Tungsten trioxide (WO3) is an n-type semiconductor oxide that possesses a large bandgap in the range of 2.6–3.0 eV and has the potential for a variety of applications such as electrochemical devices, photovoltaic devices, photocatalytic devices, electrochromic devices, dye-sensitized solar cells, optical devices, field-emission displays, and gas sensors. Meanwhile, with the development of one-dimensional nanostructures, dimensionality and size of the materials have also been regarded as critical factors that may bring some novel and unexpected properties.

Semiconductor metal oxides (SMOs) are highly potent gas sensors for gaseous detection in terms of screening of air eminence, low expenditure on synthesis and sensing property that can be modified. The semiconductor metal oxide gas sensor is considered the most capable gas-sensing device due to its high sensitivity, fast response, low cost, and small size.

Tungsten trioxide (WO3) has been extensively studied due to its affinity for visible light, chemical inertness, thermal stability, and harmlessness. These excellent properties make this material useful for solar-related applications such as photocatalysts, solar cells, water splitting, and hydrogen generation.