Recent advances and perspectives in carbon nanotube production from the electrochemical conversion of carbon dioxide

Molten salt-based electrolysis of CO2 to a valuable carbon product is a promising method to overcome the excessive concentration of CO2 in the atmosphere. Carbon nanotubes (CNTs) are one of the most favorable carbon nanomaterials. Recently, scientists have developed a CNT production method using molten salt-based CO2 electrolysis and optimized reaction conditions to obtain desirable CNT products. However, to date, the production of single-walled CNTs (SWCNTs), as a type of CNTs with excellent chemical and physical properties, has not been realized. Here, we review the fundamental principles and process mechanisms of molten salt-based CO2 electrolysis. In addition, we cover the key components for improving CNT production performance, such as cathode, anode, and electrolyte. Furthermore, we investigate the key strategies applied in chemical vapor deposition to produce commercial SWCNTs and suggest a perspective for SWCNT production from CO2 based on material strategies. This paper provides deep insights into the CNT synthesis mechanism as well as a value-addition strategy through cost-efficient and environment-friendly CO2 conversion processes.