响应面法优化TiO2纳米管光电极制备及光电催化性能研究

为了探究采用阳极氧化法制备的TiO₂-NTs（TiO₂纳米管）光电极的光电催化性能，以单因素法考察了φ（H₂O）、w（氟化铵）、氧化温度和氧化时间4个因素对其光电催化性能的影响，并采用Box-Behnken模型的PSM（响应面法）对TiO₂-NTs的制备条件进行优化，进一步通过SEM（扫描电子显微镜）、XRD（X射线衍射）对TiO₂-NTs进行表征，研究了其在紫外光下对亚甲基蓝的光电催化效果.结果表明:①应用Box-Behnken模型可知，TiO₂-NTs最佳制备条件为φ（H₂O）43%、w（氟化铵）0.5%、氧化温度38℃、氧化时间1.72 h.此条件下制备的TiO₂纳米管光电极2 h处理亚甲基蓝的降解效率预测值为73.53%，对其光电催化能力进行验证，实际处理效率为73.2%，误差率仅为0.4%.②φ（H₂O）和w（氟化铵）对TiO₂-NTs光电极催化活性有显著影响.③SEM、XRD分析显示，TiO₂具有管状结构且分布均匀，经测量纳米管管径约为61.30~118.00 nm，平均值为83.99 nm，管壁为19.08 nm，同时部分锐钛矿相转变成金红石相.研究显示，TiO₂-NTs对亚甲基蓝有良好的光电催化效果. 

Optimized Preparation of TiO2-NTs Photoelectrode by Response Surface Method and Its Property of Photocatalytic Degradation

In order to explore the influence of preparation conditions by anodic oxidation method on the photoelectrocatalytic performance of TiO₂-NTs (TiO₂ nanotube) photoelectrode, four single factors, including φ(H₂O), w(ammonium fluoride), oxidation temperature and oxidation time were investigated by a single factor method. The preparation conditions of TiO₂-NTs by anodic oxidation was optimized according to the Box-Behnken model of the response surface method. SEM (scanning electron microscope) and XRD (X-ray diffraction) were used to characterize the TiO₂-NTs catalyst, and the photoelectrocatalytic effect of these photoelectrodes on methylene blue under ultraviolet light was further studied. The results showed that:(1) According to the Box-Behnken model, the optimum preparation conditions were 43% water content, 0.5% of ammonium fluoride, oxidation temperature 38℃ and oxidation time 1.72 h. The predicted value of methylene blue degradation ratio was 73.53% after 2 h treatment of the TiO₂-NTs. The photoelectrocatalytic ability was verified and the actual treatment effect was 73.2%. The error rate was only 0.4%. (2) φ(H₂O) and w(ammonium fluoride) significantly affected the photoelectrocatalytic property of TiO₂-NTs. (3) SEM and XRD analyses showed that TiO₂ had a tubular structure and a uniform distribution. The diameter of the nanotubes was about 61.30-118.00 nm with average diameter of 83.99 nm. The tube wall was about 19.08 nm. At the same time, anatase was partially transformed into rutile. The results showed that TiO₂-NTs had a good photoelectrocatalytic effect on the treatment methylene blue.