化降解染料废水性能

Fabrication of Fe_2O_3/TiO_2 Nanotube Electrode and Its Photoelectrocatalytic Performance in Dye Wastewater Degradation

采用阴极电沉积和阳极氧化法制备了Fe2O3改性TiO2纳米管(Fe2O3/TiO2-NTs)电极,运用场发射扫描电子显微镜、透射电子显微镜、X射线衍射和紫外-可见漫反射光谱等手段对其进行了表征,考察了其光电化学性能,并研究了复合电极光电催化降解甲基橙染料废水的反应性能.结果表明,Fe2O3的负载成功地将TiO2-NTs的光响应区间拓宽到可见光区域,Fe2O3/TiO2-NTs复合电极的光电流密度达到TiO2-NTs电极的3倍.在光电催化反应中,Fe2O3/TiO2-NTs复合电极对甲基橙的脱色效果明显优于TiO2-NTs电极,以Fe2O3/TiO2-NTs为阳极,光照5min,甲基橙溶液的脱色率可达90%以上.

The Fe203/TiO2 nanotubes electrode was prepared using cathodically electrochemical deposition and anodic oxidation method. The properties of the composite electrode were characterized by scanning electron microscopy, transmission electronic microscope, X-ray diffraction, and UV-Vis diffuse reflectance spectroscopy. The decolorization of methyl orange was investigated using the composite electrode as a photoanode. The results indicated that Fe203 nanoparticles were uniformly dispersed on the surface of TiO： nanotubes electrode. The adsorption edge of the composite electrode exhibited a red shift compared with the pure TiO2 nanotubes electrode. In addition, Fe2OflTiO2 nanotubes electrode showed higher current density than TiO2 nanotubes electrode under irradiation. It indicated that the metal oxide modifi- cation successfully broadened the absorption spectrum of TiO2 nanotubes to the visible light region. Moreover, it was in favor of the separa- tion of photo-induced electron-hole pairs. The Fe203/TiO2 nanotubes electrode performed higher photoelectrocatalytic activity for the degra- dation of methyl orange. Furthermore, it was found that methyl orange had a higher decolorization rate under the acidic condition. When the initial pH value was 3, the decolorization rate of methyl orange solution could reach 91.7% under the light irradiation for 5 min.