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Rendering Photoreactivity to Ceria: The Role of Defects
Author(s) -
Yang Chengwu,
Yu Xiaojuan,
Pleßow Philipp N.,
Heißler Stefan,
Weidler Peter G.,
Nefedov Alexei,
Studt Felix,
Wang Yuemin,
Wöll Christof
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201707965
Subject(s) - rutile , photochemistry , cerium oxide , dissociation (chemistry) , oxide , rendering (computer graphics) , decomposition , band gap , spectroscopy , cerium , infrared spectroscopy , chemistry , absorption spectroscopy , materials science , inorganic chemistry , optoelectronics , optics , computer graphics (images) , physics , organic chemistry , quantum mechanics , computer science
The photoreactivity of ceria, a photochemically inert oxide with a large band gap, can be increased to competitive values by introducing defects. This previously unexplained phenomenon has been investigated by monitoring the UV‐induced decomposition of N 2 O on well‐defined single crystals of ceria by using infrared reflection‐absorption spectroscopy (IRRAS). The IRRAS data, in conjunction with theory, provide direct evidence that reducing the ceria(110) surface yields high photoreactivity. No such effects are seen on the (111) surface. The low‐temperature photodecomposition of N 2 O occurs at surface O vacancies on the (110) surface, where the electron‐rich cerium cations with a significantly lowered coordination number cause a local lowering of the huge band gap (ca. 6 eV). The quantum efficiency of strongly reduced ceria(110) surfaces in the photodecomposition of N 2 O amounts to 0.03 %, and is thus comparable to that reported for the photooxidation of CO on rutile TiO 2 (110).