title: Direct imaging of light emission centers in two-dimensional crystals and their luminescence and photocatalytic properties.
abstract: To fully understand the fundamental properties of light-energy-converting materials, it is important to determine the local atomic configuration of photofunctional centers. In this study, direct imaging of one- and two-Tb-atom emission centers in a two-dimensional Tb-doped Ca2Ta3O10 nanocrystal was carried. The emission centers were located at the Ca sites in the perovskite structure, and no concentration-based quenching was observed even when the emission centers were in close proximity to each other. The relative photoluminescence efficiency for green emission of the nanosheet suspension was 38.1%. Furthermore, the Tb-doped Ca2Ta3O10 nanocrystal deposited co-catalyst showed high photocatalytic activity for hydrogen production from water (quantum efficiency: 71% at 270 nm). Tb(3+) dopants in the two-dimensional crystal might have the potential to stabilize the charge separation state.
authors.affiliation: International Research Center for Hydrogen Energy, Department of Applied Chemistry, Faculty of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); PRESTO (Japan) Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan). s-ida@cstf.kyushu-u.ac.jp.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Ida
authors.forename: Shota
authors.initials: S
authors.lastname: Koga
authors.forename: Takeshi
authors.initials: T
authors.lastname: Daio
authors.forename: Hidehisa
authors.initials: H
authors.lastname: Hagiwara
authors.forename: Tatsumi
authors.initials: T
authors.lastname: Ishihara
keywords: nanosheets; photocatalysts; photoluminescence; quenching; water splitting