The process of molten salt CO₂ capture and electrochemical conversion provides us with a new way to close the present carbon cycle and mitigate global climate change by transforming the greenhouse gas CO₂ into carbonaceous fuels or chemicals. In this paper, carbon spheres and carbon nanotubes that can be used as a societal resource to serve mankind are synthesized from CO₂ in diverse electrolyte composites with inexpensive metallic electrodes. Carbon products, subsequent to electrolysis, are characterized by EDS, SEM, TEM, Raman, TGA, FTIR, BET and XRD to reveal the elemental composition and morphological and structural features. The results demonstrate that Li–Ca–Na and Li–Ca–K carbonate electrolytes favor carbon sphere formation rather than carbon nanotube formation, and in particular, K₂CO₃ shows enhanced interference with carbon nanotube growth. In contrast, Li–Ca–Ba and Li–Ba carbonate composites present an increase in the carbon nanotube fraction. Additionally, CNTs generated from Li–K, Li–Ba and Li–Ca–Ba present a different diameter. In this way, the CO₂-derived carbon products of carbon spheres and carbon nanotubes could be alternatively synthesized through the appropriate regulation of the electrolyte composition.

中文翻译：

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在熔融碳酸盐电解槽中由二氧化碳合成碳球和碳纳米管的新途径

熔融盐CO _2的捕获和电化学转化过程为我们提供了一种新方法，可以通过将温室气体CO ₂转化为含碳燃料或化学物质来关闭当前的碳循环并缓解全球气候变化。本文利用CO ₂合成了可作为人类社会资源的碳球和碳纳米管。具有廉价金属电极的各种电解质复合材料中的应用。电解后的碳产物通过EDS，SEM，TEM，拉曼，TGA，FTIR，BET和XRD进行表征，以揭示元素组成以及形态和结构特征。结果表明，Li–Ca–Na和Li–Ca–K碳酸盐电解质促进碳球的形成，而不是碳纳米管的形成，特别是K ₂ CO ₃对碳纳米管生长的干扰增强。相反，Li-Ca-Ba和Li-Ba碳酸盐复合材料的碳纳米管分数增加。此外，由Li–K，Li–Ba和Li–Ca–Ba生成的CNT具有不同的直径。这样一来，CO ₂碳球和碳纳米管的碳衍生产物可以通过适当调节电解质成分来合成。