Ordered Mesoporous Zeolite Thin Films with Perpendicular Reticular Nanochannels of Wafer Size Area

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 (Im3m) 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).