Journal of Nanoparticle Research

, Volume 8, Issue 3–4, pp 379–393 | Cite as

Silica-based composite and mixed-oxide nanoparticles from atmospheric pressure flame synthesis

  • Kranthi K. Akurati
  • Rainer Dittmann
  • Andri Vital
  • Ulrich Klotz
  • Paul Hug
  • Thomas Graule
  • Markus Winterer


Binary TiO2/SiO2 and SnO2/SiO2 nanoparticles have been synthesized by feeding evaporated precursor mixtures into an atmospheric pressure diffusion flame. Particles with controlled Si:Ti and Si:Sn ratios were produced at various flow rates of oxygen and the resulting powders were characterized by BET (Brunauer–Emmett–Teller) surface area analysis, XRD, TEM and Raman spectroscopy. In the Si–O–Ti system, mixed oxide composite particles exhibiting anatase segregation formed when the Si:Ti ratio exceeded 9.8:1, while at lower concentrations only mixed oxide single phase particles were found. Arrangement of the species and phases within the particles correspond to an intermediate equilibrium state at elevated temperature. This can be explained by rapid quenching of the particles in the flame and is in accordance with liquid phase solubility data of Ti in SiO2. In contrast, only composite particles formed in the Sn–O–Si system, with SnO2 nanoparticles predominantly found adhering to the surface of SiO2 substrate nanoparticles. Differences in the arrangement of phases and constituents within the particles were observed at constant precursor mixture concentration and the size of the resultant segregated phase was influenced by varying the flow rate of the oxidant. The above effect is due to the variation of the residence time and quenching rate experienced by the binary oxide nanoparticles when varying the oxygen flow rate and shows the flexibility of diffusion flame aerosol reactors.


flame aerosol process atmospheric pressure mixed oxide composite SiO2 SnO2 TiO2 


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The authors would like to acknowledge the EC and the Swiss BBW for their support of the FP5-Project Photocoat (EU contract No G5RD-CT-2002-00861; BBW project No 01.0571-1) and also Dr. Markus Wegmann and Dr. R.B. Diemer for their contributions to this work.


  1. Aizawa M., Nosaka Y., Fujii N. (1991). FT-IR liquid attenuated total reflection study of TiO2-SiO2 sol-gel reaction. J. Non-Cryst. Solids 128: 77–85CrossRefGoogle Scholar
  2. Anderson C., Bard A.J. (1995). An improved photocatalyst of TiO2/SiO2 prepared by a sol-gel synthesis. J. Phys. Chem. 99: 9882–9885CrossRefGoogle Scholar
  3. Astier M., Vergnon P. (1976). Determination of the diffusion coefficients from sintering data of ultrafine oxide particles. J. Solid State Chem. 19: 67–73CrossRefGoogle Scholar
  4. Atik M., Zarzycki J. (1994). Protective TiO2-SiO2 coatings on stainless-steel sheets prepared by dip-coating. J. Mater. Sci. Lett. 13:1301–1304CrossRefGoogle Scholar
  5. Backer M.R., R. Cavender, M.L. Elder, P.C. Jones & J.A. Murphy, 1991. U.S. Patent number 5,067,975.Google Scholar
  6. Bordiga S., Coluccia S., Lamberti C., Marchese L., Zecchina A., Boscherini F., Buffa F., Genoni F., Leofanti G., Petrini G., Vlaic G. (1994) XAFS study of Ti-silicalite: Structure of framework Ti(IV) in the presence and absence of reactive molecules (H2O, NH3) and comparison with ultraviolet-visible and IR results. J. Phys. Chem. 98: 4125–4132CrossRefGoogle Scholar
  7. Brambilla G., Pruneri V., Reekie L. (2000). Photorefractive index gratings in SnO2:SiO2 optical fibers. Appl. Phys. Lett. 76: 807–809CrossRefGoogle Scholar
  8. Brinker C.J., Kirkpatrick R.J., Tallant D.R., Bunker B.C., Montez B. (1988). NMR confirmation of strained “defects" in amorphous silica. J. Non-Cryst. Solids 99: 418–428CrossRefGoogle Scholar
  9. Canevali C., Chiodini N., Morazzoni F., Padovani J., Paleari A., Scotti R., Spinolo G. (2001). Substitutional tin-doped silica glasses: An infrared study of the sol–gel transition. J. Non-Cryst. solids 293-295: 32–38CrossRefGoogle Scholar
  10. Cardoso W.S., Francisco M.S.P., Lucho A.M.S., Gushilem Y. (2004) Synthesis and acidic properties of the SiO2/SnO2 mixed oxides obtained by the sol–gel process. Evaluation of immobilized copper hexacyanoferrate as an electrochemical probe. Solid State Ionics 167:165–173CrossRefGoogle Scholar
  11. Carturan G., Ceccato R., Principi G., Russo U. (1995) Structural-analysis of mixed tin oxides produced by the sol-gel method. J. Radioanal. Nucl. Chem. 190:419–423CrossRefGoogle Scholar
  12. Chiodini N., Paleari A., DiMartino D., Spinolo G. (2002). SnO2 nanocrystals in SiO2: A wide-band-gap quantum-dot system. Appl. Phys. Lett. 81:1702–1704CrossRefGoogle Scholar
  13. Chiodini N., Paleari A., Spinolo G., Crespi P. (2001). Photorefractivity in SiO2:SnO2 glass-ceramics by visible light. J. Non-Cryst. Solids 322:266–271CrossRefGoogle Scholar
  14. Chiodini N., Morazzoni F., Paleari A., Scotti R., Spinolo G. (1999). Sol–gel synthesis of monolithic tin-doped silica glass. J. Mater. Chem. 9:2653–2658CrossRefGoogle Scholar
  15. Cox D.F., Fryberger T.B., Semancik S. (1998). Oxygen vacancies and defect electronic states on the SnO2(110)-1×1 surface. Phys. Rev. B 38:2072–2083CrossRefGoogle Scholar
  16. Dagan G., Sampath S., Lev O. (1995). Preparation and utilization of organically modified silica-titania photocatalysts for decontamination of aquatic environments. Chem. Mater. 7:446–453CrossRefGoogle Scholar
  17. DeVries R.C., Roy R., Osborn E.F. (1954) The system TiO2-SiO2. Trans. Brit. Ceram. Soc. 53:525–540Google Scholar
  18. Ehrmann S.H., Friedlander S.K., Zachariah M.R. (1998) Characteristics of SiO2/TiO2 nanocomposite particles formed in a premixed flat flame. J. Aerosol Sci. 29:687–706CrossRefGoogle Scholar
  19. Ehrmann S.H., Friedlander S.K., Zachariah M.R. (1999) Phase segregation in binary SiO2/TiO2 and SiO2/Fe2O3 nanoparticle aerosols formed in a premixed flame. J. Mater. Res. 14:4551–4561Google Scholar
  20. Feng Y.S., Zhou S.M., Li Y., Zhang L.D. (2003). Preparation of the SnO2/SiO2 xerogel with a large specific surface area. Mater. Lett. 57:2409–2412CrossRefGoogle Scholar
  21. Gao X., Bare S.R., Fierro J.L.G., Banares M.A., Wachs I.E. (1998) Preparation and in-situ spectroscopic characterization of molecularly dispersed titanium oxide on silica. J. Phys. Chem. B. 102:5653–5666CrossRefGoogle Scholar
  22. Harrison P.G., Willett M.J. (1989). Tin oxide surfaces. J. Chem. Soc. Farady Trans. 85:1921–1932CrossRefGoogle Scholar
  23. Hung C.H., Katz J.L. (1992). Formation of mixed oxide powders in flames: Part I. TiO2–SiO2. J. Mater. Res. 7:1861–1869Google Scholar
  24. Ishida T., Kobayashi H., Nakato Y. (1993). Structures and properties of electron-beam-evaporated indium tin oxide films as studied by x-ray photoelectron spectroscopy and work-function measurements. J. Appl. Phys. 73: 4344–4350CrossRefGoogle Scholar
  25. Jang H.D., Kim S.K. (2001) Controlled synthesis of titanium dioxide nanoparticles in a modified diffusion flame reactor. Mater. Res. Bull. 36:627–637CrossRefGoogle Scholar
  26. Johannessen T., Pratsinis S.E., Livbjerg H. (2001) Computational analysis of coagulation and coalescence in the flame synthesis of titania particles. Powder Technol. 118:242–250CrossRefGoogle Scholar
  27. Kennedy M.K., Kruis F.E., Fissan H. (2000). Gas phase synthesis of size selected SnO2 nanoparticles for gas sensor applications. J. Metastable and Nanocryst. Mat. 8:949–954Google Scholar
  28. Kingery W.D., Bowen H.K., Uhlmann D.R. (1976) Introduction to Ceramics. Wiley-Interscience, New York 494Google Scholar
  29. Kodas T.T., Engler E.M., Lee V.Y. (1989). Generation of thick Ba2YCu3O7 films by aerosol deposition. Appl. Phys. Lett. 54:1923–1925CrossRefGoogle Scholar
  30. Lee S.K., Chung K.W., Kim S.G. (2002) Preparation of various composite TiO2/SiO2 ultrafine particles by vapor-phase hydrolysis. Aerosol. Sci. Tech. 36:763–770CrossRefGoogle Scholar
  31. Lindackers D., Janzen C., Rellinghaus B., Wassermann E.F., Roth P. (1998) Synthesis of Al2O3 and SnO2 particles by oxidation of metalorganic precursors in premixed H2/O2/Ar low pressure flames. Nanostruct. Mater. 10: 1247–1270CrossRefGoogle Scholar
  32. Miller J.B., Johnston S.T., Ko E.I. (1994) Effect of prehydrolysis on the textural and catalytic properties of titania-silica aerogels. J. Catal. 150:311–320CrossRefGoogle Scholar
  33. Miyamoto Y., Kirihara S., Kanehira S. (2004) Smart processing development of photonic crystals and fractals. Int. J. Appl. Ceram. Technol. 1:40–48CrossRefGoogle Scholar
  34. Morrow B.A., Mcfarlan A.J. (1990) Chemical reactions at silica surfaces. J. Non-Cryst. Solids. 120:61–71CrossRefGoogle Scholar
  35. Mueller R., Kammler H.K., Pratsinis S.E., Vital A., Beaucage G., Burtscher P. (2004). Non-agglomerated dry silica nanoparticles. Powder Technol. 140:40–48CrossRefGoogle Scholar
  36. Niles D.W., Rioux D., Hochst H. (1993) A photoemission investigation of the SnO2/CdS interface: A front contact interface study of CdS/CdTe solar cells. J. Appl. Phys. 73: 4586–4590CrossRefGoogle Scholar
  37. Popova L., Djulgerova R., Beshkov G., Mihailov V., Szytula A., Gondek L., Petrovic Z.j. (2004) SnO2 thin films for gas sensors modified by hexamethyldisilazane after rapid thermal annealing. Sensor. Actuat. B-Chem. 100:357–363CrossRefGoogle Scholar
  38. Powell Q.H., Fotou G.P., Kodas T.T., Anderson B.M., Guo Y.X. (1997). Gas-phase coating of TiO2 with SiO2 in a continuous flow hot-wall aerosol reactor. J. Mater. Res. 12: 552–559Google Scholar
  39. Pratsinis S.E., Vemury S. (1996) Particle formation in gases: A review. Powder Technol. 88:267–273CrossRefGoogle Scholar
  40. Sahm T., Maedler L., Gurlo A., Barsan N., Pratsinis S.E., Weimar U. (2004). Flame spray synthesis of tin dioxide nanoparticles for gas sensing. Sensor. Actuat. B-Chem. 98:148–153CrossRefGoogle Scholar
  41. Salas P., Hernandez J.G., Montoya J.A., Navaretter J., Salmones J., Schifter I., Morales J. (1997) Effect of tin content on silica mixed oxides: Sulfated and unsulfated catalysts. J. Mol. Catal. A: Chem. 123:149–154CrossRefGoogle Scholar
  42. Song Y., Sakurai T., Kishimoto K., Maruta K., Matsumoto S., Kikuchi K. (1998) Synthesis and optical properties of low-temperature SiOx and TiOx thin films prepared by plasma enhanced CVD. Vacuum 51:525–530CrossRefGoogle Scholar
  43. Schultz P.C. (1976). Binary titania-silica glasses containing 10 to 20 Wt% TiO2. J. Amer. Ceram. Soc. 59:214–219CrossRefGoogle Scholar
  44. Slater B., Catlow C.R.A., Gay D.H., Williams D.E., Dusastre V. (1999). Study of surface segregation of antimony on SnO2 surfaces by computer simulation techniques. J. Phys. Chem. B 103:10644–10650CrossRefGoogle Scholar
  45. Srinivasan S., Datye A.K., Smith M.H., Peden C.H.F. (1994) Interaction of titanium isopropoxide with surface hydroxyls on Silica. J. Catal. 145:565–573CrossRefGoogle Scholar
  46. Stakheev A.Y., Shpiro E.S., Apijok J. (1993) XPS and XAES study of titania-silica mixed oxide system. J. Phys. Chem. 97: 5668–5672CrossRefGoogle Scholar
  47. Stark W.J., Pratsinis S.E., Baiker A. (2001) Flame made titania/silica epoxidation catalysts. J. Catal. 203:516–524CrossRefGoogle Scholar
  48. Vemury S., Pratsinis S.E., Kibbey L. (1997) Electrically controlled flame synthesis of nanophase TiO2, SiO2 and SnO2 powders. J. Mater. Res. 12:1031–1042Google Scholar
  49. Vemury S., Pratsinis S.E. (1995) Dopants in flame synthesis of titania. J. Am. Ceram. Soc. 78:2984–2992CrossRefGoogle Scholar
  50. Wegner K., Pratsinis S.E. (2003a) Scale-up of nanoparticle synthesis in diffusion flame reactors. Chem. Eng. Sci. 58:4581–4589CrossRefGoogle Scholar
  51. Wegner K., Pratsinis S.E. (2003b) Nozzle-quenching process for controlled flame synthesis of titania nanoparticles. AIChE Journal. 49:1667–1675CrossRefGoogle Scholar
  52. Yu-Zhang K., Boisjolly G., Rivory J., Kilian L., Colliex C. (1994) Characterization of TiO2/SiO2 multilayers by high resolution transmission electron microscopy and electron energy loss spectroscopy. Thin Solid Films 253:299–302CrossRefGoogle Scholar
  53. Zhu D., Kosugi T. (1996) Thermal conductivity of GeO2-SiO2 and TiO2-SiO2 mixed glasses. J. Non-Cryst. Solids 202:88–92CrossRefGoogle Scholar
  54. Zhu W., Pratsinis S.E. (1997) Synthesis of SiO2 and SnO2 particles in diffusion flame reactors. AIChE Journal. 43:2657–2664CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • Kranthi K. Akurati
    • 1
  • Rainer Dittmann
    • 1
  • Andri Vital
    • 1
  • Ulrich Klotz
    • 1
  • Paul Hug
    • 1
  • Thomas Graule
    • 1
  • Markus Winterer
    • 2
  1. 1.Laboratory for High Performance CeramicsSwiss Federal Laboratories for Materials Testing and Research (EMPA)DuebendorfSwitzerland
  2. 2.Nanoparticle Process Technology, Institute of Combustion and Gas DynamicsUniversity of Duisburg-EssenDuisburgGermany

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