Resuscitating Of Nano-TiO₂ By Soft-mechanochemical Ion Exchange Method

In the thesis, nano-TiO₂ was resuscitated by soft-mechanochemical ion exchange method. Methyl-orange was made as degradation object. COD, chroma and UV-Vis spectrophotometer were used as analysis methods in the experiments.By comparing photocatalytic activity of nano-TiO₂ before and after resuscitating, the effect of resuscitating was observed, the principle of resuscitating was analyzed.Soft-mechanochemical ion exchange method can resuscitate nano-TiO₂ which had lost activation. In the experimentation of dynamic UV-photocatalytic reaction, the removing percentage of COD is renewed from 41% to 65%, which is approach to 68% of the fresh nano-TiO₂. The removing percentage of chroma is renewed from 55% to 84%, which is approach to 87% of the fresh nano-TiO₂.This method can remove unfirm and firm absorbents which absorbed on the surface of nano-TiO₂. The removing percentage of the resuscitated nano-TiO₂ to chroma during fourth photocatalytic process is 87%, which is higher than 65% during eighth photocatalytic process of the fresh nano-TiO₂. The removing percentage of the resuscitated nano-TiO₂ to chroma during teneh photocatalytic process is 37%, which is higher than 35% during tenth photocatalytic process of the fresh TiO₂.This method also can resuscitate nano-TiO₂ many times. In the experiment , the degressive extent of nano-TiO₂ resuscitated one time photocatalyzed methyl-orange one time and four times was 24%, that of nano-TiO₂ resuscitated tow times was 26%, that of nano- TiO₂ resuscitated three times was 32%, all were lower than 42% of fresh nano-TiO₂'s. This method offers a method to keep higher photocatalytic activity in long time. In the experiment, nano-TiO₂ photocatalyzed methyl-orange one time was resuscitated. The removing percentages of the resuscitated nano-TiO₂ to chroma all were about 89%. The removing percentages to COD all were above 80%. Those approached to the fresh nano-TiO₂'s.The resuscitating process is what mechanochemical and ion exchange work together to resuscitate nano-TiO₂.Activity of nano-TiO₂ can be resuscitated and reused by soft-mechanochemical ion exchange method. The resuscitating conditions should be optimized and used in every photocatalytic process in order to purify the wastewater deeply.