微波Sol-Gel制备TiO2的研究及其对活性艳红X-3B的降解

采用微波Sol-Gel法在石英表面制备了负载型TiO2光催化剂,通过紫外吸收光谱和X衍射分析表征了TiO2溶胶的变化过程及锐钛型TiO2的生成。以活性艳红X-3B为模拟污染物进行光催化降解,探讨了微波功率、反应温度和反应时间对微波Sol-Gel法制备TiO2光催化活性的影响。由因素试验确定了最佳工艺条件:微波功率400W,反应温度90℃,反应时间2min。在此条件下制备的TiO2催化剂对活性艳红X-3B溶液进行光催化降解,反应30 min的脱色率达93%,TOC去除率为55%。采用中空纤维膜三相液相微萃取-毛细管电泳(HF-LLLME-CE)联用技术对降解生成的小分子有机物进行了测定。

Preparation of TiO2 with the microwave radiation Sol - Gel method and photo-catalytic oxidation of C.I.Reactive Red 2

The present paper intends to introduce our research on how to prepare TiO2 with the microwave radiation sol-gel method and the photo-catalytic oxidation of C.I.Reactive Red 2 deposited on the quartz surfaces.In our research,we have adopted UV-Vis spectroscopic technique for monitoring the changing progress of TiO2 sol,and analyzed X diffraction so as to characterize the formation of TiO2.We have also done a series of experiments to test the impact of microwave power,the reaction temperature and reaction time on the TiO2 sol quality.The results of our experiments have shown that the TiO2 prepared by the above said method is endowed with higher photocatalytic activity and stronger oxidative ability to the C.I.Reactive Red 2.The optimal condition of the preparation of TiO2 is at the microwave power of 400 W,at the reaction temperature 90 ℃,and the reaction time 2 min.And,in turn,the TiO2 prepared with the above method as the catalyst in the experiment of photocatalytic oxidation of the C.I.Reactive Red 2,it can be found that the decolorization rate of the simulated sewage can be made as high as to 93% with the removing rate of TOC being 55% after 30 min photocatalytic reaction.In addition,we have also validated the three-liquid-phase microextraction of the hollow fiber membrane coupled with capillary electrophoresis(HF-LLLME-CE) method when analyzing the micro-particles’ organic compounds resulted from the TiO2 photocatalytic oxidation of the C.I.Reactive Red 2.The recommended conditions of the hollow fiber membrane of the three-liquid-phase micro-extraction are extraction solvent,Tri-Butyl-Phosphate(TBP),the donor phase pH=2.5,the receptor phase(with pH of 12.0) and extraction time(35 min),with no need to add salt.And the capillary electrophoresis proves to be able to run at the PDA detection wavelength 200 nm,at the injection pressure of 3.45 kPa,the injection time of 10 s and separation voltage at-12 kV,under the operating buffer of 230 mmol·L-1 NaH2PO4,115 mmol·L-1 Na2B4O7 and 0.5 mmol·L-1 CTAB.And,finally,under the above-said conditions,we have succeeded in finding five organic acids,that is,the oxalic acid,succinic acid,citric acid,malic acid, lactic acid,with the spiked recoveries ranged from 87% to 95%.