The TiO2 thin films were prepared on the surface of soda lime glass via sol gel method, and calcined at 500℃ for 2h. The as calcined TiO2 thin films were treated in 1mol·L-1 H2SO4 aqueous solution for 24h, after...The TiO2 thin films were prepared on the surface of soda lime glass via sol gel method, and calcined at 500℃ for 2h. The as calcined TiO2 thin films were treated in 1mol·L-1 H2SO4 aqueous solution for 24h, after that the thin films were heat treated at 100℃ and 500℃ for 0.5h, respectively. The structures and photocatalytic activity of TiO2 thin films before and after surface acid treatment were characterized and evaluated by UV Vis, SEM, TEM and XPS and photocatalytic decoloration of methyl orange aqueous solution, respectively. It was found that after TiO2 thin films were treated in H2SO4 solution and calcined at 100℃ and 500℃, the content of sodium ions in the TiO2 thin films decreases and the photocatalytic activity of the thin films increases obviously. Moreover, the films show the highest photocatalytic activity at 500℃.展开更多
Titanium dioxide nano particles (for example, P25, Germany, Degussa) have been internationally used as an effective photo catalyst for many years. In this paper, characterization of P25, photo degradation ability as w...Titanium dioxide nano particles (for example, P25, Germany, Degussa) have been internationally used as an effective photo catalyst for many years. In this paper, characterization of P25, photo degradation ability as well as its life time has been systematically studied by employing methyl orange as a model pollutant. Many factors such as the pH value, pre treatment have been investigated. Just like other nanometer sized or ordinary Anatase TiO2, the catalyst performs better at an optimal pH value. Pre treatment of the catalyst also enhances the photo catalytic ability. And the P25 have shown rather good life time. The degradation products have been characterized by UV, mass and Raman spectrum.It is found that although the P25 photo catalyst has shown excellent decolourization ability, it is still difficult to degrade the methyl orange into small molecule, such as CO2 and H2O. Low power ultraviolet lamps (9W, 254nm) have been used throughout. A comparison experiment has been carried out under natural sunlight, and the results have shown that natural sunlight (With temperature below10℃) could provide even more energy than that of the adopted ultraviolet lamp, which have proved P25 a rather promising photo catalyst for practical application in environment field under natural surrounding. The obtained results may serve as a valuable reference for the evaluation and preparation of high quality TiO2 photo catalyst.展开更多
TiO2/glass film was prepared by a solgel method with titanium tetrabutoxide as precursor,and used in photocatalytic degradation of 4Chlorophenol(4CP)in aqueous solution.The crystal type and size of TiO2 in f...TiO2/glass film was prepared by a solgel method with titanium tetrabutoxide as precursor,and used in photocatalytic degradation of 4Chlorophenol(4CP)in aqueous solution.The crystal type and size of TiO2 in film prepared in different experimental conditions were characterized by using XRD.The experiments indicated that the TiO2 particles in different film appear regular anatase structure with size about 833nm after heating treatment at 500℃ temperature,and the film coated 5 layers of TiO2 sol in the case of higher(pH≥10)and lower pH value(pH≤2) showed a higher catalytic activity.The relationship between initial 4CP concentration(C0) and reaction rate(r0) follow LangmuirHinshelwood equation,and the photocatalytic degradation of 4CP(C0≤07mmol·L-1)can be expressed by first order kinetics.展开更多
文摘The TiO2 thin films were prepared on the surface of soda lime glass via sol gel method, and calcined at 500℃ for 2h. The as calcined TiO2 thin films were treated in 1mol·L-1 H2SO4 aqueous solution for 24h, after that the thin films were heat treated at 100℃ and 500℃ for 0.5h, respectively. The structures and photocatalytic activity of TiO2 thin films before and after surface acid treatment were characterized and evaluated by UV Vis, SEM, TEM and XPS and photocatalytic decoloration of methyl orange aqueous solution, respectively. It was found that after TiO2 thin films were treated in H2SO4 solution and calcined at 100℃ and 500℃, the content of sodium ions in the TiO2 thin films decreases and the photocatalytic activity of the thin films increases obviously. Moreover, the films show the highest photocatalytic activity at 500℃.
文摘Titanium dioxide nano particles (for example, P25, Germany, Degussa) have been internationally used as an effective photo catalyst for many years. In this paper, characterization of P25, photo degradation ability as well as its life time has been systematically studied by employing methyl orange as a model pollutant. Many factors such as the pH value, pre treatment have been investigated. Just like other nanometer sized or ordinary Anatase TiO2, the catalyst performs better at an optimal pH value. Pre treatment of the catalyst also enhances the photo catalytic ability. And the P25 have shown rather good life time. The degradation products have been characterized by UV, mass and Raman spectrum.It is found that although the P25 photo catalyst has shown excellent decolourization ability, it is still difficult to degrade the methyl orange into small molecule, such as CO2 and H2O. Low power ultraviolet lamps (9W, 254nm) have been used throughout. A comparison experiment has been carried out under natural sunlight, and the results have shown that natural sunlight (With temperature below10℃) could provide even more energy than that of the adopted ultraviolet lamp, which have proved P25 a rather promising photo catalyst for practical application in environment field under natural surrounding. The obtained results may serve as a valuable reference for the evaluation and preparation of high quality TiO2 photo catalyst.
文摘TiO2/glass film was prepared by a solgel method with titanium tetrabutoxide as precursor,and used in photocatalytic degradation of 4Chlorophenol(4CP)in aqueous solution.The crystal type and size of TiO2 in film prepared in different experimental conditions were characterized by using XRD.The experiments indicated that the TiO2 particles in different film appear regular anatase structure with size about 833nm after heating treatment at 500℃ temperature,and the film coated 5 layers of TiO2 sol in the case of higher(pH≥10)and lower pH value(pH≤2) showed a higher catalytic activity.The relationship between initial 4CP concentration(C0) and reaction rate(r0) follow LangmuirHinshelwood equation,and the photocatalytic degradation of 4CP(C0≤07mmol·L-1)can be expressed by first order kinetics.
