PM2.5 is an important factor affecting air quality. Coal-fired power plants, oil-fired automobile ships, especially diesel engine automobile ships, are the sources of PM2.5. With the development of China's automobile industry and the increase of automobile ownership, the treatment technology of automobile exhaust has attracted more and more attention.

Environmental protection and sustainable development have become important issues that human beings must consider. Photocatalytic technology, as a branch of green chemistry, is an important environmental protection treatment industry in the future.

Because of its high chromogenic efficiency and low price, nano tungsten trioxide has always been the preferred electrochromic compound. In addition, as a photocatalytic hydrogen production electrode material, nano-tungsten trioxide has also been widely concerned.

Although tungsten carbide has platinum-like catalytic performance and strong anti-CO poisoning ability, its dispersibility is poor, its specific surface area is small, it is easy to agglomerate, and its conductivity is poor, and its catalytic activity is not ideal. Compared with platinum and other noble metal catalysts, there is still a big gap.