Preparation and photocatalytic performance of Cs⁺/Sr²⁺-doped nano-sized TiO₂

À´Ô´ÆÚ¿¯£ºÖÐÄÏ´óѧѧ±¨(Ó¢ÎÄ°æ)2009ÄêµÚz1ÆÚ

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ÎÄÕÂÒ³Â룺282 - 285

Key words£ºphotocatalysis£» titanium dioxide£» cesium£» strontium£» doping

Abstract: The un-doped TiO2 and Cs⁺/Sr²⁺-doped TiO₂ nanometer particles were prepared by sol-gel method using tetrabutyl titanate (Ti(OC₄H₉)₄) as TiO₂ precursor,and characterized with X-ray diffraction (XRD) and UV-Vis absorption spectra (UV-Vis). The photocatalytic activities of these samples were investigated by the photocatalytic degradation of methyl orange in aqueous suspension under 300 W medium pressure mercury lamp irradiation. The results show that the growth of crystallite size can be controlled effectively for the Cs⁺/Sr²⁺-doped TiO₂,and crystal phase transformation of nano-sized TiO₂ is retarded from anatase structure to rutile structure while using the proper doping concentration of Cs⁺/Sr²⁺. It is pure anatase of high photocatalytic activity for Cs⁺/Sr²⁺-doped nano-sized TiO₂ prepared at 600 ¡æ for 2 h. The average crystal sizes of un-doped TiO₂,0.1% Cs⁺-doped TiO₂ and 0.3% Sr²⁺-doped TiO₂ are 21.3,13.1 and 10.8 nm,respectively. Moreover,the doping TiO₂ can extend the light response to the visible region at 400-600 nm. By measuring their photocatalytic degradation rate of methyl orange solution,the results indicate thatCs⁺/Sr²⁺ -doped TiO₂ samples are found to improve photocatalytic degradation activity of TiO₂ markedly,and the optimal doping concentration is determined to be 0.1% and 0.3% for Cs⁺ and Sr²⁺,respectively. Photocatalytic degradation rate of Cs⁺/Sr²⁺-doped nano-sized TiO₂ can be 15%-25% higher than that of un-doped TiO₂ under the same condition.