Tungsten oxide nanoparticles grown by condensation in gas using domestic appliances

Abstract

We report on the preparation of WO3 nanostructures using tungsten wire and iron wool in a domestic microwave oven. Pure WO3 nanoparticles were octahedral or rhombohedral while iron containing nanoparticles were spheroidal. Nanoparticles of monoclinic and cubic WO3 were found in the interior of burned commercial light bulbs, where they grow by a spontaneous reactive gas condensation process. This process was emulated heating a W filament under N2 inside a glass bell jar with a small air leak.