THERMAL AND PHOTO-STIMULATED DESORPTION OF CHEMISORBED OXYGEN MOLECULES FROM TITANIUM-DIOXIDE SURFACES

被引：51

作者：

YANAGISAWA, Y

OTA, Y

机构：

来源：

SURFACE SCIENCE | 1991年 / 254卷 / 1-3期

关键词：

D O I：

10.1016/0039-6028(91)90619-4

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Thermal desorption (TD) and photo-stimulated desorption (PSD) studies of O-18(2) pre-adsorbed TiO2 powders have been carried out under high-temperature UHV treatment. At peak temperatures (T(p)) 180 and 470 K with a shoulder at about 520 K, O-18(2) TD's are observed. TD of O-16 O-18 with a small amount of O-16(2) is observed at 530 K, indicating that oxygen isotope exchange occurs between O-18(2) gas and defective TiO2 surfaces. By UV illumination with the threshold energy of 3.0 eV, O-18(2) PSD takes place at room temperature, which results in the decrease of an O-18(2) TD peak. PSD rate decays as t-n with n about 0.5, where t is the illumination time. A plausible PSD mechanism is discussed based on the substrate-dependent process induced by photons with band-gap energy.

引用

页码：L433 / L436

页数：4

共 9 条

[1] REACTIONS INVOLVING ELECTRON-TRANSFER AT SEMICONDUCTOR SURFACES .11. OXYGEN ISOTOPE EXCHANGE VIA PHOTOINITIATED R1, R0 AND PLACE EXCHANGE PROCESSES ON ZNO AND TIO-2 [J].