Carbon nanotubes for environmental protection

Abstract

Nanotechnology is based on the fact that very small structures usually have new properties and behavior that are not observed in bulk matter of the same composition. Carbon nanotubes are one of the most striking nanometric structures. Their properties depend upon diameter and chirality. Carbon nanotubes have high length to radius ratio, high degree of mechanical strength and flexibility. Carbon nanotubes can behave like metallic, semi-conducting or insulating material. Carbon nanotubes have attracted major attention in latest applications such as nanodevices, field emission, gas adsorption, composite reinforcement, metal composites, and as a catalyst supports because they possess exceptional mechanical properties, unique electrical properties, high chemical and thermal stability and a large specific surface area. The properties of carbon nanotubes can be altered by encapsulating metals to make electrical or magnetic nanocables structures. Carbon nanotubes may therefore be suitable for sorbing hydrogen or separating gases and also can be used as energy storage, membranes for gaseous adsorption and sensors for environmental application. This review discusses the main concepts behind the role of carbon nanotubes for the special application in the field of environmental protection. The major points which are discussed in this review are: Introduction to carbon nanotubes: in this section we discuss the main synthesis routes of nanotubes and their properties Use of carbon nanotubes for energy storage: hydrogen storage is considered to be an ideal for its clean and abundantly reserved. Storage and transportation of hydrogen is an important challenge which has been focused on the use of carbon nanotubes. Use of carbon nanotubes as a sorbents: carbon nanotubes are thought to be very good sorbent for various toxic gases, dioxins, and volatile organic compounds. Use of carbon nanotubes as sensors: carbon nanotubes are thought to be promising candidate for nano scale sensing material for the detection of various pollutants in air like volatile organic compounds such as benzene and toluene.