EFFECT OF H2 REDUCTION ON CARBON NANOTUBE SYNTHESIS

Year 2012, Volume: 2 Issue: 2, 20 - 25, 23.07.2016

Nazlı Çınar Neslihan Yuca Nilgün Karatepe

Abstract

Carbon nanotubes (CNTs) with their high mechanical, electrical, thermal and chemical properties are regarded as promising materials for many different potential applications. Chemical vapor deposition (CVD) is a common method for CNT synthesis especially for mass production. There are important parameters (synthesis temperature, catalyst and calcination conditions, substrate, carbon source, synthesis time, H2 reduction, etc.) affecting the structure, morphology and the amount of the CNT synthesis. In this study, CNTs were synthesized by CVD of acetylene (C2H2) on magnesium oxide (MgO) powder substrate impregnated by iron nitrate (Fe (NO3)3•9H2O) solution. The synthesis conditions were as follows: at catalyst calcination temperatures of 400 and 550°C, calcination time of 0, 15 and 30 min, hydrogen concentrations of 0, 5, 10, 20, 50 and 100 % vol, synthesis temperature of 550°C and synthesis time of 30 minutes. The synthesized materials were characterized by thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and Raman spectroscopy. Effect of H2 reduction on catalyst calcination and CNT synthesis were investigated

Keywords

H2, reduction, carbon nanotubes, CVD, synthesis, fluidized bed

References

• Chang Chung, Uoo.(2004). Effect of H2 on formation behavior of carbon nanotubes. Bull. Korean Chem. Soc,25,1521-1524
• Corrias,M.,Caussat,B.,Ayral,A.,Durand,J.Kihn,Y.,Kalck,Ph.,Serp,Ph.(2003).Carbon nanotubes produced by fluidized bed catalytic CVD: first approach of the process.Chem. Eng. Sci,58,4475－4482.
• Guo,T., Nikolaev,T.P.,Thess,A.(1996).Chem.Phys.Lett,260,471. Hernadi,K, Fonseca,A., Nagy,J.B.,Siska,A., Kiricsi,I.(2000).Appl.Catal.A,199,245.
• Iijima, S.(1991).Helical microtubules of graphitic carbon.Nature, 354,56-58 Kim, Jin Suk Calvin.(2006).The role of hydrogen in the growth of carbon nanotubes: a study of the catalyst state and morphology, Massachusetts Institute of Technology,B.Sc.Thesis.
• Maiti,A.,Brabec,C.J.,Rol,C.M.,Bernhole,J.(1994).Phys.Rev.Lett,73,2468. Pérez-Cabero,M.,Rodríguez-Ramos, I., Guerrero-Ruíz,A.(2003).Characterization of carbon nanotubes and carbon nanofibers prepared by catalytic decomposition of acetylene in a fluidized bed reactor.J. Catal, 215,305-316.
• Piao,Lingyu.,Li,Yongdan.,Chen,Jiuling.,Chang,Liu.,Lin,Jerry.Y.S.(2002).Methane decomposition to carbon nanotubes and hydrogen on an alumina supported nickel aerogel catalyst, Catalysis Today,74,145-155.
• Qian ,W., Liu,T.,Wang,Z.,Wei,F.,Li,Z.,Luo,G.,Li,Y.(2004).Production of hydrogen and carbon nanotubes from methane decomposition in a two-stage fluidized bed reactor. Appl. Catal. A,260,223-228.
• Trimm, D.L.(1977).Catal. Rev Sci. Eng,16,155. Uoo-Chang C. (2004). Effect of H2 on Formation Behavior of Carbon Nanotubes. Bull. Korean Chem. Soc.;25,10:1521