关键词: 纳米片, 碳化钛, 炭黑, 熔盐合成

Abstract:

2D transition metal carbides are very attractive nanomaterials due to their unique properties.Using carbon black and Ti₃AlC₂ powder as raw materials,it was expected that Ti₃AlC₂ can be reduced by carbon in a molten salt environment to syn-thesize titanium carbide（TiC） nanosheets.The results showed that carbon black may induce the decomposition of Ti₃AlC₂ to syn-thesize TiC nanocrystals at low temperature.As the heating temperature increased,the degree of decomposition of Ti₃AlC₂ was gradually intensified.Ti₃AlC₂ could be seriously decomposed into Al,Ti,Ti_2.9Al_2.1 and TiC at low temperature（1 000~1 100 ℃）.Al and Ti could react with trace oxygen to produce a small amount of TiO₂ and Al₂O₃.The generated TiC was nano-particle.The introduction of molten salt was a necessary condition to ensure the formation of TiC nanosheets.By optimizing the preparation process,the most suitable conditions for the synthesis of high content TiC nanosheets were obtained.The molar ra-tio of carbon black to Ti₃AlC₂ was 1.05∶1,and the mass ratio of NaCl to KCl was 1∶1.The mass ratio of the total salt to the mix-ture of carbon black and Ti₃AlC₂ was 2∶1.The mixed powders were put into the tubular furnace under the protection of Ar.After holding at 1 000 ℃ for 2 h,the samples with TiC as the main component were obtained by molten salt heat treatment.The morphology of TiC was fine nanosheets with thickness of about 10 nm and length of about 170 nm.

Key words: nanosheets, TiC, carbon black, molten salt synthesis