Electron-Hole Recombination Time at TiO2 Single-Crystal Surfaces: Influence of Surface Band Bending

被引：225

作者：

Ozawa, Kenichi ^{[1
]}

Emori, Masato ^{[2
]}

Yamamoto, Susumu ^{[3
]}

Yukawa, Ryu ^{[3
]}

Yamamoto, Shingo ^{[3
]}

Hobara, Rei ^{[3
]}

Fujikawa, Kazushi ^{[3
]}

Sakama, Hiroshi ^{[2
]}

Matsuda, Iwao ^{[3
]}

机构：

[1] Tokyo Inst Technol, Dept Chem & Mat Sci, Meguro Ku, Tokyo 1528551, Japan

[2] Sophia Univ, Dept Phys, Chiyoda Ku, Tokyo 1028554, Japan

[3] Univ Tokyo, Inst Solid State Phys, Kashiwa, Chiba 2778581, Japan

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2014年 / 5卷 / 11期

关键词：

CHARGE-CARRIER DYNAMICS; ANATASE; LASER;

D O I：

10.1021/jz500770c

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：

Photocatalytic activity is determined by the transport property of photoexcited carriers from the interior to the surface of photocatalysts. Because the carrier dynamics is influenced by a space charge layer (SCL) in the subsurface region, an understanding of the effect of the potential barrier of the SCL on the carrier behavior is essential. Here we have investigated the relaxation time of the photoexcited carriers on single-crystal anatase and rutile TiO2 surfaces by time-resolved photoelectron spectroscopy and found that carrier recombination, taking a nanosecond time scale at room temperature, is strongly influenced by the barrier height of the SCL. Under the flat-band condition, which is realized in nanometer-sized photocatalysts, the carriers have a longer lifetime on the anatase surface than the rutile one, naturally explaining the higher photocatalytic activity for anatase than rutile.

引用

页码：1953 / 1957

页数：5

共 30 条

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