Tracking airborne CO(2) mitigation and low cost transformation into valuable carbon nanotubes

Primary evidence of the direct uptake of atmospheric CO(2) and direct transformation into carbon nanotubes, CNTs, is demonstrated through isotopic labeling, and provides a new high yield route to mitigate this greenhouse gas. CO(2) is converted directly to CNTs and does not require pre-concentration of the airbone CO(2). This C2CNT (CO(2) to carbon nanotube) synthesis transforms CO(2-gas) dissolved in a 750 °C molten Li(2)CO(3), by electrolysis, into O(2-gas) at a nickel electrode, and at a steel cathode into CNTs or carbon or nanofibers, CNFs. CNTs are synthesized at a 100-fold price reduction compared to conventional chemical vapour deposition, CVD, synthesis. The low cost conversion to a stable, value-added commodity incentivizes CO(2) removal to mitigate climate change. The synthesis allows morphology control at the liquid/solid interface that is not available through conventional CVD synthesis at the gas/solid interface. Natural abundance (12)CO(2) forms hollow CNTs, while equivalent synthetic conditions with heavier (13)CO(2) favours closed core CNFs, as characterized by Raman, SEM and TEM. Production ease is demonstrated by the first synthesis of a pure (13)C multiwalled carbon nanofiber.