▎ 摘　　要

NOVELTY - Synthesizing helical carbon nanostructures (HCNS) involves: (a) aligning an anode spaced from a cathode for defining an inter-electrode space; (b) introducing a molten carbonate electrolyte into the inter-electrode space; (c) introducing a carbon input into the inter-electrode space; (d) applying a current across the electrodes; and (e) collecting a product that comprises the HCNS from the electrode. USE - The method is useful for synthesizing HCNS (claimed). ADVANTAGE - Conveniently, carbon nanomaterials produced from a molten carbonate by electrolysis can be produced with a relatively low carbon footprint and even a negative carbon footprint, because carbon dioxide (CO2) is consumed as a reactant, and at relatively low cost, as compared to carbon nanomaterials produced by other conventional techniques such as chemical vapor deposition (CVD) synthesis, flame synthesis, or plasma synthesis. The predominance of HCNSs may be produced by molten carbon electrolytic splitting under growth conditions that: (1) maximize torsional stress, such as those that may occur during rapid, nucleated growth; (2) enhance defects that cause formation of heptagonal, rather than the conventional pentagonal building blocks of graphene cylindrical walls; (3) uniformly control those enhanced defects to repeatedly induce a uniform spiral conformation; and (4) employ combinations of (1), (2) and (3). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) HCNS synthesized by a molten carbonate electrolysis method; and (2) a system for making HCNS, comprising: (a) an anode; (b) a cathode; (c) an inter-electrode space that is defined between the anode and the cathode; (d) a source of current for applying a current density is greater than or equal to 0.2 A/cm2 across the electrodes; (e) a source of heat for regulating the inter-electrode space at greater than or equal to 725 degrees C; and (f) a source of carbon for introducing a carbon input into the inter-electrode space.