摘要
建立了一种不同催化剂含量下以无定形硼粉、活性碳粉、九水硝酸铁(催化剂)和尿素为原料的共沉淀-退火两步反应制备BN纳米管的方法。研究发现:催化剂含量的变化会影响BN纳米管的形貌和产量。当催化剂含量较低(摩尔比Fe(NO3)3/B=0.05)时,只有少量的竹节状纳米管生成,无颗粒存在,纳米管的平均直径约100nm。随着催化剂含量的升高(摩尔比Fe(NO3)3/B=0.1),纳米管的产量也升高,但有少量的颗粒形成,纳米管的平均直径仍然为约100nm。而当催化剂含量变得更高(摩尔比Fe(NO3)3/B=0.2)时,纳米管表面沉积着一层纳米片,管径升至250nm以上,同时颗粒也增多。分析表明纳米管的生长机理为气-液-固(VLS)生长机制。
Boron nitride(BN) nanotubes were synthesized via a co-precipitation and annealing two-step method,using amorphous boron powder,activated charcoal powder,iron nitrate nonahydrate(Fe(NO3)3·9H2O) and urea(CO(NH2)2) as the raw materials.The effects of catalyst(Fe(NO3)3·9H2O) content on morphology and yield of boron nitride nanotubes were investigated.It is found that when the catalyst content was little(the molar ratio of Fe(NO3)3/B is 0.05),pure bamboo-like BN nanotubes with average diameter of about 100 nm were obtained,but the yield was low.When the molar ratio of Fe(NO3)3/B increased to 0.1,the yield of BN nanotubes increased and the average diameter of the nanotubes was still about 100 nm.However,a small amount of particles were formed in addition to BN nanotubes.When the molar ratio of Fe(NO3)3/B further increased to 0.2,BN nanotubes with nanosheets depositing on the surfaces were found.The average diameter of the product increased to more than 250 nm and the quantity of particles also increased.The BN nanotubes are believed to grow via a vapor-liquid-solid(VLS) model.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2013年第4期557-561,共5页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(51162001)
关键词
氮化硼纳米管
制备
九水硝酸铁
生长机理
BN nanotubes
synthesis
iron nitrate nonahydrate
growth mechanism