Fast Fragmentation Of Metal Oxide Nanoparticles Via Reduction In Oxyhydrogen Flame

Fast fragmentation of 20 nm iron oxide and 60 nm tin oxide nanoparticles into a few nanometer nanoparticles in a diffusion oxyhydrogen flame is reported. The phenomenon is explained by the in situ reduction of generated 20-60 nm nanoparticles. The fragmentation occurs due to reduction induced instability in the oxygen-deficient surface. Simulated experiments with electron irradiation and characterization with x-ray absorption spectroscopy substantiated this mechanism. This finding may open a route to continuously generate a few nanometer scale nanoparticles of various oxides in a flame synthesis. (C) 2007 American Institute of Physics.