title: Effect of the Hydrogen Bond in Photoinduced Water Dissociation: A Double-Edged Sword.
abstract: Photoinduced water dissociation on rutile-TiO2 was investigated using various methods. Experimental results reveal that the water dissociation occurs via transferring an H atom to a bridge bonded oxygen site and ejecting an OH radical to the gas phase during irradiation. The reaction is strongly suppressed as the water coverage increases. Further scanning tunneling microscopy study demonstrates that hydrogen bonds between water molecules have a dramatic effect on the reaction. Interestingly, a single hydrogen bond in water dimer enhances the water dissociation reaction, while one-dimensional hydrogen bonds in water chains inhibit the reaction. Density functional theory calculations indicate that the effect of hydrogen bonds on the OH dissociation energy is likely the origin of this remarkable behavior. The results suggest that avoiding a strong hydrogen bond network between water molecules is crucial for water splitting.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Wenshao
authors.initials: W
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Xianchi
authors.initials: X
authors.lastname: Jin
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Chenbiao
authors.initials: C
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Geng
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Zhibo
authors.initials: Z
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Dongxu
authors.initials: D
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics , 457 Zhongshan Road, Dalian 116023, Liaoning, P. R. China.
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang