超微粉二氧化钛和掺杂三氧化二铁光催化剂的表面光电压谱研究

基于表面光伏效应测得的表面光电压谱在半导体表面化学物理的研究中早已获得极为广泛的应用。近年来,我们实验室成功地将这一技术应用于复相光催化的研究中^1,2],如发现表面光伏信号是半导体多晶粉末光催化剂具有活性的必要条件,光电压信号愈强光催化活性愈高,而且二者存在半定量的关系。这些结果启发我们,表面光伏技术有可能发展成为一种快速评估光催化剂的有效方法。

A STUDY OF TITANIA AND DOPED IRON TRIOXIDE ULTRAFINE POWDERS BY SURFACE PHOTOVOLTAGE SPECTROSCOPY

In this paper, the TiO₂ and Fe₂O₃:Mg:Si ultrafine powders were synthesized by the hydrolysis of metal alkoxides, and the depedence of their photocatalytic conversion efficiency to SO₃^2- aqueous solution on their surface photovoltaic responces was studied.It was found that, because the ultrafine particles are small in diameter, the light-induced electrons and holes are very easy to be trapped.Therefore, the results are different from usual powder photocatalysts.i.e., the weaker the surface photo-voltage signal, the higher the photocatalytic activity.