Understanding Electrochemical Growth of Carbon Nanotubes from CO2

Abstract

Previous works have pioneered the observation of carbon nanotube growth in molten LiCO3 electrolytes from CO2. However in many past works, several CO2-derived cathodic carbon morphologies were observed, which included carbon particles/spheres, graphite flakes, carbon nanofibers, CNTs, and graphene-like ultrathin carbon sheets. Moreover, these morphologies are often mixed, resulting in a low selectivity and difficult separation towards one single carbon morphology, and the factors leading to various morphologies are not currently well understood. In this talk, we will explore the fundamental growth mechanism to inform the broader long-term goal of improving the selectivity towards carbon nanotubes from CO2. This present work studied the cathodic growth of carbon nanotubes by utilizing a simple three-electrode configuration consisting of pure Li2CO3 electrolyte, pure transition metal foil cathodes, Pt anode, and homemade Ag/Ag2SO4 reference electrode to determine the impact of tunable parameters on the resulting electroreduction products.