Simple and rapid conversion of silicon carbide to nanodiamonds at ambient pressure  

作　　者：Cheng Yang Bingqiang Wei Kejian He Ping Xu Xiangmin Xie Kai Tong Chen Zeng Yafeng Wang Xiaodong Wang Jinping Liu Mingyu Zhang Zhe'an Su Qizhong Huang 

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]Advanced Research Center.Central South University,Changsha 410083,China [3]Hunan Changyu Science and Technology Development Co.,Ltd.,Changsha 410600,China

出　　处：《Journal of Materials Science & Technology》2021年第35期230-238,共9页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.U19A2088);the Special Fund for Innovative Construction of Hunan Province(No.2019RS2058)。

摘　　要：Nanodiamonds(NDs)were prepared under ambient pressure by sublimation decomposition of silicon carbide in an intermediate frequency furnace for only 8 min.The synthesis proceeded in the temperature range of 2600-2800℃ without any catalyst or highly active gas components(such as H2,alkane,and halogen).The conversion began at 2600℃ and produced NDs with particle sizes in the range of 1-5 nm with a uniform particle shape and excellent dispersion.The linear reaction kinetics allowed for rapid transformation to any depth with reasonable control of the temperature.The linear rate constant(K_(l))for the reaction at 2800℃ was 37.5 mm/h,which is 31.2 times that of the reaction at 2600℃.The Si C sublimation decomposition produced carbon atoms that filled the Si C lattice vacancies or were combined with the suspended carbon chain bonds to form sp3 carbon,while the diffusion of amorphous carbon atoms promoted nucleation and growth of diamond.High-resolution transmission electron microscopy analysis indicated that the NDs were separated from the Si C matrix by break-off due to propagation of the reaction front.This Si C sublimation decomposition method is considered simple,fast,environmentally friendly and promising for industrial-scale production.

关 键 词：n-diamond SiC NANODIAMOND Sublimation decomposition 

分 类 号：TB383.1[一般工业技术—材料科学与工程] TQ163[化学工程—高温制品工业]