| Sulfur-doped titanium dioxide, nitrogen-doped titanium dioxide and N,S-codoped titanium dioxide were all prepared by a simple sol-gel method using tetrabutyl titanate, potassium persulfate and hydroxylamine hydrochloride as precursors. Photocatalytic degradation of waste water from eosin solution have been researched by taking doped TiO2 as catalysts and visible light as light source. The procedures and results are as follows:FTIR, XRD, SEM and particles size analysis were applied to characterize the samples.The results showed that doped titanium dioxide samples were successfully synthesized. Firstly , the influences of calcine temperature and doping amounts on visible light activity were studied. When the sulfur-dopant content was 2%,nitrogen-dopant content was 6%, and the calcine temperature was 400℃,the visible-light photocatalytivity was the best.The main factors involved in the experiment were pH, reacton time, initial concentration of Eosin Y and TiO2 dosage. The optimal conditions of treatment of Eosin Y were found by means of orthogonal experiment design and the uniform experimental design. The results showed that: when the dosage of sulfur-doped titanium dioxide was 0.7g/L, pH=5, initial concentration of Eosin Y was 11mg/L, the photocatalytic reaction time was 50min, decolorization rate of Eosin Y solution is 97.05 %; when the dosage of nitrogen-doped titanium dioxide was 4.2g/L, pH=4, initial concentration of Eosin Y was 21mg/L, the photocatalytic reaction time was 80min, decolorization rate of Eosin Y solution is 99.5%; when the dosage of N,S-codoped titanium dioxide was 1.8g/L, pH=4, initial concentration of Eosin Y was 17mg/L, the photocatalytic reaction time was 17min, decolorization rate of Eosin Y solution was 99.4 %.The kinetics of photocatalytic degradation has been studied. We studied the relationship between the reaction rate and dosage of catalysts, initial concentration of Eosin Y, and pH.And we have also established muti-factor photocatalytic kinetic model. |
PDF Full Text Request