Carbon nanotube-based environmental technologies: the adopted properties,primary mechanisms,and challenges

Carbon nanotubes (CNTs) show great potential and bright prospect in the field of environment. It is believed that this new kind of material will bring opportunities and benefits to the environmental protection and pollution control. In recent years, a lot of CNT-based environmental technologies have been developed and applied with successful results, but the adequate understanding and large-scale industrial applications of these technologies are lacking. This paper systematically reviews current environmental applications of CNTs, including pollution treatment and environmental remediation, environmental sample analysis, environmental monitoring and sensing, and design of environment-friendly products. The adopted properties of CNTs are introduced. The main roles of CNTs in these technologies are illustrated. Additionally, the main current challenges to realizing their practical applications are analyzed and discussed, involving toxicity and ecological risks, production costs, general applicability, long-term effect, and public acceptance. Further studies should give priority to the toxicity and environmental risk of CNTs when developing new CNT-based technologies. Research on standardizing toxicity testing and risk assessment of CNTs is highly recommended and a large number of toxicity data of CNTs are needed.