Design, synthesis and characterization of hierarchical porous stacked thin films based on MOFs and ordered mesoporous oxides

ARCIDIACONO, MELINA; ALLEGRETTO, JUAN A; AZZARONI, OMAR; ANGELOMÉ, PAULA C.; RAFTI, MATIAS

Journal of Materials Chemistry A

Royal Society of Chemistry

Año: 2024 vol. 12 p. 5282 - 5293

2050-7488

Sub-micrometre thin alternate bilayers of materials with appropriate refractive index contrast are widely used for the assembly of sensors based on the stimuli-responsiveness of such 1D photonic crystals (PC). A breakthrough in this sensing strategy occurred when porous metal oxides were included in the nanoarchitectures replacing the initially employed dense dielectrics; however, a new degree of complexity was recently enabled by the availability of highly ordered multiporous materials. Specifically, we studied the integration of two kind of materials with different refractive indexes: Si- and Ti-based highly ordered mesoporous oxides and defined pore sizes, and both Zr- and Zn-based Metal Organic Frameworks (UiO-66 and ZIF-8 MOFs), featuring microporosity and chemically tuneable affinity. For this appealing multiporous 1D-PCs option to be feasible, an important issue must be tackled, i.e., the synthesis conditions must guarantee the preservation of structural and chemical integrity when both building blocks are assembled into bilayers. We studied thus the influence of usual synthesis procedures employed for individual materials on the available porosity, crystalline structure, and morphology of bilayers, and propose suitable paths for the integration of multilayers capable of acting as 1D-PCs with both meso- and microporosity and enhanced selectivity.