Activated carbon is a kind of specially treated carbon, in which organic raw materials (fruit shells, coal, wood, etc.) are heated in air-isolated conditions to reduce the non-carbon components (a process known as carbonization), then reacted with gases to erode the surface produce a microporous well-developed structure (a process known as activation). Since the activation process is a microscopic process, i.e. the surface erosion of a large number of molecular carbons is point erosion, resulting in the surface of the activated carbon countless tiny pores. Most of the micropores on the surface of activated carbon have a diameter of between 2 50 nm, even a small amount of activated carbon has a huge surface area of 500 to 1500 m2 per gram of activated carbon, almost all applications of activated carbon are based on this feature of activated carbon.