Effect of Cation Intercalation on the Growth of Hexagonal WO3 Nanorods

The growth mechanism of hexagonal tungsten oxide (h-WO3) nanorods is investigated using molecular dynamics simulation. The results show that cation intercalation has a great impact on the formation of h-WO3 nanorods, reflected from the attractive interaction between the growth species (polytungstate anion, W10O32 4–) and crystal faces of (001) and (100). In particular, an appropriate amount of intercalated cations not only accelerate the crystal growth but also induce the formation of one-dimensional nanostructure of h-WO3 nanorods along the direction of [001]. An excess of intercalated cations would be unfavorable to the evolution of rod shape. Ammonium ion (NH4 +) is found to be the most stable in a hexagonal tunnel, hence being effective in inducing the 1D morphology of h-WO3. The main findings from the simulations are also verified by experiments.