Premium
Direct Observation of Interfacial Charge Transfer between Rutile TiO 2 and Ultrathin CuO x Film by Visible‐Light Illumination and Its Application for Efficient Photocatalysis
Author(s) -
Osako Kazutaka,
Matsuzaki Kosuke,
Susaki Tomofumi,
Ueda Shigenori,
Yin Ge,
Yamaguchi Akira,
Hosono Hideo,
Miyauchi Masahiro
Publication year - 2018
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201800669
Subject(s) - rutile , photocatalysis , materials science , absorption edge , visible spectrum , photochemistry , absorption (acoustics) , analytical chemistry (journal) , band gap , optoelectronics , chemistry , catalysis , biochemistry , organic chemistry , composite material , chromatography
A well‐defined interface between CuO x film and TiO 2 is constructed as a model for elucidating the interfacial charge transfer (IFCT) process that occurs during photocatalysis. Spectroscopic analysis revealed strong blue light absorption at 2.7 eV in this film system. Based on photoemission spectroscopy and the UV‐visible absorption analysis, the band offset of CuO x and TiO 2 was investigated, and the observed blue absorption at 2.7 eV could be explained by an IFCT process, in which electrons in the valence band of TiO 2 were excited into the conduction band of the ultrathin CuO x film. Furthermore, the IFCT transition was found to strongly depend on the crystal face of TiO 2 , as the IFCT absorption was significantly increased in the ultrathin CuO x film coated over the rutile TiO 2 (110) substrate. Probe reduction and oxidation reactions were also used to investigate the charge transport process and determine photocatalytic reaction sites, which were located around a few nanometers‐scale region from the edge of the ultrathin CuO x and TiO 2 . The present findings provide a powerful method for the development of efficient visible‐light sensitive photocatalysts based on the IFCT concept.