(705e) Two-Step Gas Phase Synthesis of Janus-Like and Core-Shell FexOy-TiO2 Composite Nanoparticles

Composite nanoparticles are of a great interest because the properties of several different materials can be combined. In this study, Fe_xO_y-TiO₂ nanoparticles were synthesized in two steps. Iron oxide and titanium dioxide were chosen because they are known to have magnetic and photocatalytic properties, respectively. Fe_xO_y nanoparticles were synthesized using the Liquid Flame Spray technique by feeding a solution of ferrocene dissolved in xylene into a high-temperature H₂-O₂ flame. The flame-made nanoparticles were collected with an electrostatic precipitator and mixed with titanium(IV) isopropoxide (TTIP) liquid. The mixture was sprayed into a tube furnace where TTIP was thermally decomposed to form TiO₂. Both Fe_xO_y and Fe_xO_y-TiO₂ nanopowders were characterized with TEM and XRD. The TEM images show that by altering the process parameters, the structure of the composite nanoparticles can be tailored between Janus-like and core-shell particles consisting of an agglomerated Fe_xO_y particle attached to or inside a spherical TiO₂ particle, respectively. Mixing nanopowder into precursor liquid that is thermally decomposable is a versatile and easy method to synthesize composite nanopowders which are formed of particles containing two or more different materials and properties, as demonstrated in this study.