埋碳条件下石墨烯与硅粉反应过程研究

Reaction process of graphene and silicon powder under carbon embedded condition

为探究埋碳条件下石墨烯与硅粉的反应过程,对多层石墨烯(层数<30)和w(Si)=99.47%的硅粉于不同温度下(1000、1100、1200、1300、1400、1500、1600℃)热处理3 h,结合反应后试样的物相组成和显微结构,对试样的反应过程进行热力学分析和机制探究。结果表明:1)热处理温度为1000℃时,试样中出现了以SiC为晶核的无定形SiO_(2)微球;2)热处理温度为1200℃时,生成以SiC纳米线为桥和桥上的无定形SiO_(2)球体构成的串珠状晶须;3)热处理温度<1400℃时,SiO_(2)微球和串珠状晶须的含量、直径均随着温度的升高逐渐增大;4)热处理温度为1500℃时,发生碳热还原反应,无定形SiO_(2)含量逐渐减少,SiC纳米线含量增多;5)热处理温度为1600℃时,试样内均是SiC纳米线,且SiC纳米线的生长主要遵循气-固反应机制。

In order to explore the reaction process of graphene and silicon powder under carbon embedded condition,the multi-layer graphene(layer number<30)and silicon powder(99.47% by mass)were heat treated at different temperatures(1000,1100,1200,1300,1400,1500,and 1600℃)for 3 h.Combined with the phase composition and the microstructure of the samples,the thermodynamic analysis and the mechanism investigation were conducted.The results show that:(1)when the sample is heat treated at 1000℃,amorphous SiO_(2)microspheres with SiC crystal nucleus appear;(2)at 1200℃,bead-like whiskers form,which are made of SiC nanowires bridge and the amorphous SiO_(2)spheres on the bridge;(3)when the hot treatment temperature is lower than 1400℃,the content and the diameter of SiO_(2)microspheres and bead-like whiskers gradually increase with temperature rising;(4)at 1500℃,carbothermic reduction reaction occurs,amorphous SiO_(2)gradually decreases,and the SiC nanowire content increase;(5)at 1600℃,there are all SiC nanowires in the samples,and the growth of SiC nanowires mainly follows the gas-solid reaction mechanism.