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研究在N2O/N2/NH3氛围中对Ni催化剂进行退火处理,旨在探讨退火处理对所生成碳纳米管的表面结构及其发射特性的影响。从表面结构及表面元素分析结果发现:Ni催化剂在N2O/N2/NH3氛围中退火处理之后,Ni催化剂的颗粒大小及催化剂的化学成分发生改变,进而影响所合成的碳纳米管的表面结构及场发射特性。扫描电镜显示:经过N2O退火前处理后,催化金属薄膜在成核时较易形成均匀性的金属颗粒,且金属颗粒较小。比较经N2O/N2/NH3氛围退火处理之后所合成的碳纳米管结果,经过N2O前处理可以有效抑制非晶质碳的成长,使所成长出的碳纳米管数量最多、场发射电流最大。原因主要是因为N2O对催化剂镍膜金属前处理过程中分解出的氮原子及氧原子会活化及氧化催化剂Ni金属,并使所形成的Ni金属颗粒较小且更为均匀,造成表面型态上的显著改变,有助于使合成的碳纳米管场发射电流变大。
The effect of annealing treatment on the surface structure and emission characteristics of the resulting carbon nanotubes was investigated by annealing the Ni catalyst in a N2O / N2 / NH3 atmosphere. From the surface structure and surface elemental analysis results, it is found that the Ni catalyst particle size and the chemical composition of the catalyst change after the Ni catalyst is annealed in a N2O / N2 / NH3 atmosphere, thereby affecting the surface structure and field of the synthesized carbon nanotube Emission characteristics. Scanning electron microscopy showed that after the pretreatment with N2O annealing, the catalytic metal thin film is easier to form uniform metal particles during nucleation, and the metal particles are smaller. Comparing the results of carbon nanotubes synthesized after annealing in N2O / N2 / NH3 atmosphere, N2O pretreatment can effectively inhibit the growth of amorphous carbon, resulting in the largest number of carbon nanotubes grown and the largest field emission current. The main reason is that N2O decomposes nitrogen atoms and oxygen atoms during the pretreatment of the catalyst nickel membrane metal to activate and oxidize the catalyst Ni metal and make the Ni metal particles formed smaller and more uniform, Of the significant changes, help to make the synthetic carbon nanotube field emission current larger.