Temperature-Dependent Morphology Evolution of Boron Nitride and Boron Carbonitride Nanostructures

Wei Li,Shuaifeng Chen,Huan Yang,Changjiu Li,Yongjun Chen,Lijie Luo,Qing Chen,Jianbao Li

doi:10.1155/2019/3572317

Abstract

Boron nitride (BN) and boron carbonitride (BCN) nanostructures with versatile morphology were synthesized at different temperatures. The morphologies such as smooth microspheres, nanoflake-decorated microspheres, solid nanowires, hollow nanotubes (bamboo-like nanotubes, quasi-cylindrical nanotubes, and cylindrical nanotubes), and nanosheet-assembled microwires have been observed. Systematic investigation showed that the reaction temperature was responsible for the versatile morphologies through influencing the guiding effect of catalyst alloy droplet and the diffusion rates of growth species. The diffusion rate differences between surface diffusion (along the surface of the droplet) and bulk diffusion (through the bulk of the droplet) at different reaction temperatures were suggested to affect the final structure of the BN and BCN nanostructures.

Highlights

Boron nitride nanotubes (BNNTs) are structural analogues of carbon nanotubes (CNTs), alternating B and N atoms entirely substitute for C atoms in a graphitic-like sheet with almost no change in atomic spacing
Ternary boron carbonitride nanotubes (BCNNTs), have tunable bandgaps determined merely by their chemical composition rather than geometrical structure, which is superior to the CNT and BNNT counterparts [13,14,15]
Bamboo-like BCN nanotubes were mainly formed when the reaction temperature was 1000°C (Figure 6(a)), and both bamboo-like and quasi-cylindrical BCN nanotubes coexisted when the temperature rose to 1100°C (Figures 6(b)–6(d)), while cylindrical BCN nanotubes were synthesized if the temperature further increased to 1200°C (Figure 6(e))

Summary

Introduction

Boron nitride nanotubes (BNNTs) are structural analogues of carbon nanotubes (CNTs), alternating B and N atoms entirely substitute for C atoms in a graphitic-like sheet with almost no change in atomic spacing. Ternary boron carbonitride nanotubes (BCNNTs), have tunable bandgaps determined merely by their chemical composition rather than geometrical structure, which is superior to the CNT and BNNT counterparts [13,14,15]. This gives BCNNTs potential applications in the fields of electrical conductors, electronic devices, photoluminescent materials, and catalysts [15,16,17]. It has been noted that reaction temperature dramatically affected the formation and morphology of BN or BCN nanostructures [30,31,32,33]. The morphology evolutions of BN and BCN nanostructures and their relationship with reaction temperature have been studied systematically

The Morphological Evolution of BN and BCN Nanostructures

Morphology Evolution Mechanism

Conclusions