title: Tunable oxygen activation for catalytic organic oxidation: Schottky junction versus plasmonic effects.
abstract: The charge state of the Pd surface is a critical parameter in terms of the ability of Pd nanocrystals to activate O2 to generate a species that behaves like singlet O2 both chemically and physically. Motivated by this finding, we designed a metal-semiconductor hybrid system in which Pd nanocrystals enclosed by {100} facets are deposited on TiO2 supports. Driven by the Schottky junction, the TiO2 supports can provide electrons for metal catalysts under illumination by appropriate light. Further examination by ultrafast spectroscopy revealed that the plasmonics of Pd may force a large number of electrons to undergo reverse migration from Pd to the conduction band of TiO2 under strong illumination, thus lowering the electron density of the Pd surface as a side effect. We were therefore able to rationally tailor the charge state of the metal surface and thus modulate the function of Pd nanocrystals in O2 activation and organic oxidation reactions by simply altering the intensity of light shed on Pd-TiO2 hybrid structures.
authors: Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, School of Chemistry and Materials Science, CAS Key Laboratory of Materials for Energy Conversion and Laboratory of Engineering and Material Science, University of Science and Technology of China, Hefei, Anhui 230026 (P.R. China) http://staff.ustc.edu.cn/∼yjxiong/
authors: Ran
authors: R
authors: Long
authors: Keke
authors: K
authors: Mao
authors: Ming
authors: M
authors: Gong
authors: Shan
authors: S
authors: Zhou
authors: Jiahua
authors: J
authors: Hu
authors: Min
authors: M
authors: Zhi
authors: Yang
authors: Y
authors: You
authors: Song
authors: S
authors: Bai
authors: Jun
authors: J
authors: Jiang
authors: Qun
authors: Q
authors: Zhang
authors: Xiaojun
authors: X
authors: Wu
authors: Yujie
authors: Y
authors: Xiong
keywords: heterogeneous catalysis; oxygen activation; palladium; plasmonics; titania