Abstract
Thermal decomposition of an amorphous precursor for S-doped titania (TiO2) nanopowders, prepared by controlled sol–gel hydrolysis–condensation of titanium(IV) tetraethoxide and thiourea in aqueous ethanol, has been studied up to 800 °C in flowing air. Simultaneous thermogravimetric and differential thermal analysis coupled online with quadrupole mass spectrometer (TG/DTA-MS) and FTIR spectrometric gas cell (TG-FTIR) have been applied for analysis of released gases (EGA) and their evolution dynamics in order to explore and simulate thermal annealing processes of fabrication techniques of the aimed S:TiO2 photocatalysts with photocatalytic activities under visible light. The precursor sample prepared with thiourea, released first water endothermically from room temperature to 190 °C, carbonyl sulfide (COS) from 120 to 240 °C in two stages, ammonia (NH3) from 170 to 350 °C in three steps, and organic mater (probably ether and ethylene) between 140 and 230 °C. The evolution of CO2, H2O and SO2, as oxidation products, occurs between 180 and 240 °C, accompanied by exothermic DTA peaks at 190 and 235 °C. Some small mass gain occurs before the following exothermic heat effect at 500 °C, which is probably due to the simultaneous burning out of residual carbonaceous and sulphureous species, and transformation of amorphous titania into anatase. The oxidative process is accompanied by evolution of CO2 and SO2. Anatase, which formed also in the exothermic peak at 500 °C, mainly keeps its structure, since only 10% of rutile formation is detected below or at 800 °C by XRD. Meanwhile, from 500 °C, a final burning off organics is also indicated by continuous CO2 evolution and small exothermic effects.
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References
Bacsa R, Kiwi J, Ohno T, Albers P, Nadtochenko V. Preparation, testing and characterization of doped TiO2 active in the peroxidation of biomolecules under visible light. J Phys Chem B. 2005;109:5994–6003 (and references therein).
Asahi R, Morikawa T, Ohwaki T, Aoki K, Taga Y. Visible-light photocatalysis in nitrogen-doped titanium oxides. Science. 2001;293:269–71.
Umebayashi T, Yamaki T, Tanaka S, Asai K. Visible light-induced degradation of methylene blue on S-doped TiO2. Chem Lett. 2003;32:330–1.
Ohno T, Mitsui T, Matsumura M. Photocatalytic activity of S-doped TiO2 photocatalyst under visible light. Chem Lett. 2003;32:364–5.
Ohno T, Akiyoshi M, Umebayashi T, Asai K, Mitsui T, Matsumura M. Preparation of S-doped TiO2 photocatalysts and their photocatalytic activities under visible light. Appl Catal A: Gen. 2004;265:115–21.
Ohno T. Preparation of visible light active S-doped TiO2 photocatalysts and their photocatalytic activities. Water Sci Technol. 2004;49:159–63.
Tachikawa T, Toja S, Kawai K, Endo M, Fujitsuka M, Ohno T, et al. Photocatalytic oxidation reactivity of holes in the sulfur- and carbon-doped TiO2 powders studied by time-resolved diffuse reflectance spectroscopy. J Phys Chem. 2004;108:19299–306.
Takeshita K, Yamakata A, Ishibashi T, Onishi H, Nishijima K, Ohno T. Transient IR absorption study of charge carriers photogenerated in sulfur-doped TiO2. J Photochem Phytobiol A: Chem. 2006;177:269–75.
Ohno T, Miyamoto Z, Nishijima K, Kanemitsu H, Xueyuan F. Sensitization of photocatalytic activity of S- or N-doped TiO2 particles by absorbing Fe3+ cations. Appl Catal A: Gen. 2006;302:62–8.
Sakthivel S, Janczarek M, Kisch H. Visible light activity and photoelectrochemical properties of nitrogen-doped TiO2. J Phys Chem B. 2004;108:19384–7.
Sun H, Bai Y, Cheng Y, Jin W, Xu N. Preparation and characterization of visible-light-driven carbon–sulfur-codoped TiO2 photocatalysts. Ind Eng Chem Res. 2006;45:4971–6.
Ohno T, Tsubota T, Toyofuku M, Inaba R. Photocatalytic activity of a TiO2 photocatalyst doped with C4+ and S4+ ions having a rutile phase under visible light. Catal Lett. 2004;98:255–8.
Yin S, Ihara K, Aita Y, Komatsu M, Sato T. Visible-light induced photocatalytic activitity of TiO2−x A y (A = N, S) prepared by precipitation route. J Photochem Phytobiol A: Chem. 2006;179:105–14.
Xie Y, Zhao Q, Zhao XJ, Li J. Low-temperature preparation and characterization of N-doped and N–S-codoped TiO2 by sol–gel route. Catal Lett. 2007;118:231–7.
Nishijima K, Kamai K, Murakami N, Tsubota T, Ohno T. Photocatalytic hydrogen or oxygen evolution from water over S- or N-doped TiO2 under visible light. Int J Photoenerg 2008; Article ID 173943, 2008. doi: 10.1155/2008/173943.
Crişan M, Brăileanu A, Răileanu M, Crişan D, Teodorescu VS, Bîrjega R, et al. TiO2-based nanopowders obtained from different Ti-alkoxides. J Therm Anal Calorim. 2007;88:171–6.
Campostrini R, Ischia M, Palmisano L. Pyrolysis study of sol–gel derived TiO2 powders Part I. TiO2–anatase prepared by reacting titanium(IV) isopropoxide with formic acid. J Therm Anal Calorim. 2003;71:997–1009.
Campostrini R, Ischia M, Palmisano L. Pyrolysis study of sol–gel derived TiO2 powders Part I. TiO2-anatase prepared by reacting titanium(IV) isopropoxide with oxalic acid. J Therm Anal Calorim. 2003;71:1011–21 (and references therein).
Campostrini R, Ischia M, Palmisano L. Pyrolysis study of sol–gel derived TiO2 powders Part I. TiO2-anatase prepared by reacting titanium(IV) isopropoxide with acetic acid. J Therm Anal Calorim. 2004;75:13–24.
Campostrini R, Ischia M, Palmisano L. Pyrolysis study of sol–gel derived TiO2 powders Part I. TiO2-anatase prepared by reacting titanium(IV) isopropoxide without chelating agents. J Therm Anal Calorim. 2004;75:25–34.
Oja-Açik I, Madarász J, Krunks M, Tõnsuaadu K, Janke D, Pokol G, et al. Thermoanalytical studies of titanium(IV) acetylacetonate xerogels with emphasis on evolved gas analysis. J Therm Anal Calorim. 2007;88:557–63.
Krunks M, Madarász J, Hiltunen L, Mannonen R, Mellikov E, Niinistö L. Structure and thermal behaviour of dichlorobis(thiourea)cadmium(II), a single-source precursor for CdS thin films. Acta Chem Scand. 1997;51:294–301.
Madarász J, Bombicz P, Okuya M, Kaneko S, Pokol G. Online coupled TG-FTIR and TG/DTA-MS analyses of the evolved gases from dichloro(thiourea) tin(II). Solid State Ionics. 2004;172:577–81.
Madarász J, Bombicz P, Okuya M, Kaneko S, Pokol G. Comperative online coupled TG-FTIR and TG/DTA-MS analyses of the evolved gases from thiourea complexes of SnCl2. Tetrachloropenta(thiourea) ditin(II), a compound rich in thiourea. J Anal Appl Pyrol. 2004;72:209–14.
Madarász J, Krunks M, Niinistö L, Pokol G. Evolved gas analysis of dichlorobis(thiourea)zinc(II) by coupled TG-FTIR and TG/DTA-MS techniques. J Therm Anal Calorim. 2004;78:679–86.
Madarász J, Pokol G. Comparative evolved gas analyses on thermal degradation of thiourea by coupled TG-FTIR and TG/DTA-MS instruments. J Therm Anal Calorim. 2007;88:329–36 (and references therein).
Venz PA, Frost RL, Bartlett JR, Woolfrey JL, Kloprogge JT. Thermal transformations of titania hydrolysates prepared from tetraisopropoxytitanium(IV). Thermochim Acta. 2000;346:73–82.
Hardy A, D’Haen J, Van Bael MK, Mullens J. An aqueous solution-gel citratoperoxo-Ti(IV) precursor: synthesis, gelation, thermo-oxidative decomposition and oxid crystallization. J Sol–Gel Sci Technol. 2007;44:65–74.
Madarász J, Okuya M, Kaneko S, Pokol G. Thermal behavior of Ti-precursor sols for porous TiO2 thin films. Solid State Ionics. 2004;172:515–8.
Madarász J, Okuya M, Varga PP, Kaneko S, Pokol G. TG/DTA-MS studies on titania precursors with low content of organics for porous thin films of TiO2. J Anal Appl Pyrol. 2007;79:479–83.
Madarász J, Kaneko S, Okuya M, Pokol G. Comparative evolved gas analyses of crystalline and amorphous titanium(IV)oxo-hydroxo-acetylacetonates by TG-FTIR and TG/DTA-MS. Thermochim Acta. 2009;489:37–44. doi: 10.1016/j.tca.2009.01.020.
Crişan M, Brăileanu A, Răileanu M, Zaharescu M, Crişan D, Drăgan N, et al. Sol–gel S-doped TiO2 materials for environmental protection. J Non-Cryst Solids. 2008;354:705–11.
Madarász J, Brăileanu A, Pokol G. Comprehensive evolved gas analysis of amorphous precursors for S-doped titania by in situ TG-FTIR and TG/DTA-MS. Part 1. Precursor from thiourea and titanium(IV)-isopropoxide. J Anal Appl Pyrol. 2008;82:292–7.
Madarász J, Brăileanu A, Crişan M, Pokol G. Comprehensive evolved gas analysis of amorphous precursors for S-doped titania by in situ TG-FTIR and TG/DTA-MS: Part 2. Precursor from thiourea and titanium(IV)-n-butoxide. J Anal Appl Pyrol. 2009;85:549-56. doi: 10.1016/j.jaap.2008.10.017.
NIST Chemistry Webbook Standard Reference Database No 69, June 2009 Release. http://webbook.nist.gov/chemistry.
Spectral Database for Organic Compounds, SDBS, National Institute of Advanced Industrial Science and Technology, Japan. http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi.
Ischia M, Campostrini R, Lutterotti L, Gracia-Lopez E, Palmisano L, Schiavello M, et al. Synthesis, characterization and photocatalytic activity of TiO2 powders prepared under different gelling and pressure conditions. J Sol–Gel Sci Technol. 2005;33:201–13.
Ren L, Huang X, Sun F, He X. Preparation and characterization of doped TiO2 nanodandelion. Mater Lett. 2007;61:427–31.
Nishide T, Tanaka T, Yabe T. Temperature programmed desorption analysis of sol-gel-derived titania films. Design of a sol preparation procedure. J Therm Anal Calorim. 2007;90:373–8.
Toshikazu N, Takayuki Y, Nobuyoshi M, Makiko S. Analysis of firing processes of titania gel films fabricated by sol–gel processes. Thin Solid Films. 2004;467:43–9.
International Centre for Diffraction Data (ICDD), Powder Diffraction File (PDF), PDF-2 Release 2008.
Acknowledgements
The authors thank Mrs. H. Medzihradszky for the elemental analysis measurements. The purchase of our new HT-XRD apparatus has been supported by the EU (GVOP-3.2.1.-2004-04-0224, KMA) and the Hungarian Government.
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Madarász, J., Brăileanu, A., Crişan, M. et al. Evolved gas analysis of amorphous precursors for S-doped TiO2 by TG-FTIR and TG/DTA-MS. J Therm Anal Calorim 97, 265 (2009). https://doi.org/10.1007/s10973-009-0235-9
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DOI: https://doi.org/10.1007/s10973-009-0235-9