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在对不同温度和不同催化剂对硼碳氮 (BCN)生长影响研究的基础上 ,进一步研究了氮气与氢气对高温热解法制备BCN纳米管结构、产量等的影响 .实验中发现氮气在制备过程中只对BCN纳米管的产量有微小影响 ,对所生成的纳米管的结构有一定影响 ,气流量太小时 ,乙二胺的转化率低 ,气流量太大时 ,会在所生成的BCN纳米管管壁上出现断裂生长现象 .与氮气不同的是氢气不仅对所生成的纳米管的结构有很大影响 ,还对产量有明显影响 ,当制备过程中没有氢气时 ,所生成的BCN纳米管有明显的弯曲 ,甚至出现了急剧的弯折 ,大部分管壁附着无定形碳 ,还伴随中空管的出现 ;当氢气流量为 4 0sccm时 ,所生成的BCN纳米管的管壁较薄 ,管壁平滑干净 ,没有明显的无定形碳 ,“竹节”规律性较强 ,而当氢气流量继续增大至 80sccm时 ,所生成的BCN纳米管管壁较氢气流量为 4 0sccm时更薄 ,但是此时生成的纳米管的“竹节”变厚 ,并且更加弯曲 ,但是间距规律性减弱 ,在有些纳米管的管壁也出现了断裂现象 .根据实验分析 ,认为在高温热解法制备BCN纳米管时 ,氮气流量应该控制在 15 0— 2 10sccm范围内 ,氢气流量应该在 4 0sccm附近 .对氮气和氢气的影响机理进行了讨论
The effects of nitrogen and hydrogen on the structure and yield of BCN nanotubes prepared by high temperature pyrolysis were further studied based on the studies on the effects of different temperatures and different catalysts on the growth of BCN.The results showed that during the preparation process Only a slight impact on the yield of BCN nanotubes, the structure of the resulting nanotubes have a certain impact, the gas flow is too small, ethylenediamine conversion is low, the gas flow is too large, will be generated in the BCN nano Fracture growth appears on the wall of the tube. Unlike nitrogen, hydrogen not only has a significant effect on the structure of the nanotubes produced, but also has a significant effect on the yield. When there is no hydrogen in the preparation process, the generated BCN nanotubes There are obvious bending, even sharp bend, most of the wall attached to the amorphous carbon, but also with the emergence of hollow tube; when the hydrogen flow rate of 40sccm, the resulting BCN nanotubes thinner wall, The wall of the tube was smooth and clean with no obvious amorphous carbon. The regularity of “bamboo” was strong. When the hydrogen flow rate continued to increase to 80sccm, the wall of the generated BCN nanotube was thinner than the flow rate of 40 sccm of hydrogen. but At this time, the “bamboo” of the nanotubes formed was thicker and more curved, but the regularity of the spacing was weakened, and the rupture appeared on some of the nanotubes.According to the experimental analysis, it was considered that BCN In the case of nanotubes, the nitrogen flow rate should be controlled in the range of 15 0 - 2 10sccm and the hydrogen flow rate should be in the vicinity of 40 sccm. The mechanism of the effects of nitrogen and hydrogen is discussed