title: A complex perovskite-type oxynitride: the first photocatalyst for water splitting operable at up to 600 nm.
abstract: One of the simplest methods for splitting water into H2 and O2 with solar energy entails the use of a particulate-type semiconductor photocatalyst. To harness solar energy efficiently, a new water-splitting photocatalyst that is active over a wider range of the visible spectrum has been developed. In particular, a complex perovskite-type oxynitride, LaMg(x)Ta(1-x)O(1+3x)N(2-3x)(x≥1/3), can be employed for overall water splitting at wavelengths of up to 600 nm. Two effective strategies for overall water splitting were developed. The first entails the compositional fine-tuning of a photocatalyst to adjust the bandgap energy and position by forming a series of LaMg(x)Ta(1-x)O(1+3x)N(2-3x) solid solutions. The second method is based on the surface coating of the photocatalyst with a layer of amorphous oxyhydroxide to control the surface redox reactions. By combining these two strategies, the degradation of the photocatalyst and the reverse reaction could be prevented, resulting in successful overall water splitting.
authors.affiliation: Global Research Center for Environment and Energy Based on Nanomaterials Science (GREEN), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba-city, Ibaraki, 305-0044 (Japan).
authors.forename: Chengsi
authors.initials: C
authors.lastname: Pan
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takata
authors.forename: Mamiko
authors.initials: M
authors.lastname: Nakabayashi
authors.forename: Takao
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Naoya
authors.initials: N
authors.lastname: Shibata
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ikuhara
authors.forename: Kazunari
authors.initials: K
authors.lastname: Domen
keywords: coatings; oxynitrides; perovskite phases; photocatalysis; water splitting