A novel route to synthesize carbon spheres and carbon nanotubes from carbon dioxide in a molten carbonate electrolyzer

Abstract

Carbon dioxide is readily converted into carbon spheres (CSs) and carbon nanotubes (CNTs) in a molten carbonate electrolyzer.

Electrochemical conversion of CO2 into value-added carbon with desirable structures via molten carbonates electrolysis

“…8b, which proves that the CNTs formed by electrolysis have exceptional uniformity. 43 Raman spectroscopy is utilized to measure and evaluate the graphitization degree of CSs and CNTs, as shown in the Fig. 9a and b, respectively.…”

Mass Production and Growth Mechanism of Carbon Nanotubes in Optimized Mechanothermal Method

“…The main methods for the production of carbon nanotubes are arc discharge [1], laser ablation [2], chemical vapor deposition (CVD) [3], electrolysis [4], and mechanothermal [5]. In the CVD and flame approaches, a high weight percentage of metal impurities is usually produced which required complex purification steps.…”

The effect of CaCO3 in the formation of carbon nanotubes via electrolysis of molten Li2CO3/CaCO3 mixtures

“…The use of mixed electrolytes appears as an alternative to reduce costs. The calcium carbonate (CaCO 3 ) is one of the electrolytes that has been studied to replace Li 2 CO 3 26,31–34 because it is one of the most abundant minerals on the planet and relatively inexpensive. However, studies with mixed Li 2 CO 3 /CaCO 3 electrolytes lack a systematic analysis of the electrolyte and electrolysis conditions in order to identify more clearly the reasons that lead to the formation of CNTs.…”

“…22,23 Studies on the various parameters of the synthesis by electrolysis in molten carbonates (electrode materials, electrolyte, temperature, and electric current) allowed the control of the morphologies and structures obtained. [24][25][26][27][28] The growth of carbon nanostructures from electrochemical techniques remains a new idea and it has been shown to be economically advantageous compared to conventional synthesis processes (chemical vapor deposition, electric arc discharge, and polymer stretching/carbonization) as it reduces the production cost by about 100 times. 2,16 Most studies are focused on the use of lithium carbonate (Li 2 CO 3 ) as an electrolyte.…”