摘要
A novel TiO2 (anatase) containing a large amount of single electron trapped oxygen vacancies (SETOV) was prepared by dehydration of titanic acid nanotubes. This novel TiO2 contains high concentration intrinsic defects in bulk structure, while its surface still remains the stoichiometric structure to protect them. And this novel TiO2 itself has the visible light absorption without any doping, so we call it as the third generation of TiO2 . However, it is regretted that this novel TiO2 (A) only has photocatalytic activity under UV light irradiation, and was inactive for the visible light. The true reasons for this phenomenon were investigated by the transient IR absorption and photoluminescence spectra. Through constructing the foreign electron traps (PdO, PtO2 ), the photocatalytic oxidation of propylene under visible light irradiation was successfully achieved. The removal yield of propylene (C3H6 ) reached 7.6% and 28% on 2 wt.% PtO2 /novel TiO2 and 2 wt.% PdO/novel TiO2 , respectively. By comparison with the noble metal electron traps (Pt, Pd), we found that the effective foreign electron traps need to satisfy two conditions: (1) its work function should situate in the range of Eg(TiO2 ); (2) O2 adsorbes on it undissociatively. This work opens up a new route for the investiga- tion of solar-energy-available TiO2 .
A novel TiO2 （anatase） containing a large amount of single electron trapped oxygen vacancies （SETOV） was prepared by dehy- dration of titanic acid nanotubes. This novel TiO2 contains high concentration intrinsic defects in bulk structure, while its surface still remains the stoichiometric structure to protect them. And this novel TiO2 itself has the visible light absorption without any doping, so we call it as the third generation of TiO2. However, it is regretted that this novel TiO~ （A） only has photocatalytic activ- ity under UV light irradiation, and was inactive for the visible light. The true reasons for this phenomenon were investigated by the transient IR absorption and photoluminescence spectra. Through constructing the foreign electron traps （PdO, PtO2）, the pho- tocatalytic oxidation of propylene under visible light irradiation was successfully achieved. The removal yield of propylene （C3H6） reached 7.6% and 28% on 2 wt.% PtO2/novel TiO2 and 2 wt.% PdO/novel TiO2, respectively. By comparison with the noble metal electron traps （Pt, Pd）, we found that the effective foreign electron traps need to satisfy two conditions： （1） its work function should situate in the range of Eg（TiO2）; （2） 02 adsorbes on it undissociatively. This work opens up a new route for the investiga- tion of solar-energy-available TiO2.
基金
supported by the National Natural Science Foundation of China (21103042)
the Specialized Research Fund for the Doctoral Program of Higher Education (20114103120001)
the Scientific Research Foundation of Henan University (2010YBZR013)
关键词
可见光响应
二氧化钛
光催化活性
电子陷阱
本征缺陷
外国
诱导
光致发光光谱
the third generation of TiO2, titanic acid nanotubes, electron trap, oxygen vacancy, visible-light-responded photocatalysis
