Nitrogen oxide pollution is becoming more and more serious. Coal-fired power plants are the largest source of air pollution in China. The state stipulates that the pollutant flue gas needs denitrification to meet the emission standards. SCR is the mainstream denitrification technology at home and abroad, accounting for more than 90% of the flue gas market, and is the most mature technology of flue gas denitrification.

Tungsten disulfide (WS₂) is considered to be a promising anode material for lithium ion batteries. It is not only cheap and safe, but also has a unique two-dimensional layered structure. The weak van der Waals force links the layers, which is conducive to the rapid diffusion of lithium ions in active materials.

Nitrogen oxides (NO, mainly NO and NO₂) are important atmospheric pollutants, which can directly harm human health, especially the respiratory system, and can cause acid rain, photochemical smog and haze and other important environmental problems. NH₃ selective catalytic reduction is a technology widely used in fixed source flue gas denitrification represented by coal-fired power plants and mobile source NOx emission control represented by diesel vehicles.

Tungsten trioxide, as a catalytic material for hydrogen production from water decomposition, has the advantages of photoelectric double response effect, stability, low light-on voltage, high hydrogen production efficiency, and is also a good electrochromic material.