The kinetics of photocatalysis can be usually described by Langmiur Hinshelwood adsorption expression. The adsorption can be greatly influenced by the surface properties of photocatalyst. Triple layer model (TLM) was ...The kinetics of photocatalysis can be usually described by Langmiur Hinshelwood adsorption expression. The adsorption can be greatly influenced by the surface properties of photocatalyst. Triple layer model (TLM) was chosen to describe the surface adsorption of TiO 2 based on electrical double layer (EDL) theory at the TiO 2/water interface. And through the potentiometric titration the parameters of TLM were determined by the extrapolation method and Fiteql3.1 software. The results show that surface complexation dominates the surface charge and the numerical calculation fits the experiment data satisfactorily.展开更多
Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO...Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO 2 and iron deposited TiO 2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe 3+ and Fe 2+ are present on the surface of 0.5% iron deposited TiO 2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe 3+ /Fe 2+ couple seems plausible, but Fe 2+ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO 2, because iron deposited traps photo generated electrons and holes. The fluorescence intensity order of TiO 2 and iron deposited TiO 2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO 2 and iron deposited TiO 2, from low to high.展开更多
文摘The kinetics of photocatalysis can be usually described by Langmiur Hinshelwood adsorption expression. The adsorption can be greatly influenced by the surface properties of photocatalyst. Triple layer model (TLM) was chosen to describe the surface adsorption of TiO 2 based on electrical double layer (EDL) theory at the TiO 2/water interface. And through the potentiometric titration the parameters of TLM were determined by the extrapolation method and Fiteql3.1 software. The results show that surface complexation dominates the surface charge and the numerical calculation fits the experiment data satisfactorily.
文摘Iron deposited TiO 2 was prepared by photo reducing ferric ions. The photocatalytic activity of methylene blue degradation was enhanced after TiO 2 was deposited with iron, and the optimum n (Fe)/ n (Ti) is 0.25%. TiO 2 and iron deposited TiO 2 are anatase and rutile, and anatase is the dominant crystalline phase. In all samples, the XRD patterns indicate that there are no characteristic peaks of iron to be detected. XPS confirms that Fe 3+ and Fe 2+ are present on the surface of 0.5% iron deposited TiO 2, however they are not susceptible to XRD detection. The thermodynamics analysis shows that the alternative possibility of reduction from the Fe 3+ /Fe 2+ couple seems plausible, but Fe 2+ can not be reduced to Fe. The fluorescence intensity weakens after iron is deposited on TiO 2, because iron deposited traps photo generated electrons and holes. The fluorescence intensity order of TiO 2 and iron deposited TiO 2, from strong to weak, is in good agreement with that of photocatalytic reactiveness TiO 2 and iron deposited TiO 2, from low to high.
