Rapid, conformal gas-phase formation of silica (SiO2) nanotubes from water condensates

• DOI: 10.1039/c3nr00906h
• Publication Date: 2013-04-23T11:33:52Z
• Authors: Changdeuck Bae; Hyunchul Kim; Yunjeong Yang; Hyunjun Yoo; Josep M. Montero ...; Julien Bachmann; Kornelius Nielsch; Hyunjung Shin
• Keywords: Nanoporous; Nanopore; Nanometre

An innovative atomic layer deposition (ALD) concept, with which nanostructures of water condensates high aspect ratio at equilibrium in cylindrical nanopores can be transformed uniformly into silica (SiO2) near room temperature and ambient pressure, has been demonstrated for the first time. As a challenging model system, we prove conversion porous alumina membranes to nanotubes (NTs) by introducing SiCl4 as metal reactant without involving any catalytic reaction. Surprisingly, NTs reproducibly NTs, where wall thickness deposited per cycle was found limited amount condensed water, it on orders ten nanometers (i.e., over 50 times faster than that conventional ALD). More remarkably, reactions only took place 10–20 minutes or less vacuum-related equipment. The initially adsorbed layers indirectly estimated from formed SiO2 layers. With systematic experimental designs, tackle classical Kelvin equation nanosized pores, role van der Waals forces nanoscale wetting phenomena, is long-standing issue lacking insight. Moreover, show present strategy likely generalized other oxide systems such TiO2. Our approach opens up new avenue ultra-simple preparation oxides allows formation dielectric toward organic electronic photovoltaic applications.