Electrolytic production of carbon nano-tubes in chloride-oxide melts under carbon dioxide pressure

Abstract

The electrochemical study of peculiarities of carbon solid phase electrodeposition from halide melts (NaCl:KCl, mole ratio 1:1; NaCl: KCl:CsCl, mole ratio 0.3: 0.245: 0.455), saturated by carbon dioxide under excessive pressure up to 1.5 Mpa was carried our in temperatures range 500/800 °C by the method of cyclic voltammetry. It has been found that the cathodic process occurs in three stages at sweep rates of ≤0.1 Vs-1, and its electrochemical-chemical electrochemical (ECE) mechanism has been suggested. The chemical, phase and structural composition of cathode roducts were determined. It has been found that cathode deposits contain carbon nano-sized particles of different forms and structure: blocks of amorphous carbon, crystalline graphite, carbon nanotubes (CNT) and nanofibres. The majorities of obtained CNT are multi-wall and have a curved form. Most often CNT are collected in balls, rarely -are located as individual tubes. As a rule, tubes of one diameter organize one ball. Outer diameter of tubes is from 5 to 250 nm, and internal diameter is from 2 to 140 nm. Correlation between product structure and yield gainst electrolysis conditions and regimes were established. © 2007 Springer.