Facile Synthesis of Millimeter-Scale Vertically Aligned Boron Nitride Nanotube Forests by Template-Assisted Chemical Vapor Deposition

Abstract

There is an increasing amount of research interest in synthesizing boron nitride nanotubes (BNNTs) as well as BN coatings to be used for various applications due to its outstanding mechanical, electrical and thermal properties. However, vertically aligned (VA) BNNTs are difficult to synthesize and the longest VA-BNNTs achieved to date are up to several tens of microns. Here, we report the synthesis of over millimeters long multi-walled BN coated carbon nanotubes (BN/CNT) and BNNT forests via a facile and effective two-step route involving template-assisted chemical vapor deposition at a relatively low temperature of 900 °C and subsequent annealing process. The as-prepared BN/CNTs and BNNTs retain the highly ordered vertically aligned structures of the CNT templates as identified by scanning electron microscopy.The structure and composition of the resulting products were studied using transmission electron microscopy, electron energy-loss spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. This versatile BN coating technique and the synthesis of millimeter-scale BN/CNTs and BNNTs pave a way for new applications especially where the aligned geometry of the NTs is essential such as for field-emission, interconnects and thermal management.

Coaxial carbon@boron nitride nanotube arrays with enhanced thermal stability and compressive mechanical properties

“…Fabrication of C@BNNT arrays C@BNNT arrays were prepared by TCVD according to a previously reported method with slight modification. 55 Briefly, the CNT samples on the Si wafer were firstly located in the central part of a horizontal reaction tube and boric acid powder with a specified amount was loaded at one end of the tube, followed by heating up to 150°C for 10 min and holding for 30 min under flowing Ar (300 sccm). The temperature was then ramped up to 830°C in 90 min and retained for another 30 min.…”

Dynamic thin film mediated slicing of boron nitride nanotubes

“…[52][53][54] However, the ATR-FTIR for BNNTs aer slicing has other peaks at 3400 cm À1 , 2920-2850 cm À1 , 1100 cm À1 and 1020 cm À1 corresponding to O-H and C-H stretching, C-O stretching (secondary alcohol) and C-H bending modes respectively for IPA 59,60 The Raman spectrum of BNNTs has one peak for the B-N E 2g symmetry mode at 1359.5 cm À1 . 49,50,53,61 Aer processing in the VFD at the optimum conditions, the peak for the B-N E 2g mode is unperturbed, Fig. 6(c), 23 but now with an additional peak for included IPA at 2872.5 cm À1 .…”

Wafer-scale on-chip synthesis and field emission properties of vertically aligned boron nitride based nanofiber arrays

“…Much effort has been devoted to the synthesis of BN nanotubes (BNNTs) since their initial discovery in 1995. [11][12][13][14][15][16][17][18][19] Multiple synthesis methods have been employed, including arc discharge, chemical vapor deposition, carbon nanotube conversion, laser vaporization, and inductively coupled plasma synthesis. [12][13][14][15][16][17][18][19] Far less attention has been paid to the development of 1D BN nanofibers (BNNFs) or nanowires (BNNWs).…”

“…[11][12][13][14][15][16][17][18][19] Multiple synthesis methods have been employed, including arc discharge, chemical vapor deposition, carbon nanotube conversion, laser vaporization, and inductively coupled plasma synthesis. [12][13][14][15][16][17][18][19] Far less attention has been paid to the development of 1D BN nanofibers (BNNFs) or nanowires (BNNWs). Nevertheless, the synthesis of BNNFs and BNNWs has yielded some encouraging results, [20][21][22][23] and the scalable creation of vertically aligned BNNFs on-chip would be a significant advance, especially if the orientation, dimensionality, and location of the nanofibers could be controlled.…”

“…This reaction has been previously used to convert graphene into h-BN or forming coatings on carbon nanotubes at low temperature. 16,[31][32][33] Using ammonia as a reaction gas instead of nitrogen is also effective, and this can significantly decrease the carbon substitution reaction temperature. In this case, the glassy carbon fiber array is loaded into the high temperature zone of the furnace and heated to a high temperature of 1000-1200 C with ammonia flow (100 sccm) for 20 min, while boric acid in the low temperature zone is heated to 500 C. During the reaction, boron and nitrogen atoms gradually replace carbon atoms and form h-BN.…”