Low-temperature growth of carbon nanotubes catalyzed by sodium-based ingredients
Renu Sharma, Richard Li, Erica F. Antunes, Estekke Cohen, Akira Kudo, Luiz Acauan, Wei-Chang D. Yang, Chih-Ming Wang, Kehang Cui, Andrew Liotta, Ananth G. Rajan, Jules Gardner, David C. Bell, Michael S. Strano, James A. Liddle, Brian L. Wardle
Nanoparticle-catalytic synthesis of carbon nanostructures is an attractive route for producing 1-dimensional carbon nanomaterials, such as carbon nanotubes1 (CNTs), in large enough quantities for their multifunctional capabilities to be applied in aerospace composites, energy storage2, and computing, among others3-9. Here, we report facile low-temperature synthesis of CNTs from common household sodium-based compounds including NaHCO3, Na2CO3, NaOH, and NaCl, found in baking soda, detergents, and table salt, respectively. Coupled with an oxidative dehydrogenation reaction10 to crack acetylene at reduced temperatures, sodium metal nanoparticles catalyze CNT growth at temperatures below 400 °C. Ex situ and in situ transmission electron microscopy is utilized to characterize the spatial composition of the CNTs and catalytically active sodium particles during growth. Unique CNT morphologies and growth phenomena are observed, including a vanishing catalyst phenomenon: purified CNTs sans residual catalyst particles are obtained for use in applications where metal catalysts are considered contaminants. The sodium catalyst is shown to synthesize CNTs on numerous substrates, and as the first alkali group metal catalyst, holds great promise for expanding the current space for CNT growth.