Covalently Bonded Three-Dimensional Carbon Nanotube Solids via Boron-Induced Nanojunctions

D.P. Hashim,1 N.T. Narayanan,1 J.M. Romo-Herrera,2 D.A. Cullen,3 M.G. Hahm,1 P. Lezzi,4 J. R. Suttle,1 D. Kelkhoff,5 E. Munoz-Sandoval,6 S. Ganguli,7 A.K. Roy,7 D.J. Smith,8 R. Vajtai,1 B.G. Sumpter,3 V. Meunier,4 H. Terrones,3,9 M. Terrones,10 P.M. Ajayan1

1-Rice University, Houston, TX
2-Universidade de Vigo, Spain
3-Oak Ridge National Laboratory, Oak Ridge, TN.
4-Rensselaer Polytechnic Institute, Troy, NY
5-University of Illinois, Urbana, IL
6-Instituto de Microelectro´nica de Madrid, Tres Cantos, Spain
7-Air Force Research Laboratory, Dayton, OH
8-Arizona State University, Tempe, AZ
-9Universite´ Catholique de Louvain, La Neuve, Belgium
10-The Pennsylvania State University, University Park, PA. and Shinshu University, Nagano, Japan

Achievement
Collaborative nanoscience research between multiple institutions has pioneered the bulk synthesis of 3-dimensional (3D) macroscale nanotube elastic solids directly via a boron-doping strategy in chemical vapor deposition. The boron-doping strategy influences the formation of atomic-scale ‘‘elbow’’ junctions and nanotube covalent interconnections. This effect of boron doping was elucidated from detailed theoretical calculations validated by elemental analysis, revealing that boron promotes formation of negative curvature “elbow’’ junctions that leads to robust interwoven “sponge-like” 3D network material, exhibiting ultra light weight, super hydrophobicity, high porosity, thermal stability, mechanical flexibility, and strong oleophilicity. These properties enable it to be used as a reusable sorbent scaffold for efficiently removing oil from contaminated seawater.

Significance
The new efficient, inexpensive and facile method is capable of producing bulk quantities of 3D carbon materials, with many practical material applications such as selective sorbent materials, hydrogen storage and flexible conductive scaffolds for porous 3D electrodes. The ultra-lightweight solid material exhibits robust elastic mechanical properties with high damping, electrical conductivity, thermal stability, high porosity, superhydrophobicity, oleophilic behavior and strong ferromagnetism. Oil removal-and-salvage from seawater was demonstrated, where the nanotube sponge acts as an efficient scaffold that can be controlled and recollected via a magnetically driven process, and reused multiple times.

Credit
This work was published in Nature Scientific Reports A portion of this Research at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

“Covalently bonded three-dimensional carbon nanotube solids via boron induced nanojunctions,” D.P. Hashim, N.T. Narayanan, J.M. Romo-Herrera, D.A. Cullen, M.G. Hahm, Peter Lezzi, Joseph R. Suttle, Doug Kelkhoff, E. Munoz-Sandoval,S. Ganguli, A.K. Roy, D.J. Smith, R. Vajtai, B.G. Sumpter, V. Meunier, H. Terrones, M. Terrones, P.M. Ajayan, Nature Sci. Rep. doi: 10.1038/srep00363 (2012).