Study On Photodegradation Of TCB Using Microwaved TiO₂Doped Iron And Zinc Chromium

The preparation of three kinds of transition metal ion (Fe3+, Zn2+and Cr3+) dopedTiO2catalyst and modification of a transition metal ion doped TiO2catalysts undermicrowave radiation is optimized in this paper. To evaluate the catalytic activity ofdifferent catalysts, experiments were carried out with methyl orange as a simulationof the environmental pollution to investigate the effect of the light degradation andthe rate of the photocatalytic reaction of the nanotitania prepared through differentmethods. The transition metal doping nanotitania photocatalyst after microwavemodification was finally applied to the light degradation of three isomerides oftrichlorobenzene and the effect of the photocatalystic reaction was investigated.The photodegradation effect of TiO2photocatalysts doped three kinds oftransition metal ions upon methyl orange indicates that, the catalytic activity of theTiO2photocatalyst increases in some degree by the doping of transition metal ionsFe3+、 Zn2+and Cr3+. The increasement of the catalytic activity of the TiO2photocatalyst follows the order: Fe3+ions> Zn2+ions and Cr3+ions. This is mainlybecause Fe3+,comparing to Zn2+and Cr3+, is easier to form plenty of electron and holecapture depression on TiO2while doped into it. The experimental results show thatthe catalytic activity of the photocatalyst is the highest when the ratio of Fe3+is0.1%,and its photodegradation effect upon methyl orange is the best and the photocatalyticreaction rate is the highest. Selecting the TiO2photocatalyst doped0.1%Fe3+forfurther microwave radiation experiments; the results indicate that, the rate of thephotodegradation effect is the highest when the dosage is1g/L. As the microwavepower increases slowly to400W, the crystal particle size of TiO2decreases, thespecific surface area of it increases, and the catalytic activity of the photocatalyst isthe highest. Fe3+ions move out of TiO2crystals from the inside of them with thefurther increase of microwave power, leading to an increase in the degree ofcrystallinity and decrease in the catalytic activity. The degradation effect of TiO2photocatalysts doped0.1%Fe3+under different period of microwave radiation uponmethyl orange indicates that, the photodegradation effect rate is the highest when theperiod lasts for8min. The results show that the Fe3+doped TiO2photocatalysts (thedoped amount0.1%) has the best photocatalytic activity under the circumstance of 400W microwave power and8min radiation. The photodegradation experiments ofthree kinds of Trichloro Benzene using photocatalysts prepared in optimized methodsindicates that, comparing the TiO2photocatalysts doped0.1%Fe3+and regular TiO2photocatalysts, photocatalysts prepared under the optimum conditions withmicrowave radiation has higher photocatalytic activity, and they have betterphotodegradation effect upon Trichloro Benzene.