Used as a precursor in the production of tungsten metal, essential for high-strength alloys and light bulb filaments. Employed in gas sensors for detecting reducing gases like hydrogen and carbon monoxide, as well as toxic gases such as nitrogen dioxide. Applied in electrochromic windows and smart coatings that change color or transparency with applied voltage, aiding light and heat control in buildings. Utilized as a yellow to orange pigment in ceramics and paints. Serves as a catalyst in industrial reactions, including photocatalysis for organic pollutant decomposition under sunlight, wastewater and air treatment, and hydrogen production from water using solar energy. Also used in radiation shielding materials due to tungsten's high density.