The production of carbon nanotubes from carbon dioxide challenges and opportunities

Recent advances in the production of carbon nanotubes (CNTs) are reviewed with an emphasis on the use of carbon dioxide (CO2) as a sole source of carbon Compared to the most widely used carbon precursors such as graphite methane, acetylene ethanol, ethylene and coal derived hydrocarbons, CO2 is competitively cheaper with relatively high carbon yield content However, CNT synthesis from CO2 is a newly emerging technology and hence it needs to be explored further A theoretical and analytical comparison of the currently existing CNT CO2 synthesis techniques is given including a review of some of the process parameters (i e temperature pressure catalyst etc) that affect the CO2 reduction rate Such analysis indicates that there is still a fundamental need to further explore the following aspects so as to realize the full potential of CO2 based CNT technology (1) the CNT CO2 synthesis and formation mechanism (2) catalytic effects of transitional metals and mechanisms (3) utilization of metallocenes in the CNT-CO2 reactions, (4) applicability of ferrite-organometallic compounds in the CNT CO2 synthesis reactions and (5) the effects of process parameters such as temperature etc