LAUSR

Abstract The metastable state hexagonal-tungsten oxide (h-WO3) has been attracting attention over the past decade because of its high reactivity that arises from the hexagonal channels in its crystal structure. Simplification of the process used to synthesize h-WO3 is an important step to facilitate the industrial applications of this material. In this study, we addressed this challenge by developing a spray pyrolysis process to synthesize highly crystalline h-WO3. The ratio of the monoclinic to the hexagonal phase was controlled by adjusting the segregation time. Single-phase h-WO3 nanorods were synthesized using a carrier gas flow rate of 1 L/min, which was equivalent to a segregation time of 18.4 s. The ability of the h-WO3 nanorods to adsorb nitrogen and carbon dioxide was evaluated to confirm the presence of hexagonal channels in the crystal structure.