Preparation Of TiO₂Film On The Surface Of The Microwave Discharge Electrodeless Lamp And Its Photocatalytic Activity For Degradation Of2,4-DCP

In recent years, photocatalysis degradation of chlorinated phenols made great progress in the organic wastewater. However, due to the limitations of photon transfer, contact area with photocatalyst and recovery problems, it is difficult to make any breakthroughs on the practical application. According to these problems, this experiment was investigated as the following concerned:1、TiO2films were coaded on the surface of microwave discharge electrodeless lamps by Sol-gel. The TiO2films were composed of rough TiO2nano-particle, about10nm by scanning electron microscopy. XRD was employed to examine crystallographic phase structures of TiO2film, The peaks at20of25.3°、37.8°were attributed to the signal of anatase, and the peak at44.3°was rutile.2、Spectral measurements of prepared lamps were carried out on the fiber optic spectrometer, the bands at254nm,313nm,365nm,405nm,436nm,546nm were observed. The result of UV spectrum showed that the UV irradiated by microwave discharge electrodeless lamp could be absorbed by TiO2film. The catalyst and the light source achieved the success of coupling.3、Several factors influenced the photocatalytic degradation of2,4-DCP, such as numbers of coating cycles, initial concentration, initial pH value, the concentration of Cl-, have been studied in detail. The efficiency of2,4-DCP decreased with increasing initial concentration, when the concentration was5mg/L, it could be achieved91.3%. By comparing the different concentrations of Cl-, We found that Cl-could inhibit catalytic efficiency. When the microwave power was unchanged, the efficiency of2,4-DCP degradated by the microwave discharge electrodeless lamps with TiO2films of3layers was up to81%. The best treatment effect could be obtained at pH=2.4、In this study, the comparison of spectrum launched by the microwave discharge electrodeless lamps coaded TiO2films and uncoaded was detected. And then the efficiency of2,4-DCP and TOC degradated according to photolysis and photocatalysis were observed respectively. Finally, the possible mechanism of photocatalytic degradation of2,4-DCP was investigated with high performance liquid chromatography (HPLC) and mass spectrometry (MS).