Local Structure of TiO2/2D Mordenite Mesoporous Nanocomposites Probed by NMR

New TiO2/2D mordenite nanocomposites were synthetized from lamellar mordenite by introduction of titanium tetraetoxide (TEOT) into the interlamellar space with further hydrolysis and calcination. Anatase nanoparticles with an average size of 4 nm form pillars separating mordenite layers, creating mesoporosity. The surface area, pore size distribution, and total pore volume of the nanocomposites depend on the media in which the TEOT hydrolysis occurs. Magic angle spinning nuclear magnetic resonance (MAS NMR) on H-1, Na-23, Al-27, and Si-29 nuclei was used to study the local structure of synthetized nanocomposites. It was established that in the studied TiO2/2D mordenite nanocomposites, the removal of organic cations during preparation results in a partial collapse of the local mordenite structure. Si-29 MAS NMR reveals an important contribution from isolated silanol groups (SiO)(3)Si-OH, Q3 sites. The obtained TiO2/2D mordenite nanocomposites could be considered as an effective way of immobilization of the TiO2 photocatalyst, which creates opportunity for their application for water purification under flow conditions with a high mass transfer.

Automated summary

New TiO2/2D mordenite nanocomposites were synthesized by introducing titanium tetraetoxide into the interlamellar space of lamellar mordenite, followed by hydrolysis and calcination. The nanocomposites exhibited mesoporosity and contained anatase nanoparticles as pillars between mordenite layers. The surface area, pore size distribution, and total pore volume of the nanocomposites were influenced by the hydrolysis medium. The removal of organic cations during preparation led to a partial collapse of the local mordenite structure. This study provides insights into the use of TiO2/2D mordenite nanocomposites for water purification.