Calcium Aluminate Phosphor Supported $TiO_2$ Nanoparticles

산화(酸化)티탄 나노입자(粒子)가 담지(擔持)된 칼슘 알루미늄 형광체(螢光體)

  • Thube, Dilip R. (Energy Materials Research Centre, Korea Research Institute of Chemical Technology) ;
  • Kim, Jin-Hwan (Energy Materials Research Centre, Korea Research Institute of Chemical Technology) ;
  • Kang, Suk-Min (Energy Materials Research Centre, Korea Research Institute of Chemical Technology) ;
  • Ryu, Ho-Jin (Energy Materials Research Centre, Korea Research Institute of Chemical Technology)
  • ;
  • 김진환 (한국화학연구원 에너지소재연구센터) ;
  • 강석민 (한국화학연구원 에너지소재연구센터) ;
  • 류호진 (한국화학연구원 에너지소재연구센터)
  • Published : 2009.08.27

Abstract

Rare earth based calcium aluminate phosphor ($CaAl_2O_4:Eu^{2+}$, $Nd^{3+}$) supported $TiO_2$ nanoparticles are synthesized by using sol-gel method, which are further characterized using powder X-ray diffraction (XRD), fourier transform infrared (FT-IR), diffuse reflectance UV-Visible spectroscopy (DRS UV-Vis) and transmission electron microscopy (TEM). The XRD pattern of as-prepared and sintered phosphor supported $TiO_2$ does not show the tendency to change the crystal structure from anatase to rutile phase up to $600^{\circ}C$. This indicates that the phosphor support might inhibit the densification and crystallite growth by providing dissimilar boundaries. The diffuse reflectance spectral (DRS) measurements showed shift towards longer wavelength indicating reduction in the band-gap energy as compared to free $TiO_2$. The FT-IR spectra of phosphor supported $TiO_2$ nanoparticles show shift in the peak positions to lower wavelengths. This indicates that the $TiO_2$ nanoparticles are not free, but covalently bonded to the phosphor support. TEM micrographs show presence of crystalline and spherical $TiO_2$ nanoparticles (8 - 15 nm diameter) dispersed uniformly on the surface of phosphor.

희토류 원소를 기반으로한 알루미늄산 형광체에 담지된 산화티탄은 졸겔방법 으로 제조되었다. 이렇게 제조된 산화티탄 나노입자의 재료물성을 분석하기 위해 XRD, FT-IR, DRS UV-Vis, TEM 측정을 실시하였다. 형광체에 담지된 산화티탄 입자의 소결 전후의 XRD분석결과는 600도 이상의 온도에서 아나타제에서 루틸로 상변화가 일어나지 않았다. 600도 이상의 온도에서 지속적인(장시간) 열처리 후에도 형광체에 담지된 산화티탄이 결정화도가 높은 아나타제로 존재 하는 것은 형광체 지지체와 담지된 산화티탄의 서로 다른 결정입계에 의하여 결정성장과 상변화에 필요한 치밀화가 억제되기 때문으로 판단된다. DRS측정결과 형광체에 담지된 산화티탄은 산화티탄이 없는 형광체에 비하여 보다 긴 장파로 쉬프트한 것은 밴드갭 에너지의 환원을 나타낸다. 이러한 형광체에 담지된 산화티탄의 FT-IR 스펙트럼은 피크의 위치가 더 높은 파수로 이동하였다. 이것은 산화티탄 입자와 지지체 사이의 공유결합이 관계하기 때문 이라 판단된다. TEM 이미지는 형광체 지지체에 다른 입자 크기로 담지되어 있는 산화티탄의 분산, 결정화 및 입자 형상을 나타낸다.

Keywords

References

  1. X. Chen, and S. S. Mao, 2007: Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications, Chem. Rev. 107, pp. 2891-2959 https://doi.org/10.1021/cr0500535
  2. D. F. Ollis, and C. S. Turchi, 1990: Heterogeneous photocatalysis for water purification: Contaminant mineralization kinetics and elementary reactor analysis, Environ. Prog. 9, pp. 229-234 https://doi.org/10.1002/ep.670090417
  3. D. W. Bahnemann, E. Pelizzetti, and M. Schiavello (Eds.), 1991: Photochemical Conversion and Storage of Solar Energy, Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 251-276
  4. M. R. Hoffmann, S. T. Martin, W. Choi, and D. W. Bahnemann, 1995:Environmental Applications of Semiconductor Photocatalysis, Chem. Rev. 95, pp. 69-96 https://doi.org/10.1021/cr00033a004
  5. A. Mills, and S. L. Hunte, 1997: An Overview of Semiconductor Photocatalysis, J. Photochem. Photobiol. A 108, pp. 1-35
  6. M. A. Fox, and M. T. Dulay, 1993: Heterogenous Photocatalysis, Chem. Rev. 93, pp. 341-357 https://doi.org/10.1021/cr00017a016
  7. M. V. Shankar, S. Anandan, N. Venkatachalam, B. Arbindoo, and V. Murugesan, 2004: Novel thin-film reactor for photocatalytic degradation of pesticides in an aqueous solution, J. Chem. Technol. Biotechnol. 79, pp. 1279-1285 https://doi.org/10.1002/jctb.1124
  8. T. L. Thompson, and J. T. Yates-Jr, 2006: Surface Science Studies of the Photoactivation of TiO$_{2}$ New Photochemical Process, Chem. Rev. 106, pp. 4428-4453 https://doi.org/10.1021/cr050172k
  9. S. Sakthivel, and H. Kisch, 2003: Daylight Photocatalysis by Carbon-Modified Titanium Dioxide, Angew. Chem. Int. Ed., 42, pp. 4908-4911 https://doi.org/10.1002/anie.200351577
  10. H. lrie, Y. Watanabe, and K. Hashimoto, 2003: Carbondoped Anatase TiO$_{2}$ Powders as a Visible-light Sensitive Photocatalyst, Chem. Lett. 32, pp. 772-774 https://doi.org/10.1246/cl.2003.772
  11. T. Umebayashi, T. Yamaki, S. Tanaka, and K. Asai, 2003:Visible Light-Induced Degradation of Methylene Blue on S-doped TiO$_{2}$, Chem. Lett., 32, pp. 330-332 https://doi.org/10.1246/cl.2003.330
  12. T. Ohno, T. Mitsui, and M. Matsumura, 2003: Visible Light-Induced Degradation of Methylene Blue on S-doped TiO$_{2}$, Chem. Lett., 32, pp. 364-365 https://doi.org/10.1246/cl.2003.364
  13. J. C. Yu, J. G. Yu, W. K. Ho, Z. T. Jiang, and L. Z. Zhang, 2002: Effects of P- Doping on the Photocatalytic Activity and Microstructures of Nanocrystalline TiO$_{2}$ Powders, Chem. Mater., 14, pp. 3808-3816 https://doi.org/10.1021/cm020027c
  14. T. Lindgren, J. M. Mwabora, E. Avendano, J. Jonsson, A. Hoel, C.-G. Granqvist, and S.-E. Lindquist, 2003: Photoelectrochemical and Optical Properties of Nitrogen Doped Titanium Dioxide Films Prepared by Reactive DC Magnetron Sputtering, J. Phys. Chem. B, 107, pp. 5709-5716 https://doi.org/10.1021/jp027345j
  15. T. Ihara, M. Miyoshi, Y. lriyama, 0. Matsumoto, and S. Sugihara, 2003: Visible-light-active titanium oxide photocatalyst realized by an oxygen-deficient structure and by nitrogen doping, Appl. Catal. B, 42, pp. 403-409 https://doi.org/10.1016/S0926-3373(02)00269-2
  16. C. Lettrnann, K. Hildenbrand, H. Kisch, W. Macyk, and W. F. Maier, 2001: Visible light photodegradation of 4-chlorophenol with a coke-containing titanium dioxide photocatalyst, Appl. Catal. B, 32, pp. 215-227 https://doi.org/10.1016/S0926-3373(01)00141-2
  17. W. Zhao, W. Ma, C. Chen, J. Zhao, and Z. Shuai, 2004:Efficient Degradation of Toxic Organic Pollutants with Ni$_{2}$O$_{3} /TiO$_{2-x}$B$_{x}$ under Visible Irradiation, J. Am. Chem. Soc., 126, pp. 4782-4783 https://doi.org/10.1021/ja0396753
  18. H. lrie, S.Washizuka, N. Yoshino, and K. Hashimoto, 2003:Visible-light induced hydrophilicity on nitrogensubstituted titanium dioxide films, Chem. Commun., pp.1298-1299
  19. H. lrie, Y. Watanabe, and K. Hashimoto, 2003: NitrogenConcentration Dependence on Photocatalytic Activity of TiO$_{2-x}$N$_{x}$ Powders, J. Phys. Chem. B, 107, pp. 5483-5486 https://doi.org/10.1021/jp030133h
  20. J.L. Gole, J.D. Stout, C. Burda, Y. Lou, and X. Chen, 2004:Highly Efficient Formation of Visible Light Tunable TiO$_{2-x}$N$_{x}$ Photocatalysts and Their Transformation at the Nanoscale, J. Phys. Chem. B, 108, pp. 1230-1240 https://doi.org/10.1021/jp030843n
  21. L. Lin, W. Lin, Y. X. Zhu, B. Y. Zhao, and Y. C. Xie, 2005:Phosphor-doped Titania -a Novel Photocatalyst Active in Visible Light, Chem. Lett., 34, pp. 284-285 https://doi.org/10.1246/cl.2005.284
  22. L. Lin, R. Y. Zheng, J. L. Xie, Y. X. Jhu, and Y. C. Xie, 2007: Synthesis and characterization of phosphor and nitrogen co-doped titania, App. Catal. B:Environ., 76, pp.196-202 https://doi.org/10.1016/j.apcatb.2007.05.023
  23. A. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, and Y. Taga, 2001: Visible-Light Photocatalysis in Nitrogen-Doped Titanium Oxides, Science, 293, pp. 269-271 https://doi.org/10.1126/science.1061051
  24. D. Shchukin, S. Poznyak, A. Kulak, and P. Pichat, 2004:TiO$_{2}$-In$_{2}$O$_{3}$ photocatalysts: preparation, characterizations and activity for 2-chlorophenol degradation in water, J. Photochem. Photobiol. A: Chem., 162, pp. 423-430 https://doi.org/10.1016/S1010-6030(03)00386-1
  25. S. Otsuka-Yao- Matsuo, and M. Ueda, 2004: Visible lightinduced photobleaching of methylene blue aqueous solution using (Sr$_{1x}$La$_{x}$)TiO$_{3+a}$- TiO$_{2}$ composite powder, J. Photochem. Photobiol. A: Chem., 168, pp. 1-6 https://doi.org/10.1016/j.jphotochem.2004.04.022
  26. P. Cheng, W. Li, T. Zhou, Y. Jin, and M. Gu, 2004: Physical and photocatalytic properties of zinc ferrite doped titania under visible light irradiation, J. Photochem. Photobiol' A:Chem., 168, pp. 97-101 https://doi.org/10.1016/j.jphotochem.2004.05.018
  27. F. X. Ye, T. Tsumura, K. Nakata, and A. Ohmoric, 2008:Dependence of photocatalytic activity on the compositions and photo-absorption of functional TiO$_{2}$-Fe$_{3}$O$_{4}$ coatings deposited by plasma spray, Mater. Sci. Eng. B, 148, pp.154-161 https://doi.org/10.1016/j.mseb.2007.09.057
  28. H. Wang, Y. Wu, and B. Q Xu, 2005: Preparation and characterization of nanosized anatase TiO$_{2}$ cuboids for photocatalysis, Appl. Catal. B Environ., 59, pp. 139-146 https://doi.org/10.1016/j.apcatb.2005.02.001
  29. R. S. Sonawane, B. B. Kale, and M. K. Dongare, 2004:Preparation and photo-catalytic activity of Fe-TiO$_{2}$ thin films prepared by sol-gel dip coating, Mater. Chem. Phys., 85, pp. 52-57 https://doi.org/10.1016/j.matchemphys.2003.12.007
  30. N. Venkatchalam, M. palanichamy, and V. Murugesan, 2007: Sol-gel preparation and characterization of nanosize TiO$_{2}$: Its photocatalytic performance, Mater. Chem. Phys., 104, pp. 454-459 https://doi.org/10.1016/j.matchemphys.2007.04.003
  31. J. N. Hart, L. Bourgeosis, R. Cervini, Y. B. Cheng, G. P. Simon, and L. Spiccia, 2007: Low temperature crystallization behavior of TiO$_{2}$ derived from a sol-gel process, J Sol-Gel Sci. Tech., 42, pp. 107-117 https://doi.org/10.1007/s10971-007-1536-8
  32. J. Zhang, F. Pan, W. Hao, Qi Ge, and T. Wang, 2004: Lightstoring photocatalyst, Appl. Phys. Letts., 85, pp. 5778-5781 https://doi.org/10.1063/1.1833554
  33. B. D. Cullity (Ed.), 1978: Elements of X-Ray Diffraction, 3rd Edn. Addision-Wesley, Reading, MA, pp. 102, 284
  34. A. K. Datye, G Riegel, J. R. Bolton, M. Haung, and M. R. Prairie, 1995: Microstructural Characterization of a Fumed Titanium Dioxide Photocatalyst, J. Solid State Chem., 115, pp. 236-239 https://doi.org/10.1006/jssc.1995.1126
  35. Y. H. Zhang, H. X. Zhang, Y. X. Xu, and Y. G Wang, 2004:Significant effect of lanthanide doping on the texture and properties of nanocrystalline mesoporous TiO$_{2}$, J. Solid State Chem., 177, pp. 3490-3498 https://doi.org/10.1016/j.jssc.2004.05.026
  36. S. Hishita, I. Mutoh, K. Koumoto, and H. Yanagida, 1983:Inhibition mechanism of the anatase-rutile phase transformation by rare earth oxides, Ceram. International, 9, pp.61-67 https://doi.org/10.1016/0272-8842(83)90025-1
  37. J. Nair, P. Nair, F. Mizukami, Y. Oosawa, and T. Okuba, 1999: Microstructure and phase transformation behavior of doped nanostructured titania, Mater. Res. Bull., 34, pp. 1275-1290 https://doi.org/10.1016/S0025-5408(99)00113-0
  38. N. Venkatchalam, M. Palanichamy, and V. Murugesan, 2007: Sol-gel preparation and characterization of alkaline earth metal doped nano TiO$_{2}$: Efficient photocatalytic degradation of 4-chlorophenol, J. Mol. Catal. A: Chem., 273, pp. 177-185 https://doi.org/10.1016/j.molcata.2007.03.077
  39. W. Bauer, and G Tomandl, 1994: Preparation of spherical TiO$_{2}$ particles by an emulsion method using TiCI$_{4}$, Ceram. International, 20, pp. 189-193 https://doi.org/10.1016/0272-8842(94)90038-8
  40. M. Ocana, V. Fornes, and C. J. Serna, 1992: A simple procedure for the preparation of spherical oxide particles by hydrolysis of aerosols, Ceram. International, 18, pp. 99-106 https://doi.org/10.1016/0272-8842(92)90038-F
  41. Z. Li, B. Hou, Y. Xu, D. Wu, and Y. Sun, 2005:Hydrothermal synthesis, characterization, and photocatalytic performance of silica-modified titanium dioxide nanoparticles, J. Colloid. Interface. Sci., 288, pp. 149-154 https://doi.org/10.1016/j.jcis.2005.02.082
  42. Z. Wang, L. Mao, and J. Lin, 2006: Preparation of TiO$_{2}$ nanocrystallites by hydrolyzing with gaseous water and their photocatalytic activity, J. Photochem. Photobiol. A:Chem., 177, pp. 261-268 https://doi.org/10.1016/j.jphotochem.2005.06.005
  43. D. S. Kim, S. J. Han, and S. Y. Kwak, 2007: Synthesis and photocatalytic activity of mesoporous TiO$_{2}$ with the surface area, crystallite size, and pore size, J. Colloid. Interface. Sci., 316, pp. 85-91 https://doi.org/10.1016/j.jcis.2007.07.037
  44. M. Anpo, T. Shima, S. Kodama, and Y. Kubokawa, 1987:Photocatalytic hydrogenation of propyne with water on small-particle titania: size quantization effects and reaction intermediates, J. Phys. Chem., 91, pp. 4305-4310 https://doi.org/10.1021/j100300a021
  45. S. Sivakumar, P. Krishna, P. Mukundan, and K. G K. Warrier, 2002: Sol-gel synthesis of nanosized anatase from titanyl sulfate, Mater. Lett., 57, pp. 330-335 https://doi.org/10.1016/S0167-577X(02)00786-3