DOI QR코드

DOI QR Code

주형합성을 통한 메조포러스 TiO2 제조 및 실리카 메조포어 내부에서의 TiO2 상전이 거동 변화

Preparation of Mesoporous Titanium Oxides by Template Synthesis and Phase Transition of TiO2 inside Mesoporous Silica

  • 방경민 (전남대학교 화학공학과) ;
  • 김영지 (전남대학교 화학공학과) ;
  • 김승한 (과학영재학교 광주과학고등학교) ;
  • 최예락 (과학영재학교 광주과학고등학교) ;
  • 이인호 (과학영재학교 광주과학고등학교) ;
  • 고창현 (전남대학교 화학공학과)
  • Bang, Gyeong-Min (Department of Chemical engineering, Chonnam National University) ;
  • Kim, Young-Ji (Department of Chemical engineering, Chonnam National University) ;
  • Kim, Seung Han (Gwangju Science Academy for the Gifted) ;
  • Choi, Yerak (Gwangju Science Academy for the Gifted) ;
  • Lee, In Ho (Gwangju Science Academy for the Gifted) ;
  • Ko, Chang Hyun (Department of Chemical engineering, Chonnam National University)
  • 투고 : 2017.09.11
  • 심사 : 2017.10.16
  • 발행 : 2018.04.01

초록

본 연구에서는 수열합성법과 주형합성법을 이용하여 메조포어를 지닌 $TiO_2$를 합성하였다. 수열합성법을 이용해서 anatase 구조의 메조포러스 $TiO_2$를 합성했다. Rutile 구조의 메조포러스 $TiO_2$를 제조하기 위해서 수열합성법으로 제조된 메조포러스 $TiO_2$$300^{\circ}C$부터 $700^{\circ}C$까지 소성시켰더니 $600^{\circ}C$부터 anatase에서 rutile 결정구조로 상전이가 일어났다. 하지만, 메조포어가 붕괴되었다. 메조포어을 지닌 $TiO_2$를 합성하기 위해서 메조포러스 실리카 KIT-6을 주형으로 사용하는 주형합성법을 사용하였다. 먼저 메조포어 내부에 $TiO_2$를 형성시키고 소성온도를 800, $900^{\circ}C$로 높여서 anatase에서 rutile로의 상전이 거동을 조사하였다. 수열합성을 통해 제조된 자유로운 상태의 메조포러스 $TiO_2$의 경우 $600^{\circ}C$에서 anatase에서 rutile로의 상전이가 일어났지만 제한된 공간인 메조포러스 기공 내부에 형성된 $TiO_2$의 경우 $800^{\circ}C$까지 가열하더라도 rutile구조로 상전이가 일어나지 않았고, $900^{\circ}C$로 소성시키자 일부의 anatase가 rutile로의 상전이가 일어나기 시작하였다. 이러한 상전이는 산소 빈자리의 형성에 의해서 일어나야 한다고 알려져 있지만 실리카 기공 내부에 형성된 $TiO_2$는 실리카 기공 표면이 산소 빈자리 형성을 방해해서 상전이가 억제되는 것으로 판단된다. $900^{\circ}C$의 높은 소성온도로 인해서 anatase와 rutile 구조가 섞여있으며 실리카 기공 내부에 형성된 $TiO_2$는 NaOH 수용액을 이용해서 주형인 KIT-6과 분리해서 메조포어를 지닌 $TiO_2$를 제조하였다.

To prepare mesoporous $TiO_2$ ($meso-TiO_2$) with anatase and rutile crystal structures, hydrothermal and template synthesis were used. $Meso-TiO_2$ with anatase structure was obtained by hydrothermal synthesis. The crystal structure of $meso-TiO_2$ by hydrothermal synthesis converted from anatase to rutile by simple heating at $600^{\circ}C$ and above. However, their mesopore structure collapsed due to phase transition. To prepare $meso-TiO_2$ with rutile structure, template synthesis method was applied using mesoporous silica KIT-6 as a template. Once we incorporated anatase $TiO_2$ inside mesopores of silica, the phase transition temperature of $TiO_2$ confined inside KIT-6 was much higher ($900^{\circ}C$) than that of free-standing $TiO_2$ ($600^{\circ}C$). The suppression of $TiO_2$ phase transition inside mesopores of KIT-6 is closely related with the interaction between $TiO_2$ surface and silica walls in KIT-6 because oxygen vacancy in $TiO_2$ is regarded as the starting point for phase transition. After removal of silica template by NaOH solution washing, $meso-TiO_2$ with mixed phase between anatase and rutile was obtained.

키워드

참고문헌

  1. Kim, S. H., Na, S. E., Kim, S. Y., Kim, S. S. and Ju, C. S., "The Effect of Additives on the Preparation of Nanosized $TiO_2$ Particles," Korean Chem. Eng. Res., 51(4), 426-431(2013). https://doi.org/10.9713/kcer.2013.51.4.426
  2. Daghrir, R., Drogui, P. and Robert, D., "Modified $TiO_2$ For Environmental Photocatalytic Applications: A Review," Ind. Eng. Chem. Res., 52(10), 3581-3599(2013). https://doi.org/10.1021/ie303468t
  3. Chang, H. K., Jang, H. D., Park, J. H., Cho, K. and Kil, D. S., "Fabrication and Characteriztion of Porous $TiO_2$ Powder by Aerosol Process," Korean Chem. Eng. Res., 46(3), 479-485(2008).
  4. Hur, J. Y., Lee, H. I., Park, Y. K., Joo, O. S., Bae, G. N. and Kim, J. M., "Reproducible Synthesis of Periodic Mesoporous $TiO_2$ Thin Flim," Korean Chem. Eng. Res., 44(4), 399-403(2006).
  5. Kim, S. H., Jeong, S. G., Na, S. E., Kim, S. Y. and Ju, C. S., "Preparation of $TiO_2$ Powder by Hydrothemal Precipitation Method and their Photocatalytic Properties," Korean Chem. Eng. Res., 51(2), 195-202(2013). https://doi.org/10.9713/kcer.2013.51.2.195
  6. Kim, S. M., Yun, T. K. and Hong, D. I., "Effect of Rutile Structure on $TiO_2$ Photocatalytic Activity," The Korean Chemical Society, 49(6), 567-574(2005). https://doi.org/10.5012/jkcs.2005.49.6.567
  7. Oh, K. S., Yang, J. C., Jung, K. T., Choi, S. C. and Shul, Y. G., "Low Temperature Synthesis of Rutile $TiO_2$ in Sol-Gel with Organic Additives," HWAHAK KONGHAK, 33(5), 544-550(1995).
  8. Longoni, G., Lissette, R., Cabreara, P., Polizzi, S., D'Arienzo, M., Mari, C. M., Cui, Y. and Ruffo, R., "Shape-Controlled $TiO_2$ Nanocrystals for Na-Ion Battery Electrodes: The Role of Different Exposed Crystal Facets on the Electrochemical Properties," Nano Letters, 17(2), 992-1000(2017). https://doi.org/10.1021/acs.nanolett.6b04347
  9. Li, W., Wang, F., Liu, Y., Wang, J., Yang, J., zhang, L., Ahmed A. Elzatahry, Al-Dahyan, D., Xia, Y. and Zhao, D., "General Strategy to Synthesize Uniform Mesoporous $TiO_2$/Graphene/Mesoporous $TiO_2$ Sandwich-Like Nanosheets for Highly Reversible Lithium Storage," Nano Lett., 15(3), 2186-2193(2015). https://doi.org/10.1021/acs.nanolett.5b00291
  10. Lee, H. J., Park, N. K., Lee, T. J., Han, G. B. and Kang, M. S., "Effect of Particle Size and Structure of $TiO_2$ Semiconductor on Photoelectronic Efficienct of Dye-sensitized Solar Cell," Clean. Technology, 19(1), 22-29(2013). https://doi.org/10.7464/ksct.2013.19.1.022
  11. Iida, Y. and Ozaki, S., "Grain Growth and Phase Transformation of Titanium Oxide During Calcination," J. Amerian Ceramic Society, 44(3), 120-127(1961). https://doi.org/10.1111/j.1151-2916.1961.tb13725.x
  12. Mackenzie, K. J. D. and Melling, P. J., "The Calcination of Titania, II. Influence of Atmosphere on Crystal Growth in Anatase Powders," Trans. J. Br. Ceram. Soc., 73(6), 179-183(1974).
  13. Ha, C. S. and Park, S. S., "Adsorption of Various Metal Ions Using Mesoporous Materials," News & Info. for Chem. Eng., 30(1), 38- 42(2012).
  14. Jang, K. S., Cho, S. H., Song, M. G. and Kim, J. D., "Synthesis of Mesoporous $TiO_2$ Thin Films with Polypyrrole Nanoparticles by Ultrasonic-induced Polymerization," Korean Chem. Eng. Res., 46(4), 777-782(2008).
  15. Kang, M., Yi, S. H., Yie, J. E. and Kim, J. M., "Synthesis of Nanoporous Inorganic Materials Using Mesostructurd Carbon Template," Theories and Applications of Chem. Eng., 8(2), 2417- 2420(2002).
  16. Kang, J. P., Kim, S. T., Kim, H. S. and Kwon, Y. K., "Synthesis and Applications of Mesoporous Materials," Polymer Science and Technology, 15(3), 303-316(2004).
  17. Kim, J. M., "Preparation and Applications of Mesoporous Materials," Physics and High Technology, 13(7/8), 12-17(2004).
  18. Kim, H. J., Kwak, C. H., Suh, T. S. and Suhr, D. S., "Template Synthesis of Titania Nanostructures," HWAHAK KONGHAK, 40(3), 357-361(2002).
  19. Lee, C. M., Kim, J. W., Chang, H. W., Roh, K. M. and Jang, H. D., "Synthesis of Hollow Silica Particles from Soduim Silicate using Organic Template Particles," Korean Chem. Eng. Res., 53(1), 78-82(2015). https://doi.org/10.9713/kcer.2015.53.1.78
  20. W. B. Yue, X. X. Xu, J. T. S. Irvine, P. S. Attidekou, C. Liu, H. Y. He, and D. Y., "Mesoporous Monocrystalline $TiO_2$ and Its Solid-State Electrochemical Properties," Chem. Mater., 21, 2540- 2546(2009). https://doi.org/10.1021/cm900197p
  21. Kim, S. S., Hur, J. Y. and Kim J. M., "Fabrication of Dye-sensitized Solar Cell using Mesoporous $TiO_2$ Film," Advanced Engineering and Technology, 1(2), 251-254(2008).
  22. W. B. Yue, Chamnan Randorn, P. S. Attidekou, Zixue Su, John T. S. Irvine, and W. Zhou, "Syntheses, Li Insertion, and Photoactivity of Mesoporous Crystalline $TiO_2$," Advanced Functional Materials, 19(17), 2826-2833(2009). https://doi.org/10.1002/adfm.200900658
  23. Yoshitake Masuda, Kazumi Kato, "Synthesis and Phase Transformation of $TiO_2$ Nano-crystals in Aqueous Solutions," The Japan Ceramic Society, 117(3), 373-376(2009). https://doi.org/10.2109/jcersj2.117.373