title: Mesoscopic constructs of ordered and oriented metal-organic frameworks on plasmonic silver nanocrystals.
abstract: We enclose octahedral silver nanocrystals (Ag NCs) in metal-organic frameworks (MOFs) to make mesoscopic constructs O(h)-nano-Ag⊂MOF in which the interface between the Ag and the MOF is pristine and the MOF is ordered (crystalline) and oriented on the Ag NCs. This is achieved by atomic layer deposition of aluminum oxide on Ag NCs and addition of a tetra-topic porphyrin-based linker, 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrabenzoic acid (H4TCPP), to react with alumina and make MOF [Al2(OH)2TCPP] enclosures around Ag NCs. Alumina thickness is precisely controlled from 0.1 to 3 nm, thus allowing control of the MOF thickness from 10 to 50 nm. Electron microscopy and grazing angle X-ray diffraction confirm the order and orientation of the MOF by virtue of the porphyrin units being perpendicular to the planes of the Ag. We use surface-enhanced Raman spectroscopy to directly track the metalation process on the porphyrin and map the distribution of the metalated and unmetalated linkers on a single-nanoparticle level.
authors.affiliation: Department of Chemistry, University of California-Berkeley , Materials Sciences Division, Lawrence Berkeley National Laboratory, and Kavli Energy NanoSciences Institute, Berkeley, California 94720, United States.
authors.forename: Yingbo
authors.initials: Y
authors.lastname: Zhao
authors.forename: Nikolay
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authors.lastname: Kornienko
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.forename: Chenhui
authors.initials: C
authors.lastname: Zhu
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Asahina
authors.forename: Tsung-Rong
authors.initials: TR
authors.lastname: Kuo
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.forename: Chenlu
authors.initials: C
authors.lastname: Xie
authors.forename: Alexander
authors.initials: A
authors.lastname: Hexemer
authors.forename: Osamu
authors.initials: O
authors.lastname: Terasaki
authors.forename: Peidong
authors.initials: P
authors.lastname: Yang
authors.forename: Omar M
authors.initials: OM
authors.lastname: Yaghi