Helical carbon nanotubes currently cost ~15,000–19,000 USD/kg commercially and are ~10–15 times the price of straight carbon nanotubes of similar dimensions. They have not previously been made from the greenhouse gas CO₂ nor had new variants of the helical morphology been demonstrated. In this study, a novel, inexpensive electrosynthesis of these helical nanocarbon materials from CO₂ is presented. This material may be produced by molten carbon growth conditions that (1) maximize torsional stresses, such as those that may occur during rapid, nucleated carbon reduction, (2) enhance defects that cause formation of heptagonal, rather than the conventional hexagonal building blocks of graphene cylindrical walls, and (3) uniformly control those enhanced defects to repeatedly induce a uniform spiral conformation. These conditions are achieved with at least two of the following experimental conditions: (i) high electrolysis current density, (ii) sp³ defect-inducing agents, such as added oxide, and (iii) controlled concentration of iron added to the electrolyte or cathode. Here, it is shown with SEM, TEM, EDX, XRF, and Raman spectroscopy that a molten controlled electrolyte carbonate synthesis to induce defect formation, and a high rate of electrolysis (0.6 A/cm²) leads to a high yield of helical nanotubes, helical nanofibers, or helical nanoplatelet carbon morphologies.

螺旋碳纳米管目前的商业成本约为 15,000-19,000 美元/公斤，是类似尺寸的直碳纳米管价格的 10-15 倍。它们以前不是由温室气体 CO ₂制成的， 也没有证明螺旋形态的新变体。在这项研究中，从 CO ₂电合成这些螺旋纳米碳材料的新型、廉价被表达。这种材料可以通过熔融碳生长条件生产，其 (1) 最大限度地提高扭转应力，例如在快速成核碳还原过程中可能发生的那些，(2) 增强导致形成七边形而不是传统六边形构件的缺陷石墨烯圆柱壁，以及（3）均匀控制那些增强的缺陷以重复诱导均匀的螺旋构象。这些条件通过以下实验条件中的至少两个实现：(i) 高电解电流密度，(ii) sp ³缺陷诱导剂，例如添加的氧化物，以及 (iii) 控制添加到电解质或阴极中的铁浓度。在这里，SEM、TEM、EDX、XRF 和拉曼光谱表明，熔融控制的电解质碳酸盐合成诱导缺陷形成，并且高电解速率 (0.6 A/cm ² ) 导致螺旋纳米管的高产率、螺旋纳米纤维或螺旋纳米片碳形态。