Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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A study on the Ni formation by reduction of NiO nano crystals

NiO 나노 결정의 환원 반응에 의한 Ni 형성 거동에 관한 연구

  • Kim, Chang-Sam (Korea Institute of Science and Technology) ;
  • Kang, Seung-Min (Department of Advanced Materials Science and Engineering, Hanseo University)
  • Published : 2009.10.31
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Abstract

The Ni formation behavior from the reduction of NiO nano crystals in the $H_2/N_2$ gas mixtures. The NiO nano crystals were synthesized by heat-treating nickel nitrate$(Ni(NO_3)_2\cdot6H_O)$ in the air at $500^{\circ}C$, and had an octahedral shape and the particle size of 200~500 nm. The NiO nano-crystals had well-developed (111) planes which is hardly formed in normal synthetic conditions. The reduction process was carried out at 300 and $600^{\circ}C$ for 15 and 60 minutes, respectively. When the NiO nano-crystals were reduced at $300^{\circ}C$, the Ni particles sustained the same octahedral shape as NiO, while Ni particles were to agglomerate at $600^{\circ}C$.

NiO 나노 결정을 수소 분위기에서 환원시켜 Ni 금속이 형성되는 거동에 대하여 고찰하였다. NiO 나노 결정은 $Ni(NO_3)_2\cdot6H_2O$를 열처리하여 얻었고, 200~500 nm의 입도와 정 팔면체의 형상을 나타내었다. 이 결정은 일반적인 합성조건에서는 잘 형성되지 않는 불안정 상태인 불안정상태인 (111)면이 발달한 결정체였다. 환원은 300과 $600^{\circ}C$에서 15분과 60분간 수행하였다. NiO 결정의 환원은 불안정한 (111)면에서 우선적으로 일어나기 시작하였으며, $300^{\circ}C$ 환원에서는 팔면체 형상을 유지하면서 Ni로 환원되었다. $600^{\circ}C$ 환원에서는 팔면체 결정의 facet 면이 사라지고, 인접한 결정립들 간의 neck가 형성되면서 Ni 상의 입자로 응집되어가는 것을 확인하였다.

Keywords

References

  1. S. Doppiu, V. Langlais, J. Sort, S. Surinach, M.D. Baro, Y. Zhang, G. Hadjipanayis and J. Nogues, "Controlled reduction of NiO using reactive ball milling under hydrogen atmosphere leading to Ni-NiO nanocomposites", Chem. Mater. 16 (2004) 5664 https://doi.org/10.1021/cm048810n
  2. H. Yan, C.F. Blanford, B.T. Holland, M. Parent, W.H. Smyrl and A. Stein, "A chemical synthesis of periodic macriporous NiO and metallic Ni", Adv. Mater. 11 (1999) 1033
  3. J.A. Rodriguez, J.C. Hanson, A.I. Frenkel, J.Y. Kim and M. Perez, "Experimental and theoretical studies on the reaction of H$_2$ with NiO: role of O vacancies and mechanism for oxide reduction", J. Am. Chem. Soc. 124 (2002) 347 https://doi.org/10.1021/ja0121080
  4. S. Berchmans, H. Gomathi and G.P. Rao, "Electrooxidation of alcohols and sugars catalysed on a nickel oxide modified glassy carbon electrode", J. Electroana. Chem. 394(1-2) (1995) 267 https://doi.org/10.1016/0022-0728(95)04099-A
  5. B. Alcock, Baozhen Li, J.W. Fergus and L. Wang, "New electrochemical sensors for oxygen determination", Solid State Ionics 53 (1992) 39 https://doi.org/10.1016/0167-2738(92)90362-S
  6. A. Aronin, G. Abrosimova, S. Bredikhin, K. Matsuda, K. Maeda and M. Awano, "Aging of the NiO-YSZ working electrode of the electrochemical cell for NO decomposition", J. Cer. Soc. Jap. 110(8) (2002) 1284
  7. A. Aronin, G. Abrosimova, S. Bredikhin, K. Matsuda, K. Maeda and M. Awano, "Aging of the NiO-YSZ working electrode of the electrochemical cell for NO decomposition", J. Cer. Soc. Jap. 110(8) (2002) 1284
  8. A. Barbier, C. Mocuta and G. Renaud, "Structure, transformation, and reduction of the polar NiO (111) surface", Phys. Rev. 62 (2000) 16 056 https://doi.org/10.1103/PhysRevB.62.16056
  9. M. Cowley, "Surface energies and surface structure of small crystals studied by use of a stem instrument", Surf. Sci. 114 (1982) 587 https://doi.org/10.1016/0039-6028(82)90707-5
  10. P.M. Oliver, G.W. Watson and S.C. Parker, "Moleculardynamics simulations of nickel oxide surface", Phys. Rev. B 52 (1995) 5323 https://doi.org/10.1103/PhysRevB.52.5323
  11. A. Matsuda, S. Akiba, M. Kasahara, T. Watanabe, Y. Akita, Y. Kitamoto, T. Tojo, H. Kawaji, T. Atake, K. Koyama and M. Yoshimoto, "Fabrication of ferromagnetic Ni epitaxial thin film by way of hydrogen reduction of NiO", Thin Solid Films 516 (2008) 3873 https://doi.org/10.1016/j.tsf.2007.07.133
  12. A. Szekely, C.I. Lin and H.Y. Sohn, "A structural model for gas-solid reaction with a moving boundary-V an experimental study of the reduction of porous nickel-oxide pellets with hydrogen", Chem. Eng. Sci. 28 (1973) 1975 https://doi.org/10.1016/0009-2509(73)85042-0
  13. T.A. Utigard, M. Wu, G. Plascencia and T. Marin, "Reduction kinetics of goro nickel oxide using hydrogen", Chem. Eng. Sci. 60 (2005) 2061 https://doi.org/10.1016/j.ces.2004.11.024