Advantages and disadvantages of electric arc methods for the synthesis of carbon nanostructures

A review of more than 100 contemporary literary works of domestic and foreign researchers on the issues of electric arc synthesis (EAS) of various carbon nanostructures (CNS) has been performed. EAS CNScan be performed in both gaseous and liquid media. EAS in a gaseous medium has a number of advantages, such as high productivity and velocity of the condensation process, as well as ease of control.But this method of synthesis also has disadvantages: it requires a complex vacuum and cooling system, which makes the installation very cumbersome.In addition, this method does not solve the problem of agglomeration of synthesized CNS and has a by-product of synthesis in the form of growth (deposit) on the electrode. EAS in a liquid medium is more compact equipment, as it does not require systems of vacuum (the process takes place at atmospheric pressure) and cooling (liquid medium plays the role of heat dissipation).This method of synthesis uses different types of dielectric liquids – from distilled water (H2O), liquid nitrogen (N2) to hydrocarbon solvents, which can serve as a source of carbon in the synthesis zone.By changing the composition of the liquid phase, it is possible to achieve the synthesis of different types of CNS.Also, this method involves the use of metal electrodes, which, in addition to long service life, can act as catalysts.The metal particles can be encapsulated ANS, forming composites with different magnetic properties.In some studies, it has been shown that mixtures of metal carbides can be formed when metal electrodes are used in the EAS process in a liquid medium.The liquid medium after EASCNS is also of scientific interest. Probably, the liquid medium contains new modifications of soluble organic compounds, which are being researched by researchers around the world.Thus, scientists have found that after EAS in a liquid medium using graphite electrodes, the working solution (C6H6) changed its color.This indicates the formation of soluble organic compounds in it. In the literature review on the basis of literature data the table of modes for industrial synthesis of single-walled CNS is created.Also, a list of modes for the creation of defective CNS as a method of increasing the area of adsorption in nanoparticles. The solution of important problems of the EAS method is recorded: agglomeration of CNS; the problem of forming a deposit; increase productivity.