Tungsten-based oxide electrochromic film is a phenomenon in which the optical properties of materials change reversibly under the action of applied electric field. It can be applied to building intelligent windows, automotive anti-glare rearview mirrors, display devices and other fields. As a stable non-stoichiometric tungsten oxide, W₁₈O₄₉ can synthesize a variety of microstructures by various wet chemical methods, showing excellent performance in electrochromic, sensor and other fields.

With the rapid development of modern industry, a large amount of industrial wastewater, such as untreated or untreated, is directly discharged into the natural world, causing enormous pollution damage to the environment and seriously affecting human health. Photocatalysis refers to the fact that when the visible light is irradiated onto the semiconductor powder in the aqueous solution, the dye molecules are decomposed into CO2, H2O and the like which are harmless to the environment.

Ethyl acetate is a widely-used fine chemical product widely used in cellulose acetate, ethyl cellulose, chlorinated rubber, vinyl resin, cellulose acetate, synthetic rubber,  paints.Traditionally, the esterification catalytic reaction of ethyl acetate is generally  by using an acid as a catalyst. In addition to the conventional inorganic acid, there is also a solid super acid such as a mesoporous material.

Esterification is an important unit reaction in organic synthesis. In traditional methods, liquid acids such as sulfuric acid, phosphoric acid and p-toluene sulfonic acid are often used as catalysts. There are some problems such as difficult separation of catalysts from products, high energy consumption, corrosion equipment and environmental pollution.