Rationalizing long-lived photo-excited carriers in photocatalyst (La5Ti2CuS5O7) in terms of one-dimensional carrier transport

Autor: Yohichi Suzuki, Rupashree Balia Singh, Kazunari Domen, Guijun Ma, Kazuhiko Seki, Akihiro Furube, Takashi Hisatomi, Hiroyuki Matsuzaki
Rok vydání: 2016
Předmět:
Zdroj: Chemical Physics. 476:9-16
ISSN: 0301-0104
DOI: 10.1016/j.chemphys.2016.07.012
Popis: The semiconductor La 5 Ti 2 CuS 5 O 7 (LTC) is a potential photocatalyst capable of operating under visible light irradiation and behaves both as a photocathode and anode when embedded onto metal layers. Time-resolved diffuse reflectance (TRDR) measurements were carried out on LTC powder and LTC deposited on Au as the back contact using the particle-transfer method. Results of TRDR measurements of powdered LTC indicated the existence of long-lived photo-excited carriers, and suggested the existence of a mechanism for preventing carrier loss in LTC. Prior research has reported that LTC has a rod-shaped crystal structure and that electrons and holes are transported through different, spatially separated channels. Based on this, we introduced a one-dimensional carrier transport model. By analyzing TRDR data, we extracted material parameters such as the diffusion coefficient of LTC. Theoretical results indicated that a micron-sized LTC particle would be preferable if carriers trapped at the top-surface do contribute to photocatalytic gas generation.
Databáze: OpenAIRE