title: Hollow Mesoporous Plasmonic Nanoshells for Enhanced Solar Vapor Generation.
abstract: In the past decade, nanomaterials have made their way into a variety of technologies in solar energy, enhancing the performance by taking advantage of the phenomena inherent to the nanoscale. Recent examples exploit plasmonic core/shell nanoparticles to achieve efficient direct steam generation, showing great promise of such nanoparticles as a useful material for solar applications. In this paper, we demonstrate a novel technique for fabricating bimetallic hollow mesoporous plasmonic nanoshells that yield a higher solar vapor generation rate compared with their solid-core counterparts. On the basis of a combination of nanomasking and incomplete galvanic replacement, the hollow plasmonic nanoshells can be fabricated with tunable absorption and minimized scattering. When exposed to sun light, each hollow nanoshell generates vapor bubbles simultaneously from the interior and exterior. The vapor nucleating from the interior expands and diffuses through the pores and combines with the bubbles formed on the outer wall. The lack of a solid core significantly accelerates the initial vapor nucleation and the overall steam generation dynamics. More importantly, because the density of the hollow porous nanoshells is essentially equal to the surrounding host medium these particles are much less prone to sedimentation, a problem that greatly limits the performance and implementation of standard nanoparticle dispersions.
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Marcin S
authors.initials: MS
authors.lastname: Zielinski
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Choi
authors.affiliation: Interdisciplinary Center for Electron Microscopy (CIME), School of Basic Sciences (SB), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: La Grange
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Miguel
authors.initials: M
authors.lastname: Modestino
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Seyyed Mohammad Hosseini
authors.initials: SM
authors.lastname: Hashemi
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Ye
authors.initials: Y
authors.lastname: Pu
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Birkhold
authors.affiliation: Institute of Bioengineering (IBI) and Institute of Chemical Sciences and Engineering (ISIC), School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.|Institute for Molecular Engineering, University of Chicago , Chicago, Illinois 60637 United States.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Hubbell
authors.affiliation: Laboratory of Optics (LO), School of Engineering (STI), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Demetri
authors.initials: D
authors.lastname: Psaltis
keywords: Composite nanoshell; mesoporosity; plasmonics; solar-vapor; steam nanobubble; thermal cavity