Local charge carrier dynamics of a particulate Ga-doped La5Ti2Cu0.9Ag0.1O7S5 photocatalyst and the impact of Rh cocatalysts. Issue 29 (13th July 2022)

• Record Type: Journal Article
• Authors: Chugenji, Tatsuya; Pan, Zhenhua; Nandal, Vikas; Seki, Kazuhiko; Domen, Kazunari; Katayama, Kenji
• Is Part Of: Physical chemistry chemical physics. Volume 24:Issue 29(2022)
• Page Start: 17485
• Page End: 17495
• Publication Date: 2022-07-13
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d2cp02808e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Photocatalytic charge carriers (electrons, holes, electrons at cocatalysts) were selectively separated based on the charge carrier dynamics. Abstract : Visible-light responsive photocatalytic materials are expected to be deployed for practical use in photocatalytic water splitting. One of the promising materials as a p-type semiconductor, oxysulfides, was investigated in terms of the local charge carrier behavior for each particle by using a home-built time-resolved microscopic technique in combination with clustering analysis. We could differentiate electron and hole trapping to the surface states and the following recombination on a micron-scale from the nanosecond to microsecond order. The map of the charge carrier type revealed that charge trapping sites for electrons and holes were spatially separated within each particle/aggregate. Furthermore, the effect of the rhodium cocatalyst was recognized as a new electron pathway, trapping to the rhodium site and the following recombination, which was delayed compared with the original electron recombination process. The Rh effect was discussed based on the phenomenological simulation, revealing a possible reason for the decay was due to the anisotropic diffusion of charge carriers in oxysulfides or the interfacial energy barrier at the interface.