Semiconductor gas sensors are widely used in industry, medicine and environmental monitoring. One of the most important tasks in sensor technology is to reduce the operating temperature of the device, which is possible due to the  optimization of nanostructures, surface modification with catalysts, the manufacture of hybrid or composite nanostructures and the use of ultraviolet or visible light. The purpose of this work is to develop a method for the hydrothermal  synthesis of WO_x/WS₂ composite nanostructures to create sensor layers operating at room temperature, as well as to study the effect of UV irradiation on the gas-sensitive characteristics of the developed layers.