Electrochemical Deposition of Carbon Prepared on Cu and Ni Cathodes in CaCl₂-LiCl Melts

Abstract

Various carbon materials, including carbon nanotubes and amorphous carbon, were successfully deposited on the nickel and copper cathodes during the electrolysis in the molten CaCl 2 -LiCl at 3.0 V and 600 • C. CaO serving as trapping agent of CO 2 was added before the electrolysis. Electrode reactions were investigated by cyclic voltammetry and chronoamperometry in a three-electrode cell. The results show that the electro-reduction of carbonate ions is dominated by carbon deposition on Ni electrode accompanied with partial evolution of CO, while, on the contrary, the generation of CO is more preferable than carbon deposition on Cu electrode. Electro-reduction of solid carbon were carried out in two-electrode cell and short-time electrolysis were applied to study the formation and growth of the varied carbon microstructure. The formation of carbon nanotubes may be attributed to the evolution of CO. With a SnO 2 anode, O 2 gas was produced during the electrolysis.

Fabrication of graphite via electrochemical conversion of CO2 in a CaCl2 based molten salt at a relatively low temperature

“…Therefore, the shape and size of the cluster is determined by the deposition mass of carbon per unit area. 26 Among PC-1, PC-2 and PC-3, the particle tend to assemble into rod-like structures and the size of the rod-like morphology of PC-3 is a little bigger. In DC-1 sample, the particles seem to grow with each other to form a compact structure.…”

Electrochemical Mechanism of the Carbon Synthesis via Carbonate Ion Electroreduction in Molten Li₂CO₃–K₂CO₃ Mixture

“…Chen et al 23 studied the electrocatalytic graphitization conversion of CO2 using sodium metavanadate homogeneous catalyst in carbonate molten salt. Crucially, given the various morphologies of the obtained carbon products, [7][8][9][10][11][12][13] the microstructure regulation of carbon product needs to be understood from the standpoint of electrodeposition mechanism;…”

“…In recent years, molten salt CO2 capture and electrochemical transformation (MSCC-ET) has attracted a great deal of research attention, as it may afford value-added carbon species obtained from CO2, such as porous carbon, hollow carbon spheres, carbon nanofiber, and carbon nanotube. [7][8][9][10][11][12][13] In the MSCC-ET process, molten salts containing oxides or carbonates are usually employed as the electrolyte, and CO2 is captured from the gaseous phase by oxygen ions present in the melt, leading to the formation of carbonate ions, which are then electrolytically reduced at the cathode to produce neutral carbon species and recyclable oxygen ions. The electrode reactions are described by reactions (1)-(3).…”

“…−2.10, −2.15, and −2.21 V are similar, whereas that of the curve recorded at −1.98 V is slightly different from the other three. According to equation(11), which is derived from integral…”

Sustainable Capture and Conversion of Carbon Dioxide into Valuable Multiwalled Carbon Nanotubes Using Metal Scrap Materials

“…However, only recently has this approach been applied to the synthesis of nanostructured carbons, and limitations reflect lack of understanding of the chemistry and electrochemistry of the combined electrolyte and electrodes. While some groups have observed the effects of electrolyte composition or temperature on the resulting carbon structures, − the strongest influence of carbon-structure control appears to be the cathode structure and composition, − a concept consistent with gas-phase chemical synthesis routes . Early efforts in the growth of carbon based nanostructures from molten carbonates observed growth activity linked to in situ deposition , and/or corrosion of the metal anode.…”