Synthesis of boron nitride in tubular form

Abstract

A simple method for synthesizing boron nitride in tubular form, iron oxide-assisted chemical vapor transport, was demonstrated. Filamentous and nanotubular boron nitride can be obtained by heating the mixture of boron and iron oxide with a weight ratio of 15:1 in a flowing ammonia gas. The growth of the filamentous BN with diameters ranging from 60 to 110 nm involves a vapor–liquid–solid mechanism. Unlike the morphology of filament, BN nanotubes have the smaller diameters ranging from 7 to 30 nm and no metal particles are wrapped in their ends. The growth mechanism of BN nanotubes was also discussed.