The friction and wear property of tungsten disulfide nano powder is a new topic, as a new type of solid lubricating material, tungsten disulfide has excellent lubricating property, it has a layered hexagonal structure, the W and S elements in the layer are combined by covalent bond, and the molecular bond formed by S-S in the layer is combined. Because of the low bond energy of the latter, it is easy to slip during the friction process, so it has lower friction coefficient.

Tungsten oxide is the potential oxide material in the energy field for its rich content in the earth, highly adjustable composition, high chemical stability at low pH value and excellent conductivity. Now it has wide application in seven fields including electrochromic and photochromic, lithium-ion battery anode materials and heat insulation materials, etc.

Currently tungsten oxide has been widely used in electrochromic intelligent glass, optical device, supercapacitor, gas sensor, photocatalysis, photothermal therapy and other application fields. With the rapid development of nano science and technology, more and more synthesis methods of nano tungsten oxide are available, mainly has there kinds of methods including vapor deposition, liquid-phase synthesis and solid-phase synthesis.

With the rapid development of industry, the overuse of oil, natural gas and other resources has caused serious pollution of air and environment. The manufacture of gas sensing material for detecting toxic and harmful gases has became a hot research spot. Nano tungsten trioxide used as gas sensing material can be divided into four structures。