Synthesis of nanometal oxides and nanometals using hot-wire and thermal CVD

We report the synthesis of nano-oxides of molybdenum, tungsten, and zinc. Molybdenum oxide (MoO3) and tungsten oxide (WOx) were produced by hot-wire CVD with molybdenum and tungsten filaments, respectively while zinc oxide (ZnO) was produced by thermal CVD. When high purity molybdenum wire was oxidized at ambient system atmosphere, nanorods and nanostraws of MoO3 with length ranging from ∼ 20–80 nm and diameters ranging from ∼ 5–15 nm were produced. Also, the oxidation of the tungsten filament led to the deposition of tungsten oxide nanorods (10–25 nm diameter and 75–90 nm long) and nanospheres with diameters of ∼ 60 nm. Each oxide was reduced to its metallic form by annealing in a hydrogen environment to produce metallic nanoparticles. Nanorods and nanoribbons of ZnO with diameters ranging from 20–65 nm and lengths up to 2 μm were also produced.