Photoelectrochemical and photocatalytic properties of tungsten oxide nanorods grown by thermal evaporation

Tungsten oxide (WO3) nanorods were grown on W substrates by thermal evaporation of WO3 powder at high temperature without using any catalyst and then by subsequent air annealing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations revealed that the synthesized WO3 nanorods were highly dense and single crystalline. Optical absorption measurements showed that WO3 nanorods can absorb light up to 480–500 nm. WO3 nanorods showed good photocurrent response with maximum current density of 1.5 mA cm−2. The photocatalytic degradation of methylene blue revealed that WO3 nanorods have enhanced photocatalytic efficiency.