title: Prediction of (TiO2)x(Cu2O)y alloys for efficient photoelectrochemical water splitting.
abstract: The formation of (TiO(2))(x)(Cu(2)O)(y) solid-solutions is investigated using a global optimization evolutionary algorithm. First-principles calculations based on density functional theory are then used to gain insight into the electronic properties of these alloys. We find that: (i) Ti and Cu in (TiO(2))(x)(Cu(2)O)(y) alloys have similar local environments as in bulk TiO(2) and Cu(2)O except for (TiO(2))(Cu(2)O) which has some trigonal-planar Cu ions. (ii) The predicted optical band gaps are around 2.1 eV (590 nm), thus having much better performance in the absorption of visible light compared with both binary oxides. (iii) (TiO(2))(2)(Cu(2)O) has the lowest formation energy amongst all studied alloys and the positions of its band edges are found to be suitable for solar-driven water splitting applications.
authors.affiliation: Key Laboratory of Computational Physical Sciences (Ministry of Education), and Department of Physics, Fudan University, Shanghai 200433, P. R. China.
authors.forename: Heng-Rui
authors.initials: HR
authors.lastname: Liu
authors.forename: Ji-Hui
authors.initials: JH
authors.lastname: Yang
authors.forename: Yue-Yu
authors.initials: YY
authors.lastname: Zhang
authors.forename: Shiyou
authors.initials: S
authors.lastname: Chen
authors.forename: Aron
authors.initials: A
authors.lastname: Walsh
authors.forename: Hongjun
authors.initials: H
authors.lastname: Xiang
authors.forename: Xingao
authors.initials: X
authors.lastname: Gong
authors.forename: Su-Huai
authors.initials: SH
authors.lastname: Wei