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.