Electrochemical formation of carbon nano-powders with various porosities in molten alkali carbonates

Overview on CO2 Valorization: Challenge of Molten Carbonates

“…Nevertheless, processing this molecule into valuable fuels by electrolysis is a more recent challenge. The literature pointing out the feasibility and interest of electroreduction of CO2 in molten carbonates into elemental C or CO is recent and significant, but is lacking a systematic approach and rigorous data (Groult et al, 2003(Groult et al, , 2006Kaplan et al, 2002Kaplan et al, , 2010Le Van et al 2009;Yin et al, 2013;Chery et al, 2014Chery et al, , 2015Ijije et al, 2014). Kaplan et al and Groult et al were the first in conceiving the conversion of CO2 in molten carbonates into energy-storage materials (Groult et al, 2003;Kaplan et al, 2002).…”

Direct Conversion of Greenhouse Gas CO2 into Graphene via Molten Salts Electrolysis

“…[16] More recently,i onic liquids were investigated for electrochemical reduction of CO 2 at room temperature owing to their wide electrochemical window and high solubility of CO 2 ; [17] however,t he high cost of ionic liquids remains an impediment to their widespread adoption.M olten carbonates are low-cost electrolytes with high ionic conductivity and low vapor pressure, [18 ] and they were investigated extensively as alternatives for electrochemical reduction of CO 2 . [18][19][20][21][22][23][24][25][26] However,t he resultingp roducts were almostexclusivelyamorphous carbon. [25] Therefore, to produce graphene by electrochemical reduction of CO 2 remains ac onsiderable challenge, which requires good control of kinetics, such as diffusivities of multiple ions, solubility of various gases, nucleation and growth of carbon on surface, as well as ac omprehensive understandingo ft he thermodynamicso fr eactions.…”

Optimized Electrolytic Carbon and Electrolyte Systems for Electrochemical Capacitors

“…One potential method of achieving this is the synthesis of carbons through the electrolytic reduction of molten carbonate salts. [4,5,9,[23][24][25][26] This method of carbon synthesis has received considerable interest in recent years, both by this group [26][27][28] and a range of further…”

“…This has led to the development of a reasonable understanding of the molten carbonate system, particularly with respect to the influence of electrodeposition conditions on the physical and morphological characteristics of carbonatederived carbons. The influence of deposition temperature, [23][24][25][29][30][31] substrate, [23,29,30,[32][33][34][35] electrolyte, [29,30,36] current density, [30,37] and potential [4,24,25,32,33,31,35,38] have all been investigated, with a rich and varied library of carbon microstructures being produced, and with links being drawn between the structure of these carbons and the conditions of electrodeposition. In more recent years this understanding of the molten carbonate system has paved the way for an increased understanding of both the mechanism of carbon formation from molten carbonate salts, [39][40][41] and for the application of molten carbonate reduction in attempts to produce carbons with specific properties or morphologies.…”

“…[27,28] This has indicated that electrochemical performance in aqueous systems is at its highest for materials showing elevated amorphous character, which contributes to increased double layer formation, [28] and high oxygen functionalization, which leads to high pseudo-capacitance. [28] These carbons may be produced through the electroreduction of molten carbonates at low temperatures [23][24][25]28,[29][30][31] or at low current densities relative to the geometric surface area of the working electrode. [28,30,37] Based on these previous results, the work presented here investigates an optimized carbonate-derived carbon and electrolyte system for aqueous electrochemical capacitors.…”