Novel Aerosol-Based Approach toward Mesoporous Silica Nanoparticles

This study introduces a novel gas-phase method for the synthesis of mesoporous silica nanoparticles (MSNs). The method is a two-step templating approach by first forming silicon-coated carbon structures in a hybrid microwave-plasma/hot-wall reactor followed by an annealing step to produce mesoporous silica with distinct nanostructure and porosity. Two different (sacrificial) carbonaceous templates have been prepared (plasma reactor) and coated (hot-wall reactor), 2D few-layer graphene (FLG) flakes and soot-like fractal aggregates. Results show that the wall thickness of the porous silica structures can be adjusted by changing the concentration of the silicon precursor (monosilane). High monosilane concentrations, however, result in solid silica particles after annealing. Using soot-like particle templates permitted to control of the shell thickness of the hollow porous particles, while the FLG template results in ultrathin silica sheets after heat treatment. The pore volume and specific surface area increase up to 263 m2 g-1 and 0.6 cm3 g-1, respectively, by the formation of hollow porous particles. An adsorption study on carbamazepine reveals up to & AP;86% removal. The gas-phase aerosol-based template method presented here offers scalability and versatility, and it is capable of producing MSNs with a controlled structure and porosity by modifying the carbonaceous templates. An aerosol-based approach for the synthesis of mesoporous silica via a two-step templating procedure is presented. The procedure is tested on soot-like particles and few-layer graphene as sacrificial carbon templates. Coating and annealing them result in different silica nanomorphologies, including hollow particles or 2D silica sheets. Materials show promising results for the adsorption of carbamazepine.image & COPY; 2023 WILEY-VCH GmbH