title: Stable isolated metal atoms as active sites for photocatalytic hydrogen evolution.
abstract: The process of using solar energy to split water to produce hydrogen assisted by an inorganic semiconductor is crucial for solving our energy crisis and environmental problems in the future. However, most semiconductor photocatalysts would not exhibit excellent photocatalytic activity without loading suitable co-catalysts. Generally, the noble metals have been widely applied as co-catalysts, but always agglomerate during the loading process or photocatalytic reaction. Therefore, the utilization efficiency of the noble co-catalysts is still very low on a per metal atom basis if no obvious size effect exists, because heterogeneous catalytic reactions occur on the surface active atoms. Here, for the first time, we have synthesized isolated metal atoms (Pt, Pd, Rh, or Ru) stably by anchoring on TiO2 , a model photocatalystic system, by a facile one-step method. The isolated metal atom based photocatalysts show excellent stability for H2 evolution and can lead to a 6-13-fold increase in photocatalytic activity over the metal clusters loaded on TiO2 by the traditional method. Furthermore, the configurations of isolated atoms as well as the originality of their unusual stability were analyzed by a collaborative work from both experiments and theoretical calculations.
authors.affiliation: Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237 (P.R. China), Fax: (+86) 21-64252127.
authors.forename: Jun
authors.initials: J
authors.lastname: Xing
authors.forename: Jian Fu
authors.initials: JF
authors.lastname: Chen
authors.forename: Yu Hang
authors.initials: YH
authors.lastname: Li
authors.forename: Wen Tao
authors.initials: WT
authors.lastname: Yuan
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.forename: Li Rong
authors.initials: LR
authors.lastname: Zheng
authors.forename: Hai Feng
authors.initials: HF
authors.lastname: Wang
authors.forename: P
authors.initials: P
authors.lastname: Hu
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Hui Jun
authors.initials: HJ
authors.lastname: Zhao
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Hua Gui
authors.initials: HG
authors.lastname: Yang
keywords: noble metals; photocatalysis; single atom; titanium; water splitting