Ordered Mesoporous Zeolite Thin Films with Perpendicular Reticular Nanochannels of Wafer Size Area
Journal
Chemistry of Materials
Journal Volume
30
Journal Issue
22
Pages
8303-8313
Date Issued
2018
Author(s)
Abstract
Highly ordered mesoporous zeolite thin films (MZTFs) are grown at rigid substrates via molecular interaction from ternary structure-directing agents (SDAs) in a Stöber-like condition. The ultrathin films (10–20 nm) were deposited layer-by-layer via self-assembly of β-zeolite seeds and SDAs at 40–50 °C, resulting reticular cellular pores and perpendicular nanochannels with average pore sizes (6.7 ± 1.1 nm). The walls of the nanochannels consist of zeolitic structures in microcrystallines. Compared to cylindrical mesochannels of amorphous silica thin films, the MZTFs with reticular mesochannels demonstrate 5R/6R stretching modes (550–650 cm–1) and significantly enhanced hydrothermal stability. The MZTFs were characterized in top-view and cross-sectional electron microscopies (SEM/HRSEM/HRTEM) as well as X-ray scattering techniques (GIXRD/GISAXS), which confirm a body-centered tetragonal (Im3̅m) unit cell with unique Moiré patterns. Upon calcination, the film thickness is reduced to 10.6 nm with a structure transformation to a hexagonal phase. The hydrothermally stable MZTFs can serve as excellent hard templates for growing dense nanoparticle arrays and confining their diameters to well-defined sizes (4.8 ± 1.3 nm).
Type
journal article