title: Ag Nanoparticle/Polydopamine-Coated Inverse Opals as Highly Efficient Catalytic Membranes.
abstract: Polymeric three-dimensional inverse-opal (IO) structures provide unique structural properties useful for various applications ranging from optics to separation technologies. Despite vast needs for IO functionalization to impart additional chemical properties, this task has been seriously challenged by the intrinsic limitation of polymeric porous materials that do not allow for the easy penetration of waterborne moieties or precursors. To overcome this restriction, we present a robust and straightforward method of employing a dipping-based surface modification with polydopamine (PDA) inside the IO structures, and demonstrate their application to catalytic membranes via synthetic incorporation of Ag nanoparticles. The PDA coating offers simultaneous advantages of achieving the improved hydrophilicity required for the facilitated infiltration of aqueous precursors and successful creation of nucleation sites for a reduction of growth of the Ag nanoparticles. The resulting Ag nanoparticle-incorporated IO structures are utilized as catalytic membranes for the reduction of 4-nitrophenol to its amino derivatives in the presence of NaBH4. Synergistically combined characteristics of high reactivity of Ag nanoparticles along with a greatly enhanced internal surface area of IO structures enable the implementation of remarkably improved catalytic performance, exhibiting a good conversion efficiency greater than 99% while minimizing loss in the membrane permeability.
authors.forename: Gwan H
authors.initials: GH
authors.lastname: Choi
authors.forename: Do Kyung
authors.initials: do K
authors.lastname: Rhee
authors.forename: A Reum
authors.initials: AR
authors.lastname: Park
authors.forename: Min Jun
authors.initials: MJ
authors.lastname: Oh
authors.forename: Sunghwan
authors.initials: S
authors.lastname: Hong
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science, and Technology and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Richardson
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science, and Technology and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Junling
authors.initials: J
authors.lastname: Guo
authors.affiliation: ARC Centre of Excellence in Convergent Bio-Nano Science, and Technology and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
authors.forename: Pil J
authors.initials: PJ
authors.lastname: Yoo
keywords: catalytic membranes; inverse opal; polydopamine; porous structures; silver nanoparticle