title: Probing the Interfacial Interaction in Layered-Carbon-Stabilized Iron Oxide Nanostructures: A Soft X-ray Spectroscopic Study.
abstract: We have stabilized the iron oxide nanoparticles (NPs) of various sizes on layered carbon materials (Fe-oxide/C) that show excellent catalytic performance. From the characterization of X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), scanning transmission X-ray microscopy (STXM) and X-ray magnetic circular dichroism spectroscopy (XMCD), a strong interfacial interaction in the Fe-oxide/C hybrids has been observed between the small iron oxide NPs and layered carbon in contrast to the weak interaction in the large iron oxide NPs. The interfacial interaction between the NPs and layered carbon is found to link with the improved catalytic performance. In addition, the Fe L-edge XMCD spectra show that the large iron oxide NPs are mainly γ-Fe2O3 with a strong ferromagnetic property, whereas the small iron oxide NPs with strong interfacial interaction are mainly α-Fe2O3 or amorphous Fe2O3 with a nonmagnetic property. The results strongly suggest that the interfacial interaction plays a key role for the catalytic performance, and the experimental findings may provide guidance toward rational design of high-performance catalysts.
authors.affiliation: ‡Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Jinyin
authors.initials: J
authors.lastname: Liu
authors.forename: Guanqi
authors.initials: G
authors.lastname: Zhao
authors.affiliation: §Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Gao
authors.affiliation: ‡Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Tolek
authors.initials: T
authors.lastname: Tyliszczak
authors.affiliation: ‡Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Per-Anders
authors.initials: PA
authors.lastname: Glans
authors.affiliation: ‡Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Guo
authors.affiliation: §Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
authors.forename: Ding
authors.initials: D
authors.lastname: Ma
authors.forename: Xu-Hui
authors.initials: XH
authors.lastname: Sun
authors.forename: Jun
authors.initials: J
authors.lastname: Zhong
mesh_terms: D002244:Carbon / Q000737:chemistry*; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008422:Materials Testing; D056951:Photoelectron Spectroscopy
chemical_list: D058185:Magnetite Nanoparticles; D002244:Carbon
keywords: catalysts; interfacial interaction; iron oxide; layered carbon; magnetic property; soft X-ray spectroscopy