Synthesis of WO3 Nanorods by Thermal CVD at Various Gas Flow Rates and Substrate Temperatures

Tungsten oxide (WO 3 ) nanomaterials have been extensively researched for applications such as semiconductor gas sensors and photocatalysis. We have synthesized WO 3 nanorods (diameters: 100–150 nm; lengths: 400–500 nm) with high yields by thermal chemical vapor deposition (CVD). In our unique two-step heating process, catalysts were not required in the temperature zone (500–600°C) of substrate. It suggests the experimental conditions played a dominant role in the growth of WO 3 nanorods, especially in the case of the O 2 flow rate and substrate temperature. Moreover, this relatively simple growth process can lead to effective large-scale production of WO 3 nanorods.