Abstract
We develop a gas-phase controlled synthesis of hybrid nanostructures for biomedical, energy and environmental applications. An evaporation-induced self-assembly (EISA) of heterogeneous aqueous colloid followed by a direct gas-phase electrophoresis for size classification and in situ characterization of mobility size. Transmission electron microscopy, ultraviolet-visible light spectroscopy, and zeta potential measurement are employed orthogonally to provide complementary data and imagery of the hybrid nanostructure. Results show that three types of noble metal – based hybrid nanostructures are successfully synthesized: (1) silver nanoparticles (NPs) decorated on silica nanoparticle (SiO2-NP) and (2) AgNPs decorated in a cluster of SiO2-NPs (SiO2-NPC), and (3) AgNPs decorated in a cluster of TiO2 NPs (TiO2-NPC). Physical sizes, morphology, and compositions of Ag-SiO2 NPs and Ag-TiO2 NP were tunable through the adjustments of precursor concentrations and the selected mobility sizes. The performance in surface plasmon resonance, colloidal stability, and dispersibility of Ag NPs enhanced significantly in an aqueous environment after hybridizing with SiO2-NPC and TiO2-NPC. The photocatalytic activity of Ag-TiO2 NPC was strongly affected by the light irradiation and the ligand-nanoparticle interaction. Under conditions of simultaneous competitive adsorption of MB and BSA, the combination of Ag NPs improved the photocatalytic activity of TiO2-NPC-based catalysts. Results also show that silsesquioxane – crumpled graphene oxide nanoparticle (SQ-GO NP) and copper oxide @ UiO-66 nanocrystal (CuO@UiO-66 NP) were successfully synthesized. The hybridization of silsesquioxane effectively reduced the aggregation of crumpled graphene oxide nanoparticles during thermal treatment. UiO-66 nanocrystal were used as a template to control the physical size and site distribution of CuO NPs in the hybrid nanostructure which increased the number of active sites for catalytic reaction. The synthesized hybrid NPs exhibited high catalytic performance and stability for catalytic CO oxidation reaction. Our work describes a prototype methodology to convert well-dispersed colloidal solution into hybrid nanostructures with a high purity and well-controlled material properties through gas-phase EISA. The work demonstrates here can be applied for the synthesis of other types of hybrid nanostructure colloids (e.g., Ag-ZnO NPC, Ag-graphene NPC) for future biomedical, energy and environmental applications.