Electrolytic generation of nano-scale carbon phases with framework structures in molten salts on metal cathodes

An electrochemical Study of mechanisms of electrodeposition of carbon solid phases from halide melts (Na, K vertical bar Cl; Na, K, Cs vertical bar Cl) saturated with carbon dioxide under an excessive pressure of up to 1.5 MPa. has been carried out in the temperature range 550-850 degrees C by cyclic voltammetry. It has been found that the cathode process Occurs in three steps at sweep rates of less than 0.1 V s(-1), and its electrochemical-chemical-electrochemical (ECE) mechanism is suggested. It has furthermore been found that cathodic deposits contain nano-sized carbon particles of different forms and structure: blocks of amorphous carbon, crystalline graphite, carbon nanotubes (CNT), and nanofibres. The outer diameter of the tubes is 5-250 nm, and the internal diameter is 2-140 nm. A correlation between the product structure and yield against electrolysis conditions and regimes has been established.